Dissertations / Theses: 'Pasture systems'

1

Emenheiser, Joseph Carl. "Economic Pasture-Based Cow-Calf Systems for Appalachia." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/24787.

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Pasture-based beef production is well-suited for the Appalachian region of the United States. This research investigated pasture, beef cattle, and economics components within the cow-calf sector of pasture beef production, and presents implications of their interplay for the vitality of the whole system. Samples of forage DM mass and CP, ADF, NDF, and ash contents in each paddock of a rotational stocking system were collected monthly for 4 grazing seasons. Effects of month, stockpiling, hay feeding, temperature, precipitation, and durations of paddock grazing and rest on forage mass and quality measurements were investigated. The system was complex and dynamic; precipitation and rest days in particular showed clear interactions with both month and stockpiling when predicting forage mass and quality. Available DM, TDN, and CP were compared to nutrient density requirements for beef cows to conclude that the system met or exceeded requirements. Six years of production data from a spring-calving cow-calf enterprise that utilized rotational stocking and fall stockpiling were analyzed. Comparisons among 2 cow frame size and 2 calf creep system treatments for production efficiency (total weaning weight per land area), and net returns to the enterprise, were made. Pastures with medium frame cows and designated creep systems had the greatest production efficiency, but also had the highest costs and netted the least returns. Greatest net returns were achieved in large frame, forward creep systems, which had the lowest production efficiency but also the lowest costs. Provided the quality of calves produced is suitable for other phases of the production stream, we conclude that minimizing costs rather than maximizing productive outputs is a better focus for cow-calf enterprises faced with similar decisions among frame size and creep system treatments.
Ph. D.

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2

Jones, Gordon B. "Temporal Nutrient Dynamics in Cool-Season Pasture." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23143.

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Understanding the nutrient dynamics of pastures is essential to their profitable and sustainable management. Tall fescue [Schendonorus phoenix (Scop.) Holub.] is the predominant forage species in Virginia pasturelands. Although tall fescue pasture is common, little research has attempted to document how soil and herbage nutrient concentrations change through time. This thesis summarizes two studies conducted within the context of a larger grazing systems project near Steele\'s Tavern, VA. The objectives were to: (1) examine temporal changes in plant available soil nutrient concentrations in four grazing systems, (2) determine how hay feeding and use of improved forages affected soil and herbage nutrient concentrations (3) examine the relationship between and variability within soil and herbage nutrient concentrations, (4) analyze the seasonal variation in herbage mineral concentration with regard to beef cattle requirements, and (5) create a statistical model to predict variation in herbage mineral concentration across the growing season. Analysis of plant and soil nutrients through 5 years of grazing produced several important findings. Soil pH, P, and Ca, Mg, and B declined through five years of grazing. Higher concentrations of herbage N and K and soil P, K, Fe, Zn, and Cu were measured in hay feeding paddocks. Herbage nutrient concentrations showed less variability in P and K than did soil test results. Fertility testing in pastures is important to monitor changing nutrient concentrations, and this study showed that herbage analysis may provide a more stable and accurate assessment of pasture fertility than soil testing. Pasture herbage, grown without fertilization, contained sufficient concentrations of macronutrients to meet the requirements of dry beef cows through the growing season and to meet the requirements of lactating beef cows in April. A model was developed using soil moisture and relative humidity that predicted (R2 = 0.75) variation in herbage mineral concentration throughout the growing season. As described in this thesis, use of modeling to predict nutrient dynamics in pasture could allow for more efficient mineral supplementation strategies that lead to improved profitability, nutrient retention, and livestock health.

Master of Science

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3

Evans, Jason R. "An economic analysis of pasture-raised beef systems in Appalachia." Morgantown, W. Va. : [West Virginia University Libraries], 2003. http://etd.wvu.edu/templates/showETD.cfm?recnum=3193.

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Thesis (M.S.)--West Virginia University, 2003.
Title from document title page. Document formatted into pages; contains vi, 163 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 132-136).

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4

Svinurai, Walter. "Manure production and nutrient management in pasture-based dairy production systems." Thesis, University of Fort Hare, 2010. http://hdl.handle.net/10353/475.

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Manure production and nutrient management in pasture-based dairy production systems by Walter Svinurai The effect of dietary treatments on nutrient excretion was determined and an attempt to improving the retention of excreted nitrogen in stored manure using Aloe ferox leaf gel (AFLG) and pine bark was conducted at a pasture-based dairy farm. The animal mass-balance method was used to determine nutrient excretion by cows fed on three dietary treatments, Lolium perrene-based treatment (LP), Lolium multiforium-based treatment (LM) and Lolium perenne- Trifolium repens -based treatment (LTF). In separate experiments, slurry from dairy cows fed LM was amended with AFLG and pine bark at concentrations of 25, 50, 75 and 100 g/l and stored under anaerobic conditions for 16 days. The highest and lowest excretions of N, P and K were observed in LM and LP treatments, respectively. Increasing dietary N improved K and N retention in milk and, consequently increased milk urea nitrogen (MUN) and N excretion (P < 0.05). The concentrations of AFLG affected N and P retention in manure (P < 0.05). The highest retention in total Kjeldahl nitrogen (TKN) of the initial was 42% AFLG at 25g/l inclusion rate. Ammonium nitrogen (AMN) concentration increased significantly due to the interactive effect of AFLG inclusion rate and time. Pine bark powder significantly improved N and P retention in manure at all concentrations. The retention in TKN was higher (P < 0.05) at 25g/l pine bark powder than other concentrations. The interaction effect of inclusion rate and time increased iii AMN (P < 0.05). Dietary treatments significantly affected nutrient excretion, and AFLG and pine bark considerably improved N retention in stored slurry. Findings from the filed trial suggest the need for more attention on managing dietary nutrients in the post-rainy and cool-dry season when growth of pasture influenced choice of dietary treatments that led to high nutrient excretion. Field simulation of the additives to determine their efficacy and environmental hazards was recommended.

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5

Nash, David. "Phosphorus transfer from land to water in pasture-based grazing systems /." Connect to thesis, 2002. http://eprints.unimelb.edu.au/archive/00000752.

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6

au, k. pearce@murdoch edu, and Kelly L. Pearce. "Carcass and eating quality of sheep grazing saltbush based saline pasture systems." Murdoch University, 2006. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20070516.95025.

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Forage halophytes such as saltbush (Atriplex spp) are being widely used to revegetate Australian saline land and can also provide a medium quality fodder source. There is widespread anecdotal evidence that sheep grazing on saltbush are leaner, tastier and juicer. This thesis investigated the potential to produce a high quality carcass with improved eating quality from grazing sheep on saltbush on saline land. The first experimental chapter in this thesis details an animal house experiment investigating the carcass, eating and wool quality and physiological responses of sheep ingesting a 60:40 dried saltbush (Atriplex nummularia):barley grain (S+B), ration verses a 33:25:42 lupin grain:barley grain:oaten hay ration (Control, C) for 10 weeks prior to commercial slaughter (Chapter 4). Subsequently, two field experiments were conducted to examine the effects of grazing saltbush on saline land compared to dry senesced pasture on carcass and eating quality of lambs (Goomalling 2003) and hoggets (Wickepin 2004) (both chapter 6) for 14 weeks. Both chapters demonstrated that the ingestion of saltbush resulted in significantly less fat and in the 2 field experiments the ingestion of saltbush resulted in more lean on the carcass compared to sheep grazing a stubble/pasture (control) ration. These are positive findings for processors as costs of fat denudation are high so the lower the fat content and for farmers because less fat is deposited on the carcass per unit of liveweight gain. The decreased deposition of fat was attributed to the higher protein:energy ratio available for production, secondary compounds in saltbush and lower circulating insulin and higher growth hormone of the S+B fed sheep compared to the control fed sheep. Further work is needed to determine if these beneficial improvements in carcass composition can be achieved without compromising animal production. The long term grazing of saltbush did not result in commercially desirable hot carcass weights unless the sheep were supplemented with a high energy source such as barley. The low growth rates are attributed to a decreased availability of energy substrates, low feed intake and increased energy output of sheep fed high salt diets. The low energy intake of the S+B fed sheep also resulted in an a significantly lower percentage of unsaturated fat and unchanged levels of saturated fat in the fat depots compared to the C treatment. Consumer taste tests conducted on meat from experiments in both chapter 4 and 6 indicated no difference between the treatments for any of the eating quality traits assessed. This can be considered a positive result as sheep can be finished on saltbush without any detriment to eating quality. High vitamin E levels in the meat may have also prevented the development of rancid flavours and aroma. It can be speculated that saltbush does not impart beneficial flavour and aroma volatiles as previously thought; instead the high vitamin E levels inhibit off-flavour and aroma development compared to meat from sheep grazed on dry pasture. The long term ingestion of saltbush also resulted in significantly lower urine specific gravity (USG), muscle dry matter and higher urine weights suggesting that the saltbush fed sheep had a better hydration status compared to control fed sheep. However, this finding did not correspond with higher hot carcass weight or dressing percentages. The increases in muscle fluid content of the saltbush fed sheep were attributed to changes in body composition. The saltbush fed sheep had a higher lean and lower fat content which corresponded with a greater body fluid content as found in the animal house study. Under conditions where the body composition of sheep remains the same, the use of short term strategic feeding of components of saltbush was investigated (mimicked in the form of salt and betaine) to reduce dehydration and subsequent reductions in carcass weight and dressing percentages (Chapter 7). Salt and or betaine were fed for 1 week either prior to a 48 h period of water deprivation or prior to 48 h commercial slaughter process where water was available in lairage from 24-48 h. Under both scenarios the diets did not result in improved dressing percentages, hot carcass weights, muscle dry matter or muscle weights. The ingestion of high salt diet prior to slaughter, did increase fluid retention in the extracellular spaces prior to slaughter however by 48 h both groups were at a similar physiological and therefore similar hydration status. Therefore similar levels of fluid were present in the muscles and no difference in carcass weight or dressing percentage could be expected. An important observation from the second experiment was that the high salt group drunk more water than the low salt fed sheep but the low salt group consumed fluid in lairage also. The low salt fed sheep may have been encouraged to drink water after observing the frequent drinking patterns of the high salt group. This thesis has also shown that saltbush contains high levels of vitamin E (á-tocopherol) (193 mg/kg dry matter). As a result the concentration of á-tocopherol in plasma, liver and muscle of the saltbush fed sheep was elevated compared to those grazing dry pasture. The high muscle concentrations of vitamin E in the saltbush-grazed sheep resulted in improved meat colour stability. The high vitamin E levels did not influence the drip and cooking loss of the meat despite a decrease in the muscle dry matter of the meat. The browning of meat and increased drip loss results in large losses to the meat industry due to value deterioration at the supermarket. There is also great potential for the high vitamin E content in saltbush to be used for the prevention of nutritional myopathy instead of using expensive and labour intensive synthetic supplements. In conclusion, this thesis has provided an insight into the carcass and eating quality of sheep grazed on saltbush based saline pasture systems. The most significant findings were that

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7

Fore, Steven R. "Confinement vs. pasture : an economic and environmental comparison of swine production systems /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1136078011&sid=17&Fmt=2&clientId=1509&RQT=309&VName=PQD.

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8

Pearce, Kelly Lynne. "Carcass and eating quality of sheep grazing saltbush based saline pasture systems /." Access via Murdoch University Digital Theses Project, 2006. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20070516.95025.

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9

Haile, Solomon Ghebremussie. "Soil carbon sequestration and stabilization in tree-based pasture systems in Florida." [Gainesville, Fla.] : University of Florida, 2007. http://purl.fcla.edu/fcla/etd/UFE0021415.

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10

Pearce, Kelly L. "Carcass and eating quality of sheep grazing saltbush based saline pasture systems." Thesis, Pearce, Kelly L. (2006) Carcass and eating quality of sheep grazing saltbush based saline pasture systems. PhD thesis, Murdoch University, 2006. https://researchrepository.murdoch.edu.au/id/eprint/252/.

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Abstract:

Forage halophytes such as saltbush (Atriplex spp) are being widely used to revegetate Australian saline land and can also provide a medium quality fodder source. There is widespread anecdotal evidence that sheep grazing on saltbush are leaner, tastier and juicer. This thesis investigated the potential to produce a high quality carcass with improved eating quality from grazing sheep on saltbush on saline land. The first experimental chapter in this thesis details an animal house experiment investigating the carcass, eating and wool quality and physiological responses of sheep ingesting a 60:40 dried saltbush (Atriplex nummularia):barley grain (S+B), ration verses a 33:25:42 lupin grain:barley grain:oaten hay ration (Control, C) for 10 weeks prior to commercial slaughter (Chapter 4). Subsequently, two field experiments were conducted to examine the effects of grazing saltbush on saline land compared to dry senesced pasture on carcass and eating quality of lambs (Goomalling 2003) and hoggets (Wickepin 2004) (both chapter 6) for 14 weeks. Both chapters demonstrated that the ingestion of saltbush resulted in significantly less fat and in the 2 field experiments the ingestion of saltbush resulted in more lean on the carcass compared to sheep grazing a stubble/pasture (control) ration. These are positive findings for processors as costs of fat denudation are high so the lower the fat content and for farmers because less fat is deposited on the carcass per unit of liveweight gain. The decreased deposition of fat was attributed to the higher protein:energy ratio available for production, secondary compounds in saltbush and lower circulating insulin and higher growth hormone of the S+B fed sheep compared to the control fed sheep. Further work is needed to determine if these beneficial improvements in carcass composition can be achieved without compromising animal production. The long term grazing of saltbush did not result in commercially desirable hot carcass weights unless the sheep were supplemented with a high energy source such as barley. The low growth rates are attributed to a decreased availability of energy substrates, low feed intake and increased energy output of sheep fed high salt diets. The low energy intake of the S+B fed sheep also resulted in an a significantly lower percentage of unsaturated fat and unchanged levels of saturated fat in the fat depots compared to the C treatment. Consumer taste tests conducted on meat from experiments in both chapter 4 and 6 indicated no difference between the treatments for any of the eating quality traits assessed. This can be considered a positive result as sheep can be finished on saltbush without any detriment to eating quality. High vitamin E levels in the meat may have also prevented the development of rancid flavours and aroma. It can be speculated that saltbush does not impart beneficial flavour and aroma volatiles as previously thought; instead the high vitamin E levels inhibit off-flavour and aroma development compared to meat from sheep grazed on dry pasture. The long term ingestion of saltbush also resulted in significantly lower urine specific gravity (USG), muscle dry matter and higher urine weights suggesting that the saltbush fed sheep had a better hydration status compared to control fed sheep. However, this finding did not correspond with higher hot carcass weight or dressing percentages. The increases in muscle fluid content of the saltbush fed sheep were attributed to changes in body composition. The saltbush fed sheep had a higher lean and lower fat content which corresponded with a greater body fluid content as found in the animal house study. Under conditions where the body composition of sheep remains the same, the use of short term strategic feeding of components of saltbush was investigated (mimicked in the form of salt and betaine) to reduce dehydration and subsequent reductions in carcass weight and dressing percentages (Chapter 7). Salt and or betaine were fed for 1 week either prior to a 48 h period of water deprivation or prior to 48 h commercial slaughter process where water was available in lairage from 24-48 h. Under both scenarios the diets did not result in improved dressing percentages, hot carcass weights, muscle dry matter or muscle weights. The ingestion of high salt diet prior to slaughter, did increase fluid retention in the extracellular spaces prior to slaughter however by 48 h both groups were at a similar physiological and therefore similar hydration status. Therefore similar levels of fluid were present in the muscles and no difference in carcass weight or dressing percentage could be expected. An important observation from the second experiment was that the high salt group drunk more water than the low salt fed sheep but the low salt group consumed fluid in lairage also. The low salt fed sheep may have been encouraged to drink water after observing the frequent drinking patterns of the high salt group. This thesis has also shown that saltbush contains high levels of vitamin E (alpha-tocopherol) (193 mg/kg dry matter). As a result the concentration of alpha-tocopherol in plasma, liver and muscle of the saltbush fed sheep was elevated compared to those grazing dry pasture. The high muscle concentrations of vitamin E in the saltbush-grazed sheep resulted in improved meat colour stability. The high vitamin E levels did not influence the drip and cooking loss of the meat despite a decrease in the muscle dry matter of the meat. The browning of meat and increased drip loss results in large losses to the meat industry due to value deterioration at the supermarket. There is also great potential for the high vitamin E content in saltbush to be used for the prevention of nutritional myopathy instead of using expensive and labour intensive synthetic supplements. In conclusion, this thesis has provided an insight into the carcass and eating quality of sheep grazed on saltbush based saline pasture systems. The most significant findings were that ingesting saltbush can reduce the carcass fat content, improve meat colour stability and not result in any detriment to eating quality. A potentially useful way to incorporate these results into an Australian farming system may be to use saltbush on a short term basis, not for the length of period grazed in this thesis. The short term use of saltbush should provide sufficient grazing time for an elevation of vitamin E levels in the muscle to improve meat colour stability, increase the amount of lean and decrease fat levels of a carcass all without changing eating quality and decreasing liveweight. Further work is needed to ensure that these benefits can be achieved without compromising animal production. The opportunity to utilise saltbush to produce leaner carcasses with better colour stability may encourage farmers to consider previously unproductive land planted to saltbush to be a highly useful enterprise.

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11

Pearce, Kelly L. "Carcass and eating quality of sheep grazing saltbush based saline pasture systems." Pearce, Kelly L. (2006) Carcass and eating quality of sheep grazing saltbush based saline pasture systems. PhD thesis, Murdoch University, 2006. http://researchrepository.murdoch.edu.au/252/.

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Abstract:

Forage halophytes such as saltbush (Atriplex spp) are being widely used to revegetate Australian saline land and can also provide a medium quality fodder source. There is widespread anecdotal evidence that sheep grazing on saltbush are leaner, tastier and juicer. This thesis investigated the potential to produce a high quality carcass with improved eating quality from grazing sheep on saltbush on saline land. The first experimental chapter in this thesis details an animal house experiment investigating the carcass, eating and wool quality and physiological responses of sheep ingesting a 60:40 dried saltbush (Atriplex nummularia):barley grain (S+B), ration verses a 33:25:42 lupin grain:barley grain:oaten hay ration (Control, C) for 10 weeks prior to commercial slaughter (Chapter 4). Subsequently, two field experiments were conducted to examine the effects of grazing saltbush on saline land compared to dry senesced pasture on carcass and eating quality of lambs (Goomalling 2003) and hoggets (Wickepin 2004) (both chapter 6) for 14 weeks. Both chapters demonstrated that the ingestion of saltbush resulted in significantly less fat and in the 2 field experiments the ingestion of saltbush resulted in more lean on the carcass compared to sheep grazing a stubble/pasture (control) ration. These are positive findings for processors as costs of fat denudation are high so the lower the fat content and for farmers because less fat is deposited on the carcass per unit of liveweight gain. The decreased deposition of fat was attributed to the higher protein:energy ratio available for production, secondary compounds in saltbush and lower circulating insulin and higher growth hormone of the S+B fed sheep compared to the control fed sheep. Further work is needed to determine if these beneficial improvements in carcass composition can be achieved without compromising animal production. The long term grazing of saltbush did not result in commercially desirable hot carcass weights unless the sheep were supplemented with a high energy source such as barley. The low growth rates are attributed to a decreased availability of energy substrates, low feed intake and increased energy output of sheep fed high salt diets. The low energy intake of the S+B fed sheep also resulted in an a significantly lower percentage of unsaturated fat and unchanged levels of saturated fat in the fat depots compared to the C treatment. Consumer taste tests conducted on meat from experiments in both chapter 4 and 6 indicated no difference between the treatments for any of the eating quality traits assessed. This can be considered a positive result as sheep can be finished on saltbush without any detriment to eating quality. High vitamin E levels in the meat may have also prevented the development of rancid flavours and aroma. It can be speculated that saltbush does not impart beneficial flavour and aroma volatiles as previously thought; instead the high vitamin E levels inhibit off-flavour and aroma development compared to meat from sheep grazed on dry pasture. The long term ingestion of saltbush also resulted in significantly lower urine specific gravity (USG), muscle dry matter and higher urine weights suggesting that the saltbush fed sheep had a better hydration status compared to control fed sheep. However, this finding did not correspond with higher hot carcass weight or dressing percentages. The increases in muscle fluid content of the saltbush fed sheep were attributed to changes in body composition. The saltbush fed sheep had a higher lean and lower fat content which corresponded with a greater body fluid content as found in the animal house study. Under conditions where the body composition of sheep remains the same, the use of short term strategic feeding of components of saltbush was investigated (mimicked in the form of salt and betaine) to reduce dehydration and subsequent reductions in carcass weight and dressing percentages (Chapter 7). Salt and or betaine were fed for 1 week either prior to a 48 h period of water deprivation or prior to 48 h commercial slaughter process where water was available in lairage from 24-48 h. Under both scenarios the diets did not result in improved dressing percentages, hot carcass weights, muscle dry matter or muscle weights. The ingestion of high salt diet prior to slaughter, did increase fluid retention in the extracellular spaces prior to slaughter however by 48 h both groups were at a similar physiological and therefore similar hydration status. Therefore similar levels of fluid were present in the muscles and no difference in carcass weight or dressing percentage could be expected. An important observation from the second experiment was that the high salt group drunk more water than the low salt fed sheep but the low salt group consumed fluid in lairage also. The low salt fed sheep may have been encouraged to drink water after observing the frequent drinking patterns of the high salt group. This thesis has also shown that saltbush contains high levels of vitamin E (alpha-tocopherol) (193 mg/kg dry matter). As a result the concentration of alpha-tocopherol in plasma, liver and muscle of the saltbush fed sheep was elevated compared to those grazing dry pasture. The high muscle concentrations of vitamin E in the saltbush-grazed sheep resulted in improved meat colour stability. The high vitamin E levels did not influence the drip and cooking loss of the meat despite a decrease in the muscle dry matter of the meat. The browning of meat and increased drip loss results in large losses to the meat industry due to value deterioration at the supermarket. There is also great potential for the high vitamin E content in saltbush to be used for the prevention of nutritional myopathy instead of using expensive and labour intensive synthetic supplements. In conclusion, this thesis has provided an insight into the carcass and eating quality of sheep grazed on saltbush based saline pasture systems. The most significant findings were that ingesting saltbush can reduce the carcass fat content, improve meat colour stability and not result in any detriment to eating quality. A potentially useful way to incorporate these results into an Australian farming system may be to use saltbush on a short term basis, not for the length of period grazed in this thesis. The short term use of saltbush should provide sufficient grazing time for an elevation of vitamin E levels in the muscle to improve meat colour stability, increase the amount of lean and decrease fat levels of a carcass all without changing eating quality and decreasing liveweight. Further work is needed to ensure that these benefits can be achieved without compromising animal production. The opportunity to utilise saltbush to produce leaner carcasses with better colour stability may encourage farmers to consider previously unproductive land planted to saltbush to be a highly useful enterprise.

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12

Karki, Uma Goodman Mary Schmitt. "Southern-pine silvopasture systems forage characteristics, soil quality, and landscape utilization by cattle /." Auburn, Ala, 2008. http://hdl.handle.net/10415/1409.

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13

White, Sharon. "Investigation of Pasture and Confinement Dairy Feeding Systems Using Jersey and Holstein Cattle." NCSU, 2000. http://www.lib.ncsu.edu/theses/available/etd-20000414-220827.

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Today, dairy farmers in the U.S. are faced with the challenge of reducing the cost of producing milk. Milk prices have risen very little in the past decade, while the cost of producing milk has risen steadily. In North Carolina alone, dairy farm numbers have dropped more than 30% in the last ten years, and the trend is expected to continue. Dairy farmers have been forced to increase their profitability to stay in business. In addition, farmers have been forced to comply with stricter environmental regulations. Over the past few years, interest has been shown in intensive management rotational grazing systems. This four-year comparison trial was designed to compare the milk production, herd health, reproductive performance, and environmental impacts of pasture-based and confinement feeding systems using Holstein and Jersey cattle for the Mid-Atlantic region. The project had both Spring and Fall calving herds with breeding via artificial insemination in 75-day periods. Each seasonal herd replicate had 36 cows on pasture and 36 cows in the confinement group. Similar numbers of Holsteins and Jerseys were included in each year. Paddocks grazed comprised 29 ha of cool and warm season pasture species in 37 paddocks for year-round grazing. Pasture-fed cows received variable amounts of grain and baled silage as needed depending upon pasture availability. Confinement cows were housed in a covered freestall barn with access to an exercise lot and received a total mixed ration with corn silage as the primary forage. Confinement cows produced significantly more milk than pasture-fed cows, both for total lactation and average daily production. Reproductive performance of the two treatments did not differ with an overall 75-day pregnancy rate of 68%. Jerseys in both systems did have higher percentages of cows inseminated (96.5%), conception rate (59.6%), and 75-day pregnancy rate (78%) compared to Holsteins (86%, 49%, 57.9% respectively). The percentage of cows infected with at least one case of clinical mastitis was higher in the confinement herd than the pasture-fed herd (43% vs. 24%) with Holsteins higher than Jerseys (41% vs. 26%). Interactions of breed and feeding system and average somatic cell count scores were not significantly different. Pasture-fed cows had lower average body condition scores than confinement cows, ranging from 0.2 to 0.6 points lower on a 5-point scale.In a short-term trial, intake measurements were taken from pasture-fed Holsteins and Jerseys consuming a grain supplement. This supplement was similar to those that were fed to the pasture-fed cows during the four-year trial. It was determined that Jerseys could consume as much as Holsteins at three different feeding levels (6.8, 4.5, and 2.3 kg/cow per feeding). This experiment showed that in certain time frames, Jersey cattle can consume equal amounts of supplements compared to Holsteins. Therefore in mixed groups Jerseys can consume relatively more supplemental energy relative to body size and milk production compared the Holsteins. In another short-term trial using cows from a spring season replicate, milk samples were obtained from pasture-fed and confinement-fed cattle and analyzed for fatty acid composition. The pasture grazed was a warm-season pasture, while the confinement-fed cattle consumed a corn-silage based TMR. The major fatty acid of interest was conjugated linoleic acid (CLA), which has been shown to be a potent anticarcinogen. Concentrations of CLA were 80% higher in pasture-fed cattle compared to the confinement-fed cattle. In addition concentrations of CLA were higher in Holsteins compared to Jerseys. To study the distribution of manure in a pasture-based system, pastured cows were observed for several 24-h periods. Data included: (1) times and location of all feces and urine events from eight cows, observed while in the pasture, feed area, milking parlor or in transit; and (2) all urine and feces events on pasture for all 36 cows each grazing period. The locations of urine and feces events were surveyed, mapped and analyzed. Percentages of the manure events in each area were highly correlated with time spent in each area (r= .99). Feces and urine (estimated at .12 m2 and .36 m2, respectively) from six observational periods covered 10% of the total paddock. Within 30 m2 of the portable waterer and gate, concentrations of feces and urine from the warm season observations were significantly greater than concentrations during the cool season observations. Manure on pasture was relatively evenly distributed over multiple grazing periods with the exception of the area around the water tank during summer grazings. These experiments showed that when compared to confinement-fed cattle, pasture-fed cattle produced less milk, produced more conjugated linoleic acid, had less mastitis and had lower body condition scores, while reproductive performance did not differ between the two groups. Jerseys had less mastitis, produced less conjugated linoleic acid, and performed better reproductively when compared to Holstein cattle. In addition, pasture-fed Jersey cattle can consume as much supplemental grain in certain time frames as pasture-fed Holstein cattle. Manure distribution on a pasture-based system is highly correlated with time spent in an area and is fairly evenly distributed over the paddock area over multiple grazing periods except for the area around the water tank during heat stress temperatures.

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14

White, Sharon Lea. "Investigation of pasture and confinement dairy feeding systems using Jersey and Holstein cattle." Raleigh, NC : North Carolina State University, 2000. http://www.lib.ncsu.edu/etd/public/etd-15171027310041171/etd.pdf.

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15

Bailey, Neal J. Kallenbach Robert L. "Comparison of three tall fescue-based stocker systems." Diss., Columbia, Mo. : University of Missouri--Columbia, 2009. http://hdl.handle.net/10355/6130.

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The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on Feb. 11, 2010). Thesis advisor: Dr. Robert L. Kallenbach. Vita. Includes bibliographical references.

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16

Batalha, Camila Delveaux Araujo. "Grazing strategies, animal performance and environmental sustainability in intensive pasture-based milk production systems." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/11/11139/tde-15032019-125835/.

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In Brazilian livestock, and its diverse ways of production, the management of grazing animals is known as the lowest return on investment on land use opportunities. Nevertheless, among different types of milk production systems, it is noted that the use of pasture grazing is a common feature between them. Thus, to achieve profitability and maintain system sustainability, the identification of the most adequate and efficient pasture management practices, can maximize production per cow and production per unit area. The low efficiency of this method of production, also classifies the national livestock as the major source of environmental pollution due the emission of pollutants, such as greenhouse gases and nitrogen. The adoption of pasture management techniques respecting forage physiological limits and increasing digestibility of nutrients, can reduce the excretion of nutrients and the production of methane per kilo of milk produced on the environment. The objectives of this thesis were to investigate metabolic variables, greenhouse gas emissions and animal performance for dairy cows grazing elephant grass subjected to rotational stocking strategies. Chapter 1: In this study was to evaluate two strategies of grazing management: pre-grazing targets of 95% versus maximum canopy light interception (LI). In intensive pasture-based milk production systems, the management based on LI95% allows lactating cows to have access to pastures with lower proportion of stems, with higher proportions of young leaves better chemical composition and perform an efficient grazing with lower forage losses. Therefore, the LI95% pasture management strategy results in higher energy intake, higher milk production per cow, higher stocking rates of pasture and higher milk yield per area. Also, the strategy allows the decrease of methane emissions per net energy intake when comparing to management based on LIMax. However, dietary N use efficiency did not increase with this management practice. Chapter 2: The objective of the second study was to evaluate the effects of paddock allocation time (a.m. vs. p.m.) on milk production, ruminal variables and efficiency of N use of mid-lactation dairy cows. In intensive pasture-based milk production systems, allocating cows on new paddocks on p.m. time has no effect on forage intake and milk production of grazing mid-lactation cows. However, the higher content of nonstructural carbohydrate of forage from p.m. pastures increases the yield of microbial protein, decreases milk urea nitrogen and tends to increase the yields of milk protein and milk casein compared to a.m. pastures. Throughout this thesis there were an improvement on nutritive value of forage adopting LI95% as a pre- grazing target and forage grazed at p.m. Therefore, the time of allocation on paddock should be used along with LI95% as fine-tune in intensive pasture-based milk production systems.
No Brasil, a produção animal em pastagens é reconhecida por ser uma atividade pouco competitiva frente a outras oportunidades de uso da terra. Embora sejam inúmeros os tipos de sistemas de produção de leite no Brasil, nota-se que a utilização de pastagens é característica comum. Assim, a identificação de práticas adequadas e eficientes de manejo do pastejo contribuirá com aumento da produção por vaca e por unidade de área, além de contribuir para a sustentabilidade do sistema. A baixa eficiência do uso dos recursos naturais tem classificado a pecuária nacional como uma importante fonte de poluição ambiental devido à emissão de poluentes, como gases de efeito estufa e excreção de nitrogênio. A adoção de técnicas de manejo de pastagens respeitando os limites fisiológicos da forrageira e aumentando sua digestibilidade, podem reduzir a produção de metano por quilo de leite produzido no ambiente e a excreção de nutrientes. Os objetivos desta tese foram investigar variáveis metabólicas e desempenho animal de vacas leiteiras em capim-elefante cv. cameroon submetido a estratégias de pastejo rotativo. Capítulo 1: Neste estudo foram avaliadas duas estratégias de manejo de pastejo: meta de pré-pastejo de 95% versus máxima interceptação luminosa (IL). Em sistemas intensivos de produção de leite à pasto, o manejo baseado no IL95% permite que vacas tenham acesso a pastos com maior relação folha: colmo, menores perdas de forragem, resultando em uma forragem com melhor composição química. Os animais pastejando forragem com IL95% tiveram maior consumo de matéria seca e energia, com maior produção de leite por vaca e taxa de lotação resultando em maior produção de leite por área. Além disso, a estratégia permite a diminuição das emissões de metano por consumo de energia líquida quando comparado a máxima IL. No entanto, a eficiência do uso de N não aumentou com essa prática de manejo. Capítulo 2: O objetivo do segundo estudo foi avaliar os efeitos do período de início pastejo (a.m. ou. p.m.) na produção de leite, variáveis ruminais e eficiência de uso de N de vacas leiteiras no terço médio da lactação. Em sistemas intensivos de produção de leite à pasto, o pastejo de novos piquetes no período da tarde não teve efeito sobre o consumo de forragem e produção de leite de vacas no terço médio da lactação. No entanto, o maior teor de carboidratos não fibrosos da forragem ao final do dia possibilitou o aumento da síntese de proteína microbiana, redução do nitrogênio uréico no leite e apresentou tendência para aumento da produção de proteína e caseína do leite em comparação à vacas que iniciaram o pastejo no período da manhã. Ao longo dos estudos desta tese houve uma melhora no valor nutritivo da forragem adotando IL95% e da forragem pastejada no período da tarde. Assim, o pastejo no período da tarde deve ser adotado juntamente com IL95% como ajuste fino em sistemas intensivos de produção de leite à base de pasto.

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17

Doole, Graeme John. "Value of perennial pasture phases in dryland agricultural systems of the eastern-central wheat belt of Western Australia." University of Western Australia. School of Agricultural and Resource Economics, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0213.

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Over the past thirty years, price relativities and technological development have motivated an increase in the area of land allocated to cropping, as opposed to pasture production, throughout the central wheat belt of Western Australia. Nevertheless, reducing the proportion of pasture in these rotations has challenged the future productivity of farming systems in this area. First, the frequent application of selective herbicides for weed control in extended cropping rotations has promoted the development of herbicide resistance in a number of major agricultural weeds. Second, the primary use of annual plants has promoted the development of soil salinisation by allowing a significant proportion of rainfall to recharge saline water tables. The inclusion of perennial pasture phases between extended periods of cropping may mitigate or delay these constraints to production through (a) allowing the use of costeffective forms of non-selective weed control, and (b) through creating a buffer of dry soil that absorbs leakage occurring beneath subsequent crops. This study consequently explores the value of including perennial pasture phases in dryland agricultural systems in the eastern-central wheat belt of Western Australia, accounting for benefits related to herbicide resistance and water table management. A novel computational algorithm for the solution of multiple-phase optimal control problems is developed and used to conduct a conceptual analysis of the value of lucerne (Medicago sativa L.) pasture for managing annual ryegrass (Lolium rigidum Gaudin), the primary weed in wheat belt cropping systems. The competitiveness and fecundity of annual ryegrass provide strong economic incentives to maintain a low weed population, irrespective of herbicide-resistance status. Consequently, the ineffectiveness of selective herbicides primarily reduces the profitability of cropping by motivating the adoption of more costly non-selective forms of weed control. The inclusion of lucerne in land-use rotations is only optimal in the presence of severe herbicide resistance given (a) the low efficiency of alternative weed-management practices available during the pasture phase, relative to selective-herbicide application; (b) the significant cost of establishing this perennial pasture; and (c) the high relative profitability of cereal production in the absence of resistance. The value of lucerne, relative to annual pastures, for weed management is explored in greater detail through the use of compressed annealing to optimise a sophisticated simulation model. The profitability of candidate rotations is also manipulated to account for the long-term production losses accruing to the recharge of saline groundwaters that occurs beneath them. Sequences incorporating lucerne are only more profitable than those that include annual pasture at the standard set of parameter values if (a) annual ryegrass is resistant to all selective herbicides, (b) the water table is so shallow (approximately less than 3.5 m deep) that frequent rotation with perennials is required to avert soil salinisation, or (c) sheep production is highly profitable. The value of perennial pasture is sufficient under these circumstances to overcome its high establishment cost. Consistent with intuition, these benefits are reinforced by lower discount rates and higher rates of leakage occurring beneath annual-based systems. Formulation of an effective communication strategy to report these results to producers is justified given the complexity involved in determining the true magnitude of these intertemporal benefits through alternative means, such as field trials.

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Sangha, Kamaljit Kaur, and Kamaljit kaur@jcu edu au. "Evaluation of the effects of tree clearing over time on soil properties, pasture composition and productivity." Central Queensland University. School of Biological and Environmental Sciences, 2003. http://library-resources.cqu.edu.au./thesis/adt-QCQU/public/adt-QCQU20060921.115258.

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Tree clearing is practised for greater beef production and hence monetary gains from grazing systems of central Queensland. The high rates of clearing in the past and even recently (577, 000 ha/yr during 1999-2001) were mainly to develop land for pastures. The sustainability of cleared pasture systems over the long-term is questioned. Three major types of tree communities i.e. Eucalyptus populnea F. Muell., E. melanophloia F. Muell. and Acacia harpophylla F. Muell. ex. Benth. were selected on one property in central Queensland to quantify the impacts of clearing on pasture production and composition, and soil properties. The impacts were measured over time-since-clearing (recent (<5 years), medium (11-13years) and old (>30 years)) in unreplicated cleared pastures in comparison to their replicated uncleared/intact woodland pastures of each tree community. Measures of pasture above-ground biomass production on a single property over time-sinceclearing in cleared systems showed that gains were not sustained over the long-term. The difference in response to clearing between tree communities was evident and important to support the future policy decisions. The impact of clearing on soil properties (physicochemical and biological) was confirmed, and explained the lesser availability of nutrients with time of clearing in cleared pastures. The changes in some soil properties underscored the associated risks and changes in ecosystem functions due to clearing. Less litter was produced at cleared than uncleared pastures, but nutrient release was faster at cleared compared to uncleared systems. The overall effect of clearing in terms of pasture and litter production, and major soil parameters were analysed using multivariate analyses.

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Cooke, Andrew. "The management of UK pasture-fed beef production systems and impacts on dung and disease." Thesis, University of Bristol, 2018. http://hdl.handle.net/1983/1d9548c6-dc7c-4e33-952c-9d008862ca42.

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This thesis places dung firmly at the centre of livestock farming. It tests the overarching hypothesis that intentional management of dung as a critical resource on-farm has multiple benefits that improve the resilience of beef production systems. Dung is a primary resource in beef production systems. This importance of dung as an organic fertiliser that recycles nutrients in agricultural systems is widely recognised and understood. The connection between disease, dung and its management through diet choice for beef cattle has received far less attention. In this study, the cattle diet, both intake and forage management, significantly influenced the rate of bulk and biochemical (fibre fractions, protein, lipids, carbohydrates, organic matter, ash and micronutrients) dung degradation over 84 days under three forage management treatments on the North Wyke Farm Platform. Site-specific factors were the primary drivers of bulk dung degradation; 70% of degradation was driven by field site and 4% by dung type. Non-target impacts of anthelmintics pose a risk to dung fauna that moderate dung degradation. A multiple-regression model predicted that targeted selective treatments (TST) created refugia for dung-breeding fly Scathophaga stercoraria and that proportions of treated cattle (55%) was more influential than effective dung drug concentrations (13%). Effective TST programmes rely on practical diagnostic tools. A non-invasive protocol was developed for the quantification of immuno-markers (immunoglobulins and lactoferrin) in dung for gastrointestinal health assessment. The anecdotal benefits of increasingly popular 'mob grazing' were supported by case studies of factors including pasture performance, reduced gastrointestinal nematode (GIN) burden, and soil organic matter content over a grazing season in a UK-wide study. The conclusion of this multidisciplinary study is that dung management has a critical role to play in a systems-level understanding of beef production and that optimisation relies on a quantitative understanding of the relationships between wider biological processes on farms.

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20

Sounness, Marcus Neil. "Alternative grazing systems and pasture types for the South West of Western Australia : a bio-economic analysis." University of Western Australia. School of Agricultural and Resource Economics, 2005. http://theses.library.uwa.edu.au/adt-WU2005.0054.

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Alternative grazing systems and pasture types for wool production in the south west of Western Australia were analysed using bio-economic modelling techniques in order to determine their relative productivity and profitability. After reviewing the experimental and modelling literature on perennial pastures and grazing systems, seven case studies of farmers were conducted in order to investigate the practical application of innovative grazing systems and use of perennial pastures. Together these case studies provided information for identifying relevant variables and for calibrating the modelling work which followed. The core of the work lies in a bio-economic model for investigating the comparative value of the three grazing systems and two pasture families mentioned above. A baseline scenario using currently available and reliable scientific data provides baseline results, after which a number of sensitivity analyses provide further insights using variations of four key parameters: persistence, heterogeneity, water soluble carbohydrates, and increased losses. Results show that perennial pastures are in the studied region more profitable than annual pastures. Under current baseline conditions, continuous grazing with perennial pastures is the most profitable enterprise, but this superiority is not robust under parameter variations defined by other scenarios. The more robust solution in terms of enterprise profitability is cell grazing with perennial pastures. The results indicate that intensive grazing systems such as cell grazing have the potential to substantially increase the profitability of grazing operations on perennial pasture. This result is an encouraging one in light of its implications for water uptake and salinity control. It means that economics and land care can go hand in hand, rather than be competitive. It is to be noted that it is the choice of the grazing system in combination with the pasture species, rather then the pasture species itself, that allows for such complementarity between economics and sustainable land use. This research shows that if farmers adopt practices such as cell grazing they may be able to increase the area that they can profitably plant to perennial pasture thus reducing the impacts of dryland salinity. This finding is consistent with the findings of the case studies where the farmers perceived that, provided grazing was planned, increasing the intensity of their grazing management and the perenniallity of their pastures would result in an increase in the profitability of their grazing operation. As a result this research helps to bridge a gap which has existed in this area of research, between the results of scientific research and those reported in practice.

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Rodrigues, Ana Raquel Martinho da Silva Felizardo. "Management practices and soil quality patterns in evergreen oak woodlands (montado)." Doctoral thesis, ISA/UL, 2019. http://hdl.handle.net/10400.5/18325.

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Doutoramento em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia / UL
The sustainability of evergreen oak woodlands (montado) in Portugal is currently threatened in large areas, mainly due to limited tree recruitment constrains and soil degradation. It is therefore urgent to develop sustainable management options which enhance montado productivity, ensuring their long-term viability and all ecosystem services. The present study aimed specifically to evaluate trends in soil quality changes, associated with management practices currently followed in montado. Different montado areas, corresponding to different soil types and land use histories, with different management options, including sowed and natural pasture systems, and different stocking rates and grazer species, were considered; also, the specific influence of the tree cover on the soil characteristics was investigated. The soil quality of study areas was assessed by evaluating physical, chemical and biochemical soil properties. Carbon and the main nutrient fluxes were also evaluated, assessing GHG emissions and nutrient leaching. Results enabled the assessment of the benefits associated with the establishment of improved pastures, namely in soil hydrological conditions, nutrient availability and soil organic matter status, which was particularly enhanced in areas under the tree cover influence. Nevertheless, factors associated with the soil type (texture) and livestock management (stocking rate) might have strong influence on the extent and nature of such benefits. Pasture management influence over soil carbon and nutrient fluxes were found negligible, despite disturbance may occur. Scattered trees, in the montado, promote the creation of islands of improved physical conditions and soil fertility, where the organic carbon accumulation is strongly enhanced. Trees undoubtedly improve soil quality, enhance the soil resistance to face degradation threats, and contribute to carbon sequestration. This potential should be taken into account for policy and management decisions, at both local and regional scales
N/A

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22

Parra, Amanda Silva [UNESP]. "Greenhouse gas balance in the conversion from extensive pasture to other agricultural systems in Andean region of Colombia." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/126562.

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Made available in DSpace on 2015-08-20T17:10:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-04-08. Added 1 bitstream(s) on 2015-08-20T17:26:59Z : No. of bitstreams: 1 000842997_20200414.pdf: 86943 bytes, checksum: 7412fff38136c54a3f28ead5328f0880 (MD5)
O desafio do setor agrícola é reduzir as emissões e aumentar a produção de alimentos, tendo em conta os aspectos ambientais. Na zona andina da Colômbia, há uma crescente necessidade de se desenvolver técnicas de mitigação de GEE (gases de efeito estufa) associados à produção de leite. Este trabalho considera as emissões de GEE e os potenciais sumidouros de carbono associados aos cenários de produção de leite na zona andina da Colômbia. Os cenários considerados foram: agricultura convencional de Pennisetum clandestinum em rotação com batatas (PRP), pastagens melhoradas de Lolium multiflorum (IP) e sistema silvipastoril de Pennisetum clandestinum em consórcio com Acacia decurrens e Trifolium repens (SPS). Com base nas metodologias do IPCC (2006) e considerando-se um ciclo de produção de 6 anos, o balanço anual das emissões compreende as fontes agrícolas e o consumo de gasolina relacionadas com as principais fases de produção agrícola, e o potencial de acúmulo de C no solo e a fixação de C na biomassa em todos os cenários estudados. Menores emissões de GEE foram estimados no cenário de PRP (3.864 kg CO2eq ha-1 ano-1), porém apresenta uma menor produtividade de leite. As maiores emissões de GEE foram observadas no cenário IP (7.711 kg CO2eq ha-1 ano-1), que apresentou uma maior produtividade de leite e um potencial considerável para o acúmulo de C no solo, que poderia ajudar na compensação das emissões. No cenário SPS, que tem uma produtividade de leite próximo de IP, apresentou o maior potencial para compensar as emissões de GEE (4.878 kg CO2eq ha-1 ano-1) devido ao acúmulo de C solo e a fixação de C na biomassa em árvores
The challenge of agricultural sector is to reduce emissions and increase food production, taking into account environmental aspects. In Andean zone of Colombia, there is a growing need to develop GHG (greenhouse gas) mitigation techniques associated to milk production. This work focuses on the GHG emissions and potential sinks associated to milk production scenarios in the Andean zone of Colombia. The scenarios considered were: conventional agriculture of Pennisetum clandestinum in rotation with potatoes (PRP), improved pastures of Lolium multiflorum (IP) and silvopastoral system of Pennisetum clandestinum in consortium with Acacia decurrens and Trifolium repens (SPS). Based on the IPCC (2006) methodologies, the annual emission balance for a 6-year production cycle included agricultural sources and gasoline consumption related to the main agricultural phases in field, and the potential for soil C accumulation and biomass C fixation in all studied scenarios. Lower GHG emissions were estimated in PRP scenario (3,864 kg CO2eq ha-1 yr-1), but this presents the lower milk productivity. The higher GHG emissions were observed in IP scenario (7,711 kg CO2eq ha-1 yr-1), which presented the highest milk productivity and a considerable potential for soil C accumulation, that could help into the offset of its emissions. But SPS scenario, which has a milk productivity close to IP, presented the highest potential to offset GHG emission (4,878 kg CO2eq ha-1 yr-1) due to soil C accumulation plus biomass C fixation in trees

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Parra, Amanda Silva. "Greenhouse gas balance in the conversion from extensive pasture to other agricultural systems in Andean region of Colombia /." Jaboticabal, 2015. http://hdl.handle.net/11449/126562.

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Orientador: Newton La Scala Junior
Coorientador: Eduardo Barretto de Figueiredo
Banca: Débora Marcondes Bastos Pereira Milori
Banca: Marcelo Valadares Galdos
Banca: Gener Tadeu Pereira
Banca: Glauco de Souza Rolim
Resumo: O desafio do setor agrícola é reduzir as emissões e aumentar a produção de alimentos, tendo em conta os aspectos ambientais. Na zona andina da Colômbia, há uma crescente necessidade de se desenvolver técnicas de mitigação de GEE (gases de efeito estufa) associados à produção de leite. Este trabalho considera as emissões de GEE e os potenciais sumidouros de carbono associados aos cenários de produção de leite na zona andina da Colômbia. Os cenários considerados foram: agricultura convencional de Pennisetum clandestinum em rotação com batatas (PRP), pastagens melhoradas de Lolium multiflorum (IP) e sistema silvipastoril de Pennisetum clandestinum em consórcio com Acacia decurrens e Trifolium repens (SPS). Com base nas metodologias do IPCC (2006) e considerando-se um ciclo de produção de 6 anos, o balanço anual das emissões compreende as fontes agrícolas e o consumo de gasolina relacionadas com as principais fases de produção agrícola, e o potencial de acúmulo de C no solo e a fixação de C na biomassa em todos os cenários estudados. Menores emissões de GEE foram estimados no cenário de PRP (3.864 kg CO2eq ha-1 ano-1), porém apresenta uma menor produtividade de leite. As maiores emissões de GEE foram observadas no cenário IP (7.711 kg CO2eq ha-1 ano-1), que apresentou uma maior produtividade de leite e um potencial considerável para o acúmulo de C no solo, que poderia ajudar na compensação das emissões. No cenário SPS, que tem uma produtividade de leite próximo de IP, apresentou o maior potencial para compensar as emissões de GEE (4.878 kg CO2eq ha-1 ano-1) devido ao acúmulo de C solo e a fixação de C na biomassa em árvores
Abstract: The challenge of agricultural sector is to reduce emissions and increase food production, taking into account environmental aspects. In Andean zone of Colombia, there is a growing need to develop GHG (greenhouse gas) mitigation techniques associated to milk production. This work focuses on the GHG emissions and potential sinks associated to milk production scenarios in the Andean zone of Colombia. The scenarios considered were: conventional agriculture of Pennisetum clandestinum in rotation with potatoes (PRP), improved pastures of Lolium multiflorum (IP) and silvopastoral system of Pennisetum clandestinum in consortium with Acacia decurrens and Trifolium repens (SPS). Based on the IPCC (2006) methodologies, the annual emission balance for a 6-year production cycle included agricultural sources and gasoline consumption related to the main agricultural phases in field, and the potential for soil C accumulation and biomass C fixation in all studied scenarios. Lower GHG emissions were estimated in PRP scenario (3,864 kg CO2eq ha-1 yr-1), but this presents the lower milk productivity. The higher GHG emissions were observed in IP scenario (7,711 kg CO2eq ha-1 yr-1), which presented the highest milk productivity and a considerable potential for soil C accumulation, that could help into the offset of its emissions. But SPS scenario, which has a milk productivity close to IP, presented the highest potential to offset GHG emission (4,878 kg CO2eq ha-1 yr-1) due to soil C accumulation plus biomass C fixation in trees
Arvores.
Doutor

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Salam, Kawsar Parveen. "Improving the fit of new annual pasture legumes in Western Australian farming systems: experience from Cadiz and Casbah." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/1953.

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Annual pasture legumes (APLs) are important in Western Australian farming systems, with subterranean clovers and annual medics being dominant. However, due to potential environmental, economic and biological constraints of these species, alternatives have been sought, with a second generation of new species being introduced since 1991. Despite the views of researchers about the advantages in WA conditions of the newly released annual pasture legumes over traditional pastures, there is a perception by some industry decision makers that their level of adoption has been lower than expected. However, there was not a good method for evaluating the level of adoption. The aim of this study was therefore to enhance understanding of how to improve the fit of new annual pasture legumes in Western Australian farming systems, taking two pastures, French serradella (Ornithopus sativus) cv. Cadiz and Biserrula (Biserrula Pelecinus) cv. Casbah (Hereafter, will be referred to as Cadiz and Casbah.), as examples.The objectives of the study were implemented in four steps. In step one, a framework, built on a three-tier hierarchy (broad adoption potential or BAP, broad attainable adoption potential or BAAP, and maximum attainable adoption potential or MAAP) was developed based on the agro-ecological suitability of the annual pasture legumes. BAP was calculated from the amount of suitable land in terms of soil and rainfall requirements for an APL. The BAAP was calculated by multiplying BAP with two coefficients related to the proportion of cropping area within a geographic region, and the crop-pasture ratio within the cropping area. The MAAP was calculated by multiplying BAAP with a coefficient related to the certainty of a successful pasture-growing season. This coefficient was derived from a Microsoft-Excell®-based Climate Reliability Calculator particularly developed for this study. The broad attainable adoption potentials (BAAP) for Cadiz and Casbah were calculated as 1.67 M ha and 1.18 M ha, respectively. These figures were about 81% less than the calculated broad adoption potential (BAP). The maximum attainable adoption potentials (MAAP) for Cadiz and Casbah in Western Australian cropping-belt were calculated as 0.99 and 0.89 M ha, respectively.In step two, a survey was conducted to understand the salient issues that farmers consider in relation to adopting a new annual pasture legume for their farming systems. An open-ended question was used for them for the attributes they desired for their ‘dream’ pasture. Questions were also asked about their experiences of strengths and weaknesses for Cadiz and Casbah. Responses were analysed using the principles of ‘grounded theory’. Furthermore, based on farmers’ perceptions, an APL-characteristics framework was developed for Western Australia. The framework consisted of six attributes of a pasture. They are, in order of importance calculated from the percent of farmers responses: superiority in establishment and growth (79%), ability in supplying quality feed (49%), improved potential in controlling weeds (38%), adaptability in broader agro-ecological horizon (36%), tolerant to major insect-pests (20%), and inexpensive (15%). Many farmers desired a combination of these components rather than just a single component. The two test APLs, Cadiz and Casbah, were compared under this framework based on the responses of the farmers.In the third step, using farmers’ perceptions of the salient attributes and other variables, an empirical model was developed to predict the likely adoption of any annual pasture legume in Western Australian farming systems. The model consisted of the product of two components, AAAR and TRMAP. The AAAR was the averaged annual adoption rate (as the percentage of all pastures grown in Western Australia) of the APL. TRMAP is the time, in years, required to reach the maximum adoption potential of the APL. The AAAR was related to the agronomic characteristics of the APL (the three most wanted characteristics by farmers, i.e. establishment and growth, feed supply and quality and weed control) and an ‘inter-competition’ factor, whereas the TRMAP was attributed to its scope of adaptation. Both AAAR and TRAMP were essentially regression models. The model performed well when tested independently for Cadiz and Casbah using inputs from two different sources, i.e. breeders and farmers. In the final step, the model was applied to predict the adoption of Cadiz and Casbah using inputs from breeders and farmers in order to understand what level of adoption breeders would have expected and to what extent farmers would support the breeders’ view. Results showed that breeders were expecting Cadiz and Casbah would be adopted in about 32% and 22% of their potential areas (MAAP) compared to the achieved adoption of 23% for Cadiz and 20% for Casbah, respectively.On the other hand, model output using farmers’ evaluation scores indicated that the adoption would be 20% for Cadiz and 19% for Casbah, which is much closer to the achieved adoption level. The difference between breeders’ expectation and farmers’ evaluation on adoption potential of Cadiz and Casbah was due to differences in evaluation scores provided by the two groups on different pasture characteristics in relation to establishment and growth, weed control and feed supply and quality. Some of the pasture characteristics desired by the farmers, such as reliable regeneration, seed settings, easy establishment, general vigor, good chemical tolerance, good feed supply and quality, suitable for wide range of soils, good insect tolerance are not commonly present when Cadiz and Casbah are grown in the farming environments.Two issues for further consideration if the adoption levels of Cadiz and Casbah were to be increased in WA farming systems are: decreasing the knowledge gap among farmers on tactical management of APLs though extension, and improved pasture characteristics through the breeding/selection process. Furthermore, this study designed a system consisting of three major components: the maximum attainable adoption potential (MAAP), the annual pasture legume characteristics framework (APL-characteristics for Western Australia) and achievable adoption potential (AAP). This system acts as a common platform - where breeders, farmers, extension specialists and policy makers could work as a team towards improving the fit of annual pasture legumes, and potentially other crops if the required supporting information was collected, in Western Australian farming systems.

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Whistance, Lindsay Kay. "The Eliminative Behaviour of Dairy Cows at Pasture and in Different Housing Systems and the Potential for Adjustment through Training." Thesis, Harper Adams University College, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485328.

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Experiments were conducted to investigate cattle behaviour patterns at the time of elimination, whether this is affected by housing type or yield status or if behaviour can be manipulated to improve cleanliness levels during the housing period. Study 1 compared the eliminative behaviour of four groups of cows within and between a straw yard and a cubicle system. Intentional avoidance, where a cow moved away from excreta and where the behaviour that she engaged in pre-defaecation was resumed without her engaging in a different activity, was highest in cows in the straw yard. Cows demonstrating no avoidance of excreta, in which case they either remained lying, or lay do'wn without moving away, were mostly in the cubicle system or in the straw yard if they were high yielding. In study 2, grazing cows showed higher levels of movement away from fresh excreta and avoidance of excreta occurred throughout in all cows. The predominant behaviour was standing to eliminate and then moving forward. Walking whilst eliminating occurred when cows were simultaneously highly motivated to perform a second activity, such as catching up with herd mates or going to drink. Caives (study 3) and heifers (study 4) were trained to recognise where they defaecated or urinated using clicker training, with correct behaviour being reinforced with sweetened milk or concentrates. Five calves were removed from training with health problems but all of the remaining study animals (calves = 5; heifers = 13) successfully associated the offering of a reward with an act of elimination. Shaping the behaviour to only eliminate on concrete was not possible for animals of either age and appeared to be linked to the ineffectiveness of substrate type as a cue in training and to individual differences in behaviour patterns. It is concluded that cows show avoidance of faeces in both grazing and housed environments, particularly the former. They can be trained to recognise when they eliminate but it was not possible to train them to void in a concreted area of a building, which could be more easily cleaned than their bedded area.

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Kabore, Bertin. "Investigations into soil nutrient and change in soil physical characteristics under complementary forage rotation in comparison to pasture systems for dairy cows." University of Sydney, 2009. http://hdl.handle.net/2123/5355.

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Master of Science in Veterinary Science
A investigation into soil nutrient and the change soil physical properties was carried out for three pasture systems for dairy cows; the complementary forage rotation (CFR) which comprised of brassica (Brassica napus )/clover (Trifolium resupinatum ) and maize (Zea mays) capable of achieving more than 40 t/ha, the typical intensive pasture (PI) with kikuyu grass (Penisetum clandestinum) over-sown with ryegrass ( Lolium multiflorum ) and the extensive system (PE); on two soil types (brown chromosol and black vertisol) . The study demonstrated that the CFR system was capable of doubling its yield by using similar fertilizers (N, P and K) and water inputs compared to these of the PI system resulting of greater nutrients (N and K) and water use efficiencies. Overall, the nutrient lost through runoff water was very limited for two intensive systems and nearly nil for PE system. Also similar trends were observed for soil physical properties in the intensive systems except for the topsoil (0-10 cm) where light acidification (P= 0.04) was recorded in the CFR probably due to the soil works before the maize sowing.

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Kaboré, Bertin. "Investigations into soil nutrient and change in soil physical characteristics under complementary forage rotation in comparision to pasture systems for dairy cows." Connect to full text, 2008. http://ses.library.usyd.edu.au/handle/2123/5355.

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Thesis (Ph. D.)--University of Sydney, 2009.
Title from title screen (viewed December, 2009) Submitted in fulfilment of the requirements for the degree of Master of Veterinary Science to the Faculty of Veterinary Science. Degree awarded 2009 ; thesis submitted 2008. Includes bibliographical references. Also available in print form.

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Ballesteros, Raúl David Guevara. "Enteric Methane and Nitrogen Emissions in Beef Cattle Grazing a Tannin-Containing Legume Relative to Feedlot and Traditional Pasture-Based Production Systems." DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7666.

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Beef cattle production is highly criticized because of the high use of land and water resources, and by the pollution (e.g., the gas methane in a cow’s breath and nitrogen in urine) produced by cows fed in feedlots. In contrast to feedlots diets and grasses, some plants (e.g., legumes) contain bioactive compounds (condensed tannins) that reduce pollution and enhance animal nutrition. In my research, I observed that cows grazing a tannin-containing legume (birdsfoot trefoil; BFT) had methane emissions similar to cows fed a feedlot ration with comparable weight gains. Cows in the BFT treatment gained more weight than cows grazing grass (meadow brome) or a legume without tannins (cicer milkvetch). Additionally, I estimated the potential areas in the state of Utah than can sustain birdsfoot trefoil production, with 412,250 ha distributed mostly in the Box elder, Cache, Millard and Sanpete counties. Thus, feeding tannin-containing legumes to cows is a viable alternative to feedlot rations, with greater levels of productivity than other pasture-based systems, which can lead to a more sustainable production of beef.

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Sasanti, Babalwa. "The effect of Fleckvieh crossbreeding in dairy cattle on the conjugated linoleic acid content of milk produced in intensive and pasture-fed systems." Thesis, Cape Peninsula University of Technology, 2015. http://hdl.handle.net/20.500.11838/2004.

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Thesis submitted in fulfilment of the requirements for the degree of Magister Technologiae: Agriculture in the Faculty of Applied Sciences at the Cape Peninsula University of Technology
Conjugated linoleic acid (CLA), a fatty acid (FA) present in the meat and milk of ruminant animals, is considered a functional nutrient for humans. The interest in CLA is attributed to its many health benefits, such as having anti-carcinogenic, anti-atherogenic, anti-diabetic and anti-adipogenic effects. Dairy products are a rich natural source of CLA, and preliminary research indicates that the levels in milk can vary based on cattle breed and feeding system. The Fleckvieh is a popular dual-purpose breed recently introduced to the Western Cape. It is used in crossbreeding programs with Holstein and Jersey herds to increase fertility and beef production. Holstein and Jersey cattle are the two most common South African dairy breeds, but little information is available on the effect of crossbreeding on FA content and CLA levels in the milk. The primary objective of this study was to compare milk FA composition and CLA content of these two dairy breeds and their respective Fleckvieh crosses. A second objective was to investigate the effect of lactation stage on CLA levels. Jersey (J) and Fleckvieh x Jersey (F×J) cows were kept in a pasture-based system (PBS) for the duration of the study. Holstein (H) and Fleckvieh x Holstein (F×H) cows were housed in a feedlot system and fed a total mixed ration (TMR) for the duration of the study. The FA and CLA content of feeds from these two feeding systems were also analysed and compared. All cows used in the study were housed at the Elsenburg Research Farm of the Western Cape Department of Agriculture. Milk samples were collected every 35 days from the cows in each feeding group, starting 10 days after calving. Samples were kept in a freezer at -20 °C until laboratory analyses. The total number of milk samples collected was 1044. The milk FA composition and CLA in particular were determined by gas chromatography. Differences between groups were statistically analysed by two-way repeated measures of analysis of variance (ANOVA). Results show that milk CLA levels are higher in Fleckvieh-crossbred cows when compared to purebred cows. The higher CLA content of milk from Fleckvieh crossbred cows demonstrates the feasibility of using Fleckvieh bulls in South African crossbreeding programs, and are also an indication that genetic selection for increased CLA content is possible. The analysis of lactation stage showed that milk CLA is higher during late lactation. A comparison of feed samples from the two feeding systems revealed that pasture feeding resulted in higher omega-3 FA in milk. Key words: Conjugated linoleic acid, milk fatty acids profile, diet, breed, health benefits, Fleckvieh, Holstein, Jersey, diet, pasture based system, total mixed ration system,

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Schaak, Henning [Verfasser], Oliver [Akademischer Betreuer] Mußhoff, Oliver [Gutachter] Mußhoff, Achim [Gutachter] Spiller, and Ulf [Gutachter] Liebe. "Agricultural and societal perspectives on pasture-based livestock production systems in Germany / Henning Schaak ; Gutachter: Oliver Mußhoff, Achim Spiller, Ulf Liebe ; Betreuer: Oliver Mußhoff." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://d-nb.info/1201548950/34.

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Schaak, Henning [Verfasser], Oliver [Akademischer Betreuer] Mußhoff, Oliver Gutachter] Mußhoff, Achim [Gutachter] [Spiller, and Ulf [Gutachter] Liebe. "Agricultural and societal perspectives on pasture-based livestock production systems in Germany / Henning Schaak ; Gutachter: Oliver Mußhoff, Achim Spiller, Ulf Liebe ; Betreuer: Oliver Mußhoff." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://nbn-resolving.de/urn:nbn:de:gbv:7-21.11130/00-1735-0000-0005-12C5-8-7.

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32

Werner, Jessica [Verfasser], and Matthias [Akademischer Betreuer] Schick. "Measuring grazing behaviour of dairy cows : validation of sensor technologies and assessing application potential in intensive pasture-based milk production systems / Jessica Werner ; Betreuer: Matthias Schick." Hohenheim : Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim, 2019. http://d-nb.info/1182423558/34.

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33

McDonald, Kathi. "Variation in morphology, salinity and waterlogging tolerance and resource allocation in strawberry clover (Trifolium fragiferum L.) : implications for its use in mildly saline soils in southern Australian farming systems." University of Western Australia. School of Plant Biology, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0105.

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[Truncated abstract] In southern Australian farming systems the replacement of deep-rooted perennial native vegetation with shallow-rooted annual crops and pastures has resulted in rising groundwater tables and an increased incidence of dryland salinity. It has been suggested that to address this issue by restoring hydrological balance, large areas of agricultural land need to be vegetated with perennial plants. One of the most agriculturally productive ways to do this is to introduce perennial pastures, both into upslope groundwater

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Weber, Daniel Adam. "GRASSLAND SUSTAINABILITY IN KENTUCKY: CASE STUDIES QUANTIFYING THE EFFECTS OF CLIMATE CHANGE ON SLUG HERBIVORY IN PASTURES AND DIFFERENT HOME LAWN SYSTEMS ON TURF GREENHOUSE GAS EMISSIONS." UKnowledge, 2014. http://uknowledge.uky.edu/pss_etds/39.

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Grasslands comprise the greatest biome by land area, are sensitive to environmental factors affected by climate change, and can impact future climate change through their ability to store and release greenhouse gasses (GHGs). I performed two studies: 1) evaluated the effects of increased temperature and precipitation on slug herbivory/abundance and pasture forage production; 2) quantified different homeowner lawn system effects on soil-to-atmosphere GHG emissions. Climate change will likely affect pasture forage production, with implications for slug herbivory and abundance. I found little evidence that slugs have or will have significant effects on pasture production or plant community. Warming altered the abundance of slugs and modified seasonal trends, increasing slug abundance in spring/winter and reducing it in late-summer/fall, through both direct effects and changes in plant community and forage quality. Home lawns vary in levels of management, influencing the exchange of GHGs. I quantified the effects of three common home lawn systems of central Kentucky on GHG emissions, but found no significant differences in CO2, N2O, and NH3 fluxes. My research suggests that slug herbivory is not a dominant ecological process in Kentucky pastures and that common home lawn systems have similar soil-to-atmosphere GHG emissions.

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Santos, Mario Jorge Campos dos. "Avaliação econômica de quatro modelos agroflorestais em áreas degradadas por pastagens na Amazônia ocidental." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/11/11142/tde-08112002-134456/.

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O presente estudo teve como objetivo avaliar a viabilidade econômica de quatro sistemas agroflorestais em área com pastagem degradada na Amazônia Ocidental. A área escolhida para o desenvolvimento desta pesquisa está localizada na Estação Experimental da EMBRAPA/CPAA (Empresa Brasileira de Pesquisas Agropecuárias - Centro de Pesquisas Agroflorestais da Amazônia Ocidental) no Distrito Agropecuário da SUFRAMA - DAS, Km 54 da BR-174 (Manaus-Boa Vista- Brasil), em áreas de terra firme. Os modelos agroflorestais analisados foram implantados seguindo delineamento experimental em blocos casualizados, com 5 tratamentos, 3 repetições e a pastagem abandonada como testemunha, em parcelas de 3.000 m 2 (60m x 50m), com uma área total de 4,5 ha. Os tratamentos foram distribuídos da seguinte forma: ASP-1 (Sistema Agrossilvipastoril altos insumos); SP2 (Sistema Agrossilvipastoril baixos insumos); AS1 (Sistema Agrossilvicultural baixos insumos com palmeiras); AS2 (Sistema agrossilvicultural baixos insumos multiestrato) e pastagem abandonada (testemunha). Houve aplicação de insumos para correção de acidez e fertilidade do solo. A avaliação econômica dos sistemas agroflorestais analisados baseou-se no cálculo do valor presente líquido dos respectivos fluxos de caixa constituídos a partir da presuposição que os mesmos podem ser repetidos perpetuamente. Os resultados obtidos, mostraram que os modelos agroflorestais utilizados são economicamente viáveis, indicando que este tipo de atividade pode contribuir para a regeneração de áreas com nível de degradação semelhante ao observado no estudo de caso e para a sobrevivência econômica dos agricultores da região.
Agroforestry systems have been considered to recover degraded areas, so as to increase the agricultural and forestry productivity and diminish the economic risk to the farmer. Four agroforestry models were introduced into a degraded pasture and abandoned areas located in one of the Experimental Station (Suframa-DAS) of the Embrapa/CPAA ( Empresa brasileira de pesquisas agropecuaria/ Centro de Pesquisas Agroflorestais da Amazônia Ocidental), at Km 54 BR-174 (Manaus-Boa Vista). This study was a randomized complete block design with 5 agroforestry models and three replicates for each model and an abandoned pasture area as the control. The parcel area measured 3,000m 2 (60m X 50m) for a total of 4.5 ha. Trataments were: ASP1 (Agrosilvipastoral systems - higt output); ASP2 (Agrosilvipastoral systems - low input); AS1 (Agrosilvicultural systems - low output with palmers tree); AS2 (Agrosilvicultural systems - low output multistrata). Fertilizers were to correct for the effects of soil acidity and soil fertility. Economic evaluations were based on the following economical criteria: Net Present Value and Land Expectation Value. Results showed that the agroforestry models were economically acceptable indicating that this kind of agroforestry activity generates income and could be used as an alternative way to recorver degraded areas in the Amazon. Agroforestry system AS2 produced the best results among the systems studied. All four systems were efficient at reestablishing the vegetative productivity. It produced agricultural benefits to the farmer and the utilized species play a important role in the land maintenance and protection against fire use and erosion. More research utilizing SAFs are required for this region to emphasize the economic benefits of the systems.

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36

Peden, Robert L., and n/a. "Pastoralism and the transformation of the rangelands of the South Island of New Zealand 1841 to 1912 : Mt Peel Station, a case study." University of Otago. Department of History, 2007. http://adt.otago.ac.nz./public/adt-NZDU20071204.155512.

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The transformation of the rangelands of the South Island of New Zealand during the pastoral era fits into the wider international context of European expansion into the 'new' world. European settlers displaced native peoples, introduced 'old' world animals and plants, and imposed a capitalist system that converted local resources into international commodities. In New Zealand the orthodox explanation of the pastoral impact on the rangelands claims that pastoralists introduced an unsustainable system of land use to the region. The pastoralists� indiscriminate burning practices and overstocking with sheep opened up the country to invasion by rabbits. Burning and overgrazing by sheep and rabbits stripped the natural fertility of the soils and left the country depleted, eroded, and overwhelmed by pests and weeds. This thesis sets out to test those claims. It explores burning, the stocking of the rangelands with sheep and the impact of rabbits in detail. It also examines other land management practices, as well as sheep breeding, to see what impact they had on the landscape. The timeframe is set between 1841, when formal British settlement was established in the South Island, and 1912, by which time most of the great estates and stations had been broken up into smaller runs and farms. The thesis uses station diaries, memoirs, contemporary newspapers and farming journals to assess what happened on the ground during the pastoral era. In particular, the thesis uses Mt Peel Station as a case study to examine the intensification in land use that took place between 1841 and 1912, in order to explain the transformation of the landscape and to answer the questions: what happened, how did it happened and why did it happened as it did? These sources illustrate that the pastoral era was characterised by innovation. Pastoralists had access to technical and scientific information from around the world. Some conducted their own experiments to improve the productivity of the land and their stock. There was also a learning process involved in adapting their methods to fit the local rangeland environments. They were not simply rapacious capitalists out to strip the wealth from the land for their own personal gain; indeed, many pastoralists set out to establish viable and sustainable enterprises. The thesis argues that the rangelands consisted of a variety of landscapes and climates. Differences in resource endowments had a considerable influence in shaping the environmental outcomes on different stations. Aridity and rabbits were two key factors in the depletion of the vegetation and the degradation of the landscape in the rangelands. Runs in semi-arid districts that were overwhelmed by rabbits suffered long-term damage. In districts where rainfall was more reliable stations that had been overrun by rabbits recovered remarkably quickly. Stations like Mt Peel, that were largely unaffected by the first rabbit plague, were able to maintain and even increase their productivity up to the time they were subdivided. The orthodox analysis of the transformation of the rangelands in the pastoral era does not account for these differences in outcomes.

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37

Roberts, Sean David Kerth Christopher R. "Forage quality, animal performance, and carcass traits of steers finished on winter annual ryegrass (Lolium multiflorum Lam.) pasture with varying levels of corn supplementation." Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Fall/Thesis/ROBERTS_SEAN_9.pdf.

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38

Machado, Paulo Roberto. "PASTAGENS DE COASTCROSS-1 CONSORCIADA COM LEGUMINOSAS SOB PASTEJO." Universidade Federal de Santa Maria, 2013. http://repositorio.ufsm.br/handle/1/10829.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The objective of this research was to evaluate of three pasture-based systems with bermudagrass (BG) + 200 kg of N/ha; BG + 100 kg of N/ha and common vetch; BG + 100 kg of N/ha + forage peanut. The experiment was carried out from May 2011 to may 2012. Holstein cows receiving 4 kg-daily complementary concentrate feed were used in the evaluation. The actual mean value of forage on offer was 7.2 kg of dry matter/100 kg live weight. Herbage mass, botanical and structural composition, daily dry matter accumulation rate, forage production, disappearance of forage mass and stocking rate were evaluated. Nine grazing cycles were performed during the experimental period (365 days). The mean value of forage production and stocking rate were 21.05; 21.8 and 16.1 t/ha; 5.1; 5.3 and 4.5 animal units/ha/day for respective pasture systems. Superior result were found on BG + 100 kg of N/ha + common vetch and BG + 200 kg of N/ha pasture systems.
Objetivou-se com essa pesquisa avaliar três sistemas forrageiros constituídos por capim bermuda (CB) + 200 kg de N/ha; CB + 100 kg de N/ha e ervilhaca comum e CB + 100 kg de N /ha + amendoim forrageiro. O experimento foi realizado entre maio de 2011 e maio de 2012. Para avaliação foram utilizadas vacas em lactação da raça Holandesa, que receberam individualmente 4 kg/dia de concentrado. A oferta de forragem foi de 7,2 kg de matéria seca /100 kg de peso vivo. Foram avaliadas a massa de forragem, a composição botânica e estrutural, a taxa de acúmulo diário de matéria seca, a produção de forragem e o desaparecimento de massa de forragem e a taxa de lotação. Durante o período experimental (365 dias) foram realizados nove ciclos de pastejo. O valor médio da produção de forragem e a taxa de lotação foram de 21,05; 21,8 e 16,1 t/ha; 5,1; 5,3 e 4,5 unidades animais/ha/dia para os respectivos sistemas forrageiros. Resultados superiores foram encontrados nos sistemas forrageiros constituídos por CB+ 100 kg de N/ha + ervilhaca comum e CB + 200 kg de N/ha.

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39

Zhang, Heping. "Water use in a poplar tree-pasture system." Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336665.

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Verdi, Paulo Henrique Peres. "Análise da viabilidade econômica de sistemas de recuperação de pastagens degradadas em solos arenosos." reponame:Repositório Institucional do FGV, 2018. http://hdl.handle.net/10438/22064.

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There is much talk about the low productivity of Brazilian cattle ranching and the enormous extent of degraded pastures that the country has, including regions of sandy soils with less agricultural potential. Public and private institutions invest in research to find alternatives on how to increase productivity and mitigate the environmental impacts caused by cattle production. The objective of this study is to analyze the economic viability of pasture recovery systems in sandy soils, considering the model of production in degraded pastures, the production model with the São Mateus integrated system, and a model considering pasture renovation and maintenance with fertilizers and correctives. From the main models, alternative scenarios have been created modifying the main variables to understand under which condition a system is economically attractive or not. The results indicate that the São Mateus integrated system is the most profitable in the proposed scenario, followed by the production model in degraded pastures. The model considering renovation of pastures on sandy soils with fertilization and maintenance of fertility resulted to be economically unfeasible.
Muito se fala sobre a baixa produtividade da pecuária de corte brasileira e a enorme extensão de pastagens degradadas que o país possui, inclusive em regiões de solos arenosos com menor potencial agropecuário. Instituições públicas e privadas investem em pesquisa para buscar alternativas de como incrementar a produtividade e mitigar os impactos ambientais causados pela produção de bovinos. O objetivo deste trabalho é analisar a viabilidade econômica de sistemas de recuperação de pastagens em solos arenosos, considerando o modelo de continuidade de produção em pastagens degradadas, o modelo de produção com o sistema iLP (integração lavoura-pecuária) São Mateus, e um modelo considerando reforma e manutenção de pastagens com fertilizantes e corretivos. A partir dos modelos principais, foram criados cenários alternativos modificando as principais variáveis para entender sob qual condição um sistema é ou não atrativo economicamente. Os resultados indicam que o sistema iLP São Mateus é o mais rentável no cenário proposto, seguido do modelo de produção em pastos degradados. A reforma de pastagens em solos arenosos com adubação e manutenção da fertilidade se mostrou economicamente inviável.

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Hafla, Aimee Nicole. "Winter cereals as a pasture-hay system in Montana." Thesis, Montana State University, 2008. http://etd.lib.montana.edu/etd/2008/hafla/HaflaA1208.pdf.

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In 2006 - 2008 \'Willow Creek\' winter wheat and \'Trical 102\' triticale were evaluated for biomass production and forage quality under grazing and hay systems in Montana. Forage cultivars of winter wheat and triticale were subjected to a single grazing event at three growth stages (vegetative, boot, or heading) in the late spring. Subsequent regrowth from each grazing event was harvested as hay. Growth of winter cereals was modeled with environmental conditions. Both cultivars reached 100% headed between accumulated growing degree day (base 5 CÂ°) 1090 and 1245 (between July 7 and 13) during the three year trial. During this period, winter cereals experienced rapid forage growth, and grew 1.4 to 2.6 cm daily and produced 87 to 248 kg ha-1 daily. In two years, triticale had superior forage biomass compared to winter wheat. Forage quality of winter cereals was excellent at the vegetative stage of growth and declined until the final forage harvest dates. At all growth stages winter wheat and triticale had similar levels of forage quality. However, the rates of digestibility of winter wheat pasture and hay were greater than those of triticale. When grazed at increasing stages of maturity, winter cereals demonstrated variable forage regrowth yield and quality. Delaying grazing until later dates coincided with hot and dry growing season conditions and limited forage regrowth potential. Regrowth of grazed cereals declined in forage quality with advancing maturity. Nitrate concentrations were high enough to concern producers with pregnant livestock grazing in spring or when grazing regrowth. Grass tetany was found to be a potential risk to lactating livestock grazing early vegetative winter cereal forage. In a whole animal digestion trial, winter wheat hay was had similar digestibility when compared to traditional grass alfalfa hay, in a sheep maintenance diet. Winter cereals can offer producers a viable option for a pasture-hay system in Montana. Maximum total biomass was a single cutting of hay at anthesis and early grain development. Therefore, it will be necessary for livestock producers to consider total biomass, availability and cost of pasture and hay, and forage quality, when using a pasture-hay system in Montana.

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Anjos, Amanda Nunes Assis dos. "PRODUTIVIDADE DO CAPIM BERMUDA EM CONSORCIADO COM LEGUMINOSAS DE CICLO HIBERNAL." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/10864.

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The objective of this research was to evaluate three grazing systems with Coastcross-1 (CC) + 100 kg N/ha/year + common vetch; CC + 100 kg N/ha/year + arrowleaf clover; and CC + 200 kg N/ha/year. The experiment was carried out from May 2013 to April 2014. Lactating Holstein cows were used in the evaluation. The grazing method was the rotative stocking, with one day of occupation. Thirteen grazing cycles were performed during the experimental period (313 days). The forage mass, botanical composition, leaf/stem ratio; daily accumulation rate, production and forage intake; grazing efficiency and stocking rate were evaluated. Experimental design was completely randomized with three treatments (grazing systems), three replicates (paddocks) in completely split-plot time (seasons). The average of forage production and stocking rate were 20.8, 17.6 and 19.7 t/ha/year; 7.0, 6.8 e 6.8 animal units/ha/day, respectively. Better results were found on CC + 100 kg of N/ha + common vech and CC + 200 kg of N/ha pasture systems. The presence of the legumes did not affect the structural composition of Coastcross-1, but implies delay in the development of this grass.
Objetivou-se com esta pesquisa avaliar três sistemas forrageiros constituídos por: Coastcross-1(CC) + ervilhaca comum + 100 kg de N/ha/ano; CC + trevo vesiculoso + 100 kg de N/ha/ano e CC + 200 kg de N/ha/ano. O experimento foi conduzido entre maio de 2013 e abril de 2014. Para avaliação foram utilizadas vacas em lactação da raça Holandesa. O método de pastejo utilizado foi o de lotação rotacionada, com um dia de ocupação. Durante o período experimental (313 dias) foram realizados treze pastejos. Foram avaliados a massa de forragem, composição botânica, relação folha/colmo; taxa de acúmulo diário, produção e consumo de foragem; eficiência de pastejo e taxa de lotação. O delineamento experimental utilizado foi o inteiramente casualizado com três tratamentos (sistemas forrageiros), três repetições (piquetes) e parcelas subdivididas no tempo (estações do ano). Os valores médios de produção de forragem e taxa de lotação foram de 20,8; 17,6 e 19,7 t/ha/ano; 7,0; 6,8 e 6,8 unidades animais/ha/dia, respectivamente. Melhores resultados foram encontrados nos sistemas forrageiros constituídos por CC + 100 kg de N/ha + ervilhaca comum e CC + 200 kg de N/ha. A presença das leguminosas não afetou a composição estrutural da Coastcross-1, mas implica em atraso no desenvolvimento dessa gramínea.

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43

Teany, Laura Ellen. "Phosphorus Losses from Simulated Dairy Mangement Intensive Grazing Forage System." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/30811.

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Dairy producers across the country are evaluating the effectiveness of management intensive grazing (MIG) systems as a means of reducing the economic pressures of confinement feeding and manure handling. Systems using MIG have been promoted as an environmentally safer way of managing nutrient balance on Center. However, little research has been conducted to evaluate how these systems affect phosphorus (P) loss from the Center through runoff and forage removal. The goal of this study was to investigate the effects of forage type and manure density on P levels in runoff from release plots that simulated a MIG dairy system. Two forage treatments were planted on runoff release plots and applied with three manure density treatments and four replications of each combination for a total of 24 plots. Orchardgrass (Dactylis glomerata) and a broad-leafed forage treatment consisting of buckhorn plantain (Plantago lanceolata), red clover (Trifolium pratense), and alfalfa (Medicago sativa) were planted on the runoff release plots in early spring. Manure densities with no manure (control), a density simulating a low stocking density (low), and a density simulating high stocking density (high) were applied to plots during grazing simulations. Six rainfall simulations were conducted over the season simulating grazing conditions when forage was removed and re-growth conditions when forage had reached its target re-growth height before re-grazing occurred. Thirty minutes of runoff was collected from the runoff release plots to determine first flush phosphorus losses from the various treatments. Mass losses of total phosphorus (TP) for manure treatments in series 1 were significant due to plot installation disturbance. No significant effect for ortho-phosphorus (ortho-P), particulate phosphorus (PP) or TP concentration or mass losses were observed for other simulation series. Significantly higher mass losses were observed in series 1 for both forage treatments, again due to installation disturbance. Seasonal mass losses for TP were significantly lower for the orchardgrass treatment. Forage mass removal over the season increased as the stands established. Orchardgrass treatments appeared to control P losses earlier in the season, while broadleaf treatments observed a steady increase in ortho-P losses up to series 5. Both mass and concentration losses of TP were controlled earlier in the season by orchardgrass, while PP showed no significant mass or concentration loss effects.
Master of Science

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44

Odhiambo, John F. "Management of the suckled post partum beef cows pasture based weaning system /." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4315.

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Thesis (M.S.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains ix, 64 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 49-60).

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45

Clinton, Peter William. "Competition for nitrogen and moisture in a Pinus radiata-pasture agroforestry system." Thesis, University of Canterbury. Forestry, 1990. http://hdl.handle.net/10092/6755.

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A 3 x 2 factorial experiment was conducted to examine the outcome and some of the competitive mechanisms between P. radiata (D. Don) and pasture for N and soil moisture. The factors examined were the monthly addition of 30 kg N/ha versus no additional N, and the manipulation of the level of pasture competition by spraying and simulated-grazing to give three levels of pasture competition. The experiment coincided with a period of severe drought which greatly increased the competition for soil moisture. Removal of pasture competition by spraying released a large amount of N into the soil mineral N pool. It also reduced overall demand for N and water because of the reduction in competition resulting in improved tree growth and greater N uptake by trees. However, it was apparent that moisture was the main limiting factor for tree growth in the plus-pasture treatments because, whilst trees did take up some of the applied N in the plus-pasture treatments, they showed no increase in growth and N uptake. A localized effect of trees on pasture dry matter production and N content occurred. Directly beneath trees and in the area predominantly occupied by tree roots competition for water and N was intense. Pasture response to N was greatest away from the tree rooting zone. Pasture appeared to compete successfully due to the nature of its root system which consists of a large biomass of very fine roots compared to the small biomass of fine pine roots in the surface soil. Competition between pasture and trees was further examined using the stable isotope 15N to trace a single 15N-labelled application of N fertilizer in spring. Recovery of 15N during the split fertilizer application program was assessed by periodic pasture harvests in the simulated-grazing treatment and by obtaining a complete balance sheet after 249 days. The dynamics of plant availability of applied 15N and retention of 15N in the soil was also followed. The recovery and retention of 15NO3- and 15NH4+ in particular were compared in the simulated-grazing treatment. Larger quantities of 15NO3- remained available to plants than 15NH4+ and 15N was still found in the KCl-extractable mineral N pool at 154 and 249 days after application. P. Radiate assimilated the same amount of 15N when added as 15NO3- or 15NH4+ in the simulated-grazing treatment but uptake into the aboveground biomass of pasture was greater for 15NO3- than for 15NH4+. However, pasture uptake of 15NO3- and 15NH4+ was not significantly different when pasture stubble and roots were include in the total recovery for all harvests. Removal of pasture competition increased the availability of 15N for the period just after application but 15N uptake by P. radiata was only doubled. There were no significant differences in 15N recovery between treatments in the 0-20 cm depth of soil; on average this was 49% of that applied. Total system recovery was 107, 92, 76, and 71% for the 15NO3-treated, 15NH4+ -treated simulated-grazing treatments, 15NH4+ -treated rank, and sprayed treatments, respectively. The loss of 15N from the system was not accounted for by leaching although this was not directly measured. In the sprayed treatment where the loss of 15N was greatest, it was thought that 15N loss may have been due to denitrification. The root systems of neighbouring trees did not overlap and midway between the trees there was apparently no competition between trees and pasture since no effect of tree roots on pasture growth and 15N uptake could be shown. Uptake by artificially-grazed pasture did not seem to reduce 15N movement into the canopy to the same extent as uptake by rank pasture. In the simulated-grazing treatment the increased cycling of N or reduced pasture root growth may have provided some benefit to tree uptake of 15N.

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46

Lasley, Peter Wallace. "Corn distillers dried grains with solubles supplementation in a pasture-based beef production system." [Ames, Iowa : Iowa State University], 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1473228.

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47

Kharrat, Maya. "Capacités adaptatives de la chèvre Baladi alimentée sur parcours en conditions semi-arides de la Békaa (Liban)." Thesis, Montpellier, SupAgro, 2010. http://www.theses.fr/2010NSAM0011/document.

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L'élevage de la chèvre « Baladi » au Liban souffre d'un problème de disponibilité alimentaire responsable des faibles performances établies de la race, du fait de sa dépendance majoritaire des zones de pâturage naturel et de la rareté des terrains fourragers ou de l'adoption du système intensif. Dans ce contexte agroclimatique particulier, cette étude se propose d'identifier la conduite optimale, à mi-chemin entre système extensif compromettant la production et la durabilité de l'élevage et système hors-sol qui ne saurait valoriser les aptitudes de la race et les parcours de la région. En effet, les conditions climatiques difficiles de la région d'étude impliquent l'insertion d'une dimension temporelle dans la conceptualisation de la conduite optimale, prenant en considération les fluctuations saisonnières non négligeables des ressources alimentaires naturelles. Comparée à la conduite extensive traditionnelle et à la complémentation largement moins adoptée, une conduite où les chèvres laitières seraient mises au pâturage durant les mois de printemps caractérisé par la prolifération des espèces végétales en vert et enfermées durant la sécheresse estivale paraît a priori adaptée aux conditions du milieu et aux objectifs zootechniques et socioéconomiques. Le cas échéant, le système intensif étant rarement prisé par les éleveurs de la région, l'efficacité des parcours à résidus agricoles ou fourragers aura également été évaluée afin de trouver un optimum zootechnique et économique. Par la suite, il a fallu mettre en place un outil d'évaluation des caractéristiques nutritives des parcours de la région d'étude, des quantités ingérées par les animaux lors du pâturage ou à l'auge et finalement de leur impact direct sur la production laitière et la satisfaction des besoins. L'évaluation des différentes conduites se reflétant dans un nombre de réponses en cours de lactation, un suivi d'analyse continu a été instauré permettant d'apprécier l'état corporel des animaux (poids, note d'état corporel, métabolites énergétiques), la production laitière (rendement, durée de lactation et composition du lait) et les performances reproductives (prolificité et croissance des chevreaux). Les capacités d'adaptation des animaux aux restrictions alimentaires dans les différentes conduites ont ainsi été testées. Ces expérimentations réalisées sur deux ans de suite ont montré que ces chèvres manifestent de réelles capacités adaptatives aux aléas alimentaires. En particulier, à chaque fois que l'alimentation le permet, l'énergie disponible est orientée préférentiellement vers la production laitière avec des rebonds relativement importants. Ces rebonds se produisent quel que soit le niveau de production laitière et pendant pratiquement toute la lactation. Parallèlement, on observe une reconstitution lente et régulière des réserves adipeuses qui s'accélère en fin de lactation à un moment où les femelles sont généralement mises à la reproduction, alors que les productions laitières baissent inexorablement. Cette thèse a donc abouti à l'acquisition de connaissances originales sur un modèle animal peu étudié caractérisé par des capacités adaptatives remarquables qui ne se manifestent pas de façon aussi marquée chez les chèvres sélectionnées des zones tempérées
Adaptives capacities of Baladi goats fed on semi-arid rangelands of Bekaa valley (Lebanon)ABSTRACTThe Lebanese Baladi goat dairy production sector suffers from a problem of food availability which is responsible of the animal's poor performances, due to its dependence towards natural rangelands and the scarcity of crop residues and forage pastures as well as of the adoption of intensive systems.In this particular agroclimatic context, this study aims to identify the optimal conduct for this goat, half-way between an extensive system where production and durability are compromised and an intense one where the aptitudes of the breed and the variety of the region's pastures are not valorized. In fact, the region's difficult climatic conditions require the insertion of a temporal dimension in the conceptualization of the optimal conduct, considering the important seasonal fluctuations of the natural feed resources. Compared to the traditional extensive conduct and to the much less adopted supplementation, a conduct where the goats were pasture driven during the spring characterized by the proliferation of green plants and kept indoors during the summer season seems a priori adapted to the local conditions and to the technical and economic objectives. However, the intensive system being rarely considered by the local farmers, the efficiency of agricultural pastures such as crop residues and forages would also have been tested in order to find an optimum between production and feasibility. Thus, an evaluation tool of the pastures' nutrition values, the quantities ingested by the animals during grazing and indoors and finally of their impact on the milk production and satisfaction of feed requirements was implemented. The evaluation of the different tested conducts were reflected on a number of physiological responses during lactation such as the animals' body reserves (body weight, body condition score, NEFA), milk production (quantities, duration and milk composition: milk fat and milk protein contents) and reproductive performances (kids' number, birth weights and growth). The animals' adaptive capacities to different food restrictions situations are hence here tested.These trials realized on two subsequent years showed that this breed demonstrates clear adaptive capacities facing feed fluctuations. A particular adaptation is the orientation of the available extra energy towards milk production with relatively important rebounds whenever allowed by refeeding. These rebounds occurred whatever the initial milk production level and during practically the whole lactation period. In parallel, we observed a slow and regular reconstitution of the body reserves which accelerates at the end of lactation, when the females are getting ready for reproduction, while the milk production suddenly breaks down. In consequent, this study has collaborated in acquiring new original information about an original animal breed characterized by special adaptive capacities which don't generally show in selected high production breeds.Kewords : Baladi goat, feeding conduct, pasture, indoors, adaptive capacities, feeding behaviour, body reserves, milk production, reproductive performances

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48

Goni, Sindisile. "Production and reproduction performance of Jersey and Fleckvieh × Jersey cows in a pasture-based system." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86433.

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Thesis (MScAgric)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Genetic selection for high milk production, type and appearance for the last 50 years has suppressed secondary traits such as reproductive performance, productive life, health and survivability in the pure milk breeds. The economic importance of these secondary traits in dairy production systems is the basis for the interest seen in crossbreeding. The problem of growth rate of heifers, cow fertility, reduced disease resistance and small body frame for beef production in Jerseys can be improved by crossing Jerseys with dual purpose breeds, such as Fleckviehs which possess a more beef potential. Against this background, this study aimed at comparing the production and reproduction of Jersey and Fleckvieh × Jersey cows in a pasture-based system. Milk recording was done according to standard milk recording procedures. Milk production (milk, fat, and protein yield) was adjusted to 305 days of lactation and corrected for age at calving. Effects of breed, parity, month and year were estimated for milk, fat and protein yield as well as fat and protein percentage using general linear models procedure. The fixed effects identified as having significant effects on milk, fat and protein yield were breed, parity and year. F×J cows produced significantly more milk than J cows (6141 ± 102 vs. 5398 ± 95 kg milk). Protein and fat yield were significantly higher in F×J (201 ± 3 and 272 ± 4 kg, respectively) than in J cows (194 ± 2 and 246 ± 3 kg, respectively). There percentages of fat and protein differed slightly between the two breeds with the Jersey recording slightly higher percentages (4.61 ± 0.04 and 3.62 ± 0.03 %, respectively) compared to the F×J cows’ percentages, which were, respectively, 4.47 ± 0.04 and 3.51 ± 0.03 %. It was concluded that F×J crossbred cows were more productive than purebred J cows probably owing to heterotic effects. Heifers were inseminated at 13 months of age and cows 40 days post-calving. Using insemination records and pregnancy check results, fertility traits were analyzed and compared between the two breeds, using analysis of variance for continuous records. Conception age was the same for both breeds resulting in a similar age at first calving. For cows, the interval from calving to first insemination was significantly shorter (P <0.001) in crossbred cows being 76.7 ± 2.2 days compared to 82.4 ± 2.5 days for purebreds. A larger proportion (P < 0.001) of 0.70 for crossbred cows was inseminated within 80 days after calving compared to 0.54 for J cows. Although the absolute number of days between calving and conception (DO) was lower for F×J cows in comparison to J cows (104.8 ± 6.8 vs. 114.8 ± 8.1days, respectively), the difference was not significant. However, the proportion of F×J cows confirmed pregnant by 100 days in milk was 0.79, which was higher (P < 0.001) than the 0.66 for J cows. Results indicate the potential of improving reproductive performance of J cows through crossing with dual-purpose breeds. The beef production of purebred J and Fleckvieh x Jersey (F×J) bull calves was compared, where bull calves were reared similarly for veal, i.e. carcass weight not exceeding 100 kg, or as steers for beef to 21 months of age. In both the veal and steer production systems, the mean birth weight were higher (P < 0.001) for crossbred in comparison to J calves and steers (33.5 ± 1.2 kg vs. 27.9 ± 1.2 kg for veal) and (33.4 ± 0.9 kg vs. 26.9 ± 0.9 kg for steers) respectively. The live weight at 6 months of age was 163.5 ± 3.9 kg for J bull calves, which was lower (P < 0.001) than that for F×J bull calves (180.6 ± 4.0 kg). The F×J bull calves had a significantly higher average daily gain (ADG) of 0.82 ± 0.02 kg/day compared to 0.73 ± 0.02 kg/day for J bulls. Marketing age differed (P < 0.001) in the veal production system with F×J and J bull calves marketed at 7.1 ± 0.1 and 6.3 ± 0.1 months, respectively. End live weight at 21 months of age was significantly higher (P < 0.001) in F×J bulls (441.4 ± 14.9 kg) than the 322.6 ± 13.4 kg in J bulls; while ADG differed (P < 0.001) between the two breeds being 0.64 ± 0.02 and 0.46 ± 0.0 kg/day in F×J and J bull calves, respectively. Crossbred steers had a significantly higher carcass of 206.5 ± 8.9 kg compared to 157.9 ± 8.6 kg for J steers. Results indicate the potential of improving beef production characteristics of the J cattle through crossbreeding.
AFRIKAANSE OPSOMMING: Genetiese seleksie vir hoë melkproduksie, tipe en voorkoms die afgelope 50 jaar het sekondêre eienskappe soos reproduksie, produktiewe lewe, gesondheid en oorlewing onderdruk in die suiwer melk rasse. Die ekonomiese belangrikheid van hierdie sekondêre eienskappe in melkproduksie stelsels is die basis vir kruisteling. Probleme soos groei tempo van verse, koei vrugbaarheid, verlaagde weerstandbiedenheid teen siektes en klein liggaam raam vir vleisproduksie in Jerseys kan verbeter word deur die kruising van Jerseys met ' n dubbele doel rasse, soos Fleckviehs wat beskik oor beter vleis potensiaal. Teen hierdie agtergrond, is hierdie studie daarop gemik om produksie en reproduksie van Jersey en Fleckvieh x Jersey koeie in 'n weiveld - gebaseerde stelsel te vergelyk. Melk opname is gedoen volgens standaard melkaantekening prosedures. Melkproduksie (melk-, veten proteïen opbrengs) was aangepas vir 305 dae van laktasie en gekorrigeer vir kalf ouderdom. ‘n Algemene lineêre model was gebruik om die effekte van ras, pariteit , maand en jaar op melk-, vet- en proteïen opbrengs sowel as vet- en proteïen persentasie te bepaal. Die vaste effekte geïdentifiseer met 'n beduidende effek op melk-, vet- en proteïen opbrengs was ras, pariteit en jaar. F × J koeie het aansienlik meer melk as J koeie (6141 ± 102 teen 5398 ± 95 kg melk) produseer . Vet opbrengs was aansienlik hoër in F × J koeie as in J koeie (272 ± 4 246 teen ± 3 kg vet). Proteïen opbrengs was ook aansienlik hoër in F × J koeie as J koeie (201 ± 3 vs 194 ± 2 kg proteïen). Vet en proteïen persentasies het geneig om effens te verskil met 'n klein effek (4.61 ± 0.04 % vet en 3.62 ± 0.03 % proteïen) vir J koeie en (4.47 ± 0.04 % vet en 3.51 ± 0.03 % proteïen) vir F × J koeie. Daar is tot die gevolgtrekking gekom dat F × J gekruisde koeie kan meer produktief wees as suiwer J koeie weens heterotiese effekte. Verse kunsmatig geïnsemineer was op 13 maande ouderdom en koeie 40 dae na- kalwing aangehou was. Met behulp van bevrugting en swangerskap rekords, is vrugbaarheid eienskappe ontleed en vergelyk tussen die twee rasse, met behulp van ontleding van variansie vir deurlopende rekords. Ouderdom van bevrugting was dieselfde vir beide rasse wat in 'n soortgelyke ouderdomsgroep was by eerste kalwing. Vir koeie was die interval van kalf tot eerste inseminasie aansienlik korter (P < 0.001) vir kruisgeteelde koeie wat 76.7 ± 2.2 dae in vergelyking met 82.4 ± 2.5 dae suiwerrasse is. ‘n Groter proporsie ( P < 0.001) van 0.70 vir gekruisteelde koeie is binne 80 dae na kalwing geïnsemineer in vergelyking met 0.54 vir J koeie. Alhoewel die absolute aantal dae tussen kalwing en opvatting (DO) laer was vir F × J koeie in vergelyking met J koeie (104.8 ± 6.8 teen 114.8 ± 8.1dae, onderskeidelik), is die verskil nie betekenisvol nie. Maar die verhouding van F × J koeie wat swanger bevestig is met 100 dae in melk was 0.79, wat hoër was (P < 0.001) is as die 0.66 vir J koeie. Resultate dui daarop dat daar potensiaal is reproduktiewe prestasie te verbeter van J koeie deur kruisteling met 'n dubbel- doel rasse. Die vleisproduksie van suiwer J en Fleckvieh x Jersey (F × J) bulkalwers vergelyk. Die bul kalwers is soortgelyk grootgemaak vir kalfsvleis, d.w.s karkas gewig mag nie 100 kg oorskry as bulkalwers nie, en as osse vir vleis tot 21 maande oud. In die kalwers- en os produksie stelsels, was die gemiddelde geboorte gewig hoër (P < 0.001) vir die kruise in vergelyking met J kalwers en osse (33.5 ± 1.2 kg teen 27.9 ± 1.2 kg vir kalwers) en (33.4 ± 0.9 kg vs . 26.9 ± 0.9 kg vir osse) onderskeidelik . Die lewendige gewig op 6 maande ouderdom was 163.5 ± 3.9 kg vir J bulkalwers en was hoër (P < 0.001) vir F × J bulkalwers 180.6 ± 4.0 kg. Die F × J bul kalwers het 'n aansienlik ‘n hoër gemiddelde daaglikse toename (GDT) van 0.82 ± 0.02 kg/dag in vergelyking met 0.73 ± 0.02 kg/dag vir J bulle. Bemarkingsouderdom verskil (P < 0.001) in die kalf produksie stelsel met F × J en J bulkalwers bemark op 7.1 ± 0.1 en 6.3 ± 0.1 maande , onderskeidelik. Finale lewendige gewig van 21 maande oud was aansienlik hoër 441.4 ± 14.9 kg in F × J bulle as 322.6 ± 13.4 kg in J bulle , terwyl GDT hoër was (P < 0.001), met 0.64 ± 0.02 kg/dag en 0.46 ± 0.0 kg/dag in F × J en J bulkalwers, onderskeidelik. Gekruisde osse het 'n aansienlik hoër karkasgewig 206.5 ± 8.9 kg in vergelyking met 157.9 ± 8.6 kg van J osse. Resultate dui daarop dat daar potensiaal is om die beesvleis produksie-eienskappe van die J beeste te verbeter d.m.v. kruisteling.

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Ruto, Christopher Kiptanui. "Lamb and wool production in an organic farming system." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3839.

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Thesis (M.S.)--West Virginia University, 2005
Title from document title page. Document formatted into pages; contains vii, 51 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 46-51).

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50

Purevjav, Tsengeg. "Incorporating condensed corn distillers solubles into an integrated pasture and drylot finishing system for feedlot steers." [Ames, Iowa : Iowa State University], 2008.

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Dissertations / Theses on the topic 'Pasture systems'

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