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Articoli di riviste sul tema "Australian merino sheep Productivity Experiments"
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Eady, SJ, PK O'Rourke e PT Connelly. "Comparison of wool production and reproductive rate of South Australian strain Merinos and locally bred Peppin Merinos in the semi-arid tropics of Queensland". Australian Journal of Experimental Agriculture 31, n. 6 (1991): 737. http://dx.doi.org/10.1071/ea9910737.
Testo completoAbstract (sommario):
Three experiments were conducted to provide information on the wool production and reproductive rates of different strains of Merino sheep, and on the role of heat tolerance in determining the productivity of sheep in north-western Queensland. The locally bred Peppin Merinos had a significantly (P<0.05) lower rectal temperature (RT) and respiratory rate (RR) under heat load than the South Australian (SA) strain Merinos. Place of birth of SA Merinos had no effect on their RT and RR. At 16 months of age the Peppin sheep produced significantly (P<0.05) less clean wool (1.55 v. 1.82 kg) and had significantly (P<0.05) lower liveweights (28.5 v. 31.6 kg) than the SA group reared in the same environment. Although differences between the groups were not always statistically significant, there was a trend for a consistent increase in wool production, fibre diameter and liveweight as the proportion of SA in the cross increased. The impact of these differences on proceeds from wool sales is discussed. At maturity the SA strain ewes were heavier (P<0.05) than their Peppin counterparts (48.4 v. 44.1 kg) and produced heavier (P<0.05) lambs at 6 weeks of age (7.0 v. 6.2 kg) and at weaning (13.9 v. 12.5 kg). Milk yield at 6 weeks post-lambing was significantly (P<0.05) greater for the SA sheep than the Peppin Merinos (303 v. 216 mL/day). Lamb survival from 6 weeks to 3 months was 64% for the SA Merinos and 45% for the Peppin Merinos, but this difference was not statistically significant. The SA strain Merinos produced more clean wool and heavier offspring than locally bred Peppin sheep and demonstrated a similar reproduction rate in the face of severe drought conditions.
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Behrendt, Karl. "Price risk exposure of Australian Merinos – is it in the bloodline?" Animal Production Science 54, n. 9 (2014): 1317. http://dx.doi.org/10.1071/an14305.
Testo completoAbstract (sommario):
Sheep producers and their advisors utilise Australian Merino bloodline trial data to guide future sheep breeding objectives and ram selection. To adequately assess the economic outcomes from different bloodlines in the decision making process, there is a need to consider the impact of wool and sheep meat price risk. Using a steady-state wether flock model that accounts for the lifetime productivity of 268 reported Merino bloodlines and stochastic dependency in weekly wool and sheep meat prices from 28 June 2005 to 10 November 2011, gross incomes per dry sheep equivalent (GI/DSE) were calculated for a weekly time step. The analysis found that across all bloodlines and market price scenarios, GI/DSE ranged between AU$13.92 and AU$67.83, with an overall mean of AU$32.60. The individual means of bloodlines across the time series ranged from AU$37.46 to AU$25.19 GI/DSE. The coefficient of variation, used as the measure of relative risk for each bloodline, ranged from 0.24 to 0.30 with a mean of 0.25. The analysis showed that a bloodlines exposure to price risk has a curvilinear relationship to fibre diameter and fleece weight. The results from a risk-reward point of view indicate that the majority of Australian Merino bloodlines are risk-inefficient. This suggests Australian sheep producers have a significant opportunity to increase net returns and reduce price risk exposure by identifying and switching to more risk-efficient bloodlines.
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LUSHNIKOV, V. P. "MEAT PRODUCTIVITY OF RAMS OBTAINED BY CROSSING VOLGOGRAD SHEEPS WITH RAMS OF DIFFERENT FOREIGN BREEDS". Sheep, goats, woolen business, n. 2 (2021): 23–25. http://dx.doi.org/10.26897/2074-0840-2021-2-23-25.
Testo completoAbstract (sommario):
The article presents the indicators of slaughter, morphological and chemical composition of lamb meat obtained from industrial crossing of Volgograd breed queens with sheep breeds: Poll Dorset, Australian meat merino, North Caucasian meat-wool, Suff olk, Ile-de-France and Merinoland.
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Lakota, E. A. "Productivity of Stavropol sheep with Australian meat merino rocks in the Volga region". Agrarian science 322, n. 2 (febbraio 2019): 42–43. http://dx.doi.org/10.32634/0869-8155-2019-322-2-42-43.
Testo completo
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Cottle, D. J., M. T. Harrison e A. Ghahramani. "Sheep greenhouse gas emission intensities under different management practices, climate zones and enterprise types". Animal Production Science 56, n. 3 (2016): 507. http://dx.doi.org/10.1071/an15327.
Testo completoAbstract (sommario):
Greenhouse gas emissions (GHG) from broadacre sheep farms constitute ~16% of Australia’s total livestock emissions. To study the diversity of Australian sheep farming enterprises a combination of modelling packages was used to calculate GHG emissions from three sheep enterprises (Merino ewe production for wool and meat, Merino-cross ewes with an emphasis on lamb production, and Merino wethers for fine wool production) at 28 sites across eight climate zones in southern Australia. GHG emissions per ha, per dry sheep equivalents and emissions intensity (EI) per tonne of clean wool or liveweight sold under different pasture management or animal breeding options (that had been previously determined in interviews with farmers) were assessed relative to baseline farms in each zone (‘Nil’ option). Increasing soil phosphorus fertility or sowing 40% of the farm area to lucerne resulted in the smallest and largest changes in GHG/dry sheep equivalents, respectively (–66%, 113%), though both of these options had little influence on EI for either clean wool or liveweight sold. Breeding ewes with greater body size or genotypes with higher fleece weight resulted in 11% and 9% reductions, respectively, in EI. Enterprises specialising in lamb production (crossbred ewes) had 89% lower EI than enterprises specialising in fine wool production (Merino wethers). Thus, sheep producers aiming for lower EI could focus more on liveweight turnoff than wool production. Emissions intensities were typically highest in cool temperate regions with high rainfall and lowest in semiarid and arid regions with low aboveground net primary productivity. Overall, animal breeding options reduced EI more than feedbase interventions.
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Lakota, E. A., e M. V. Zabelina. "An effective type of merino in the Volga region by the method of intrabreed selection". Agrarian science, n. 7-8 (24 settembre 2021): 24–27. http://dx.doi.org/10.32634/0869-8155-2021-351-7-8-24-27.
Testo completoAbstract (sommario):
The article presents experimental data on the use of intrabreed selection in order to create the most effective productive type of sheep of the Stavropol fine-wool breed. In the zone of the dry steppe of the Volga region the sheep of the Stavropol breed were improved by the meat merino of the Australian selection. Scientific and experimental research was carried out in JSC “New Life” ofNovouzensky district of the Saratov region. The crossbreeds obtained during the step-by-step crossing of Stavropol sheep with tup-producers of Australian meat merino with 1/8-blood content according to AMM by eye-measuring the degree of severity of wool and meat productivity were distributed according to productive indicators (live weight, wool shearing) to the corresponding specific types of productivity. The first group — the uterus of the wool productive type; the second — wool-meat, the third — meat-wool. Each group of sheep was assigned to tuh of meat-wool productive type. The offspring were obtained according to the selection of parental pairs: father x mother. At birth, the M-W x M-W ewe hoggs had an advantage over the W x M-Wanimals in terms of live weight by 7.47%, and over the M-W x M-W — by 1.7%. After weaning at 4.5 months, the live weight of all young animals decreased slightly. In 13.5 months, the superiority of group III over group I and II was 9.3%, 4.6%. In terms of cutting physical wool, group II yarks outperformed group I and III by 1.91 and 3.45%, while their advantage in pure wool was 13.6 and 4.11%. The longest coat was characterized by the young animals of group I, the stronger coat was in the young animals of group III. In the structure of fine-wooled sheep of the Stavropol breed of the Volga population three productive types were distinguished, which differ from each other in terms of productive indicators: wool, wool-meat and meat-wool. At the same time sheep of the Stavropol breed, bred in the dry steppe of the Volga region, to a greater extent deviate towards the wool-meat productive type, such merinos of the combined direction in the conditions of the modern economic situation are most demanded and profitable.
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Ponnampalam, E. N., D. L. Hopkins, F. R. Dunshea, D. W. Pethick, K. L. Butler e R. D. Warner. "Genotype and age effects on sheep meat production. 4. Carcass composition predicted by dual energy X-ray absorptiometry". Australian Journal of Experimental Agriculture 47, n. 10 (2007): 1172. http://dx.doi.org/10.1071/ea07008.
Testo completoAbstract (sommario):
This study compares the carcass composition of different genotypes of Australian sheep slaughtered at four ages (110, 236, 412 and 662 days of age, or 4, 8, 14 and 22 months of age). The genotypes used were Poll Dorsetgrowth × Border Leicester Merino (PDg × BLM), Poll Dorsetgrowth × Merino (PDg × M), Poll Dorsetmuscling × Merino (PDm × M), Merino × Merino (M × M) and Border Leicester × Merino (BL × M). Approximately 150 mixed sex animals were slaughtered at each age and the right sides (half carcass) were scanned by dual energy X-ray absorptiometry (DXA) for chemical lean, fat and bone mineral percentages of the carcass. Carcass lean percentage decreased (P < 0.001) across sire groups from Merino to Poll Dorset to Border Leicester at each age, while fatness increased (P < 0.001) in the opposite direction. With age, the magnitude of difference between genotypes for fatness became greater. There was a marked increase (P < 0.01) in ash mineral percentages in M × M and PDg × M genotypes relative to other genotypes in the 14- and 22-month groups. There were no differences (P > 0.1) between PDg × M and PDm × M in either chemical lean or fat percentages at any age but ash mineral percentage was higher in the PDg × M genotype at older ages (P < 0.05). This in turn led to differences in chemical lean : ash mineral content at later ages between PDg × M and PDm × M. Wethers had higher chemical lean (P < 0.05) and lower fat (P < 0.05) percentages in the carcass than ewes at all ages but ash mineral and chemical lean : ash mineral content did not differ between sexes. It was clear that the level of chemical lean or fat or ash mineral composition reached by some genotypes at one age was equivalent to that reached by other genotypes at the next measurement age. Those genotypes that reach a specification at younger ages will be more productive for meat production. Purebred Merino genetics will always be less productive in terms of carcass weight and muscle related productive traits (loin weight, semitendinosus muscle weight, eye muscle area) than BL and PD genetics, but the relative productivity of PD and BL genetics will depend on the traits used in the specification [see also Ponnampalam EN, Hopkins DL, Butler KL, Dunshea FR, Warner RD (2007) Genotype and age effects on sheep meat production. 2. Carcass quality traits. Australian Journal of Experimental Agriculure 47, 1147–1154]. The results suggest that selection for muscling had a greater impact on reducing ash mineral content associated with bone mineral mass than on increasing lean mass in the carcass.
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Aboneev, Vasily, Dmitry Aboneev, Ekaterina Aboneeva, Safarbi Kazanchev e Dastanbek Baimukanov. "Results of using different breed studs in commercial fine wool sheep breeding". E3S Web of Conferences 262 (2021): 02016. http://dx.doi.org/10.1051/e3sconf/202126202016.
Testo completoAbstract (sommario):
This work presents the material of research and production experiments on the crossing of stud rams of the North Caucasian meat and wool breed and Australian meat merino with fine wool ewes of a commercial herd. It is identified that the use of North Caucasian rams on fine wool ewes serves to increase the fertilizing ability and milk production of the breeding stock, to increase viability and resistance of young animals, as confirmed by the best morphometrical differences of crossbred offspring placentas. Crossbred offspring from semi-fine wool rams had a large live weight at birth at 21 days and at 4 months of age. The use of Australian producers did not have a significant effect on the above indicators of economically useful traits in comparison with purebred breeding.
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Li, G. D., K. R. Helyar, M. K. Conyers, L. J. C. Castleman, R. P. Fisher, G. J. Poile, C. J. Lisle, B. R. Cullis e P. D. Cregan. "Pasture and sheep responses to lime application in a grazing experiment in a high-rainfall area, south-eastern Australia. II. Liveweight gain and wool production". Australian Journal of Agricultural Research 57, n. 10 (2006): 1057. http://dx.doi.org/10.1071/ar05299.
Testo completoAbstract (sommario):
‘Managing Acid Soils Through Efficient Rotations (MASTER)’ is a long-term pasture–crop rotation experiment commenced in 1992. One of the objectives was to demonstrate the extent of crop, pasture, and animal responses to lime application on a typical acidic soil in the 500–800 mm rainfall zone of south-eastern Australia. Two types of pastures (perennial v. annual pastures) with or without lime application were established in 1992. Fifteen- to eighteen-month-old Merino hoggets were used as test animals and were changed annually. This paper reports the results of sheep responses to liming from the 4 continuous pasture treatments over 6 years from 1992 to 1997. The stocking rate was the same on all plots within a treatment during each rotation period, but was varied between treatments based on the pasture availability and sheep body condition. The most important findings from this study are that the limed treatments carried 29% and 27% more stock (up to 4 DSE/ha) than the unlimed treatments for perennial and annual pastures, respectively. As a result, the limed perennial pastures produced 27% more liveweight gain (62 kg/ha.year) and 28% more greasy wool (13 kg/ha.year) than unlimed perennial pastures, whereas the limed annual pastures produced 34% more liveweight gain (77 kg/ha.year) and 24% more greasy wool (11 kg/ha.year) than unlimed annual pastures. The significant responses to lime in liveweight and wool production were detected from the second growing season after the pastures were established. The increased sheep productivity on the limed treatment was due to a combination of increased pasture production and improved pasture quality. Perennial pastures showed a slight advantage in wool production, but not in liveweight gain. However, the seasonal variation of liveweight was greater on annual pastures than on perennial pastures. The larger variation in liveweight change could lead to more adverse effects on wool quality especially at high grazing pressures. Grazing management can be used to manipulate pasture and animal productivity to increase profits from lime use.
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Ferguson, M. B., J. M. Young, G. A. Kearney, G. E. Gardner, I. R. D. Robertson e A. N. Thompson. "The value of genetic fatness in Merino ewes differs with production system and environment". Animal Production Science 50, n. 12 (2010): 1011. http://dx.doi.org/10.1071/an10130.
Testo completoAbstract (sommario):
Selection against fatness in the Australian sheep industry has been a priority, but defining the true value of fat requires an understanding of the effects it has on both the value of lamb carcasses and on sheep productivity. A Merino flock with 10 years of reproduction data was used to analyse the correlation between breeding values for fatness at yearling age (YFAT) and the number of lambs born per ewe mated (NLB). In 2 production years, NLB was related (P < 0.01) to YFAT resulting in an extra 14 or 24.5 lambs born per 100 ewes mated per mm of YFAT. Based on these relationships, bio-economic modelling was used to assess the whole-farm value of YFAT for different sheep production systems and for years representing a low, medium and high response of NLB to YFAT. The changes in whole-farm profitability for a 1-mm increase in YFAT varied from $1000 (2%) for a wool enterprise with a low response up to $44 000 (25%) for a lamb enterprise with a high response. Appropriate carcass value discounts for higher YFAT were investigated but were not evident because of the small change in GR fat depth associated with the range of YFAT investigated. In most years there is no impact of YFAT on NLB and therefore profitability, yet in years where Merino ewes with higher YFAT produce higher NLB, ewes with an extra 1 mm of YFAT will be up to 25% more profitable. Therefore, care is required in determining the appropriate selection pressure to be placed on YFAT in Merino selection.
Tesi sul tema "Australian merino sheep Productivity Experiments"
1
Bray, Megan. "Regulation of wool and body growth : nutritional and molecular approaches". Title page, contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09PH/09phb8267.pdf.
Testo completoAbstract (sommario):
"May 2002" Includes bibliographical references (leaves 148-164) Describes a series of novel experiments designed to enhance our understanding of nutrient utilisation for growth of wool and the whole body.
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Bray, Megan. "Regulation of wool and body growth : nutritional and molecular approaches / Megan Bray". Thesis, 2002. http://hdl.handle.net/2440/21832.
Testo completoAbstract (sommario):
"May 2002"Includes bibliographical references (leaves 148-164)
xi, 164 leaves : ill. ; 30 cm.
Describes a series of novel experiments designed to enhance our understanding of nutrient utilisation for growth of wool and the whole body.
Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 2002
3
Hill, Jane Adair. "Phenotypic and genetic parameters for the S.A. Strongwool merino strain with an emphasis on skin characters as early indicators of wool productivity". 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phh6463.pdf.
Testo completoAbstract (sommario):
Bibliography: leaves 325-341. Skin and fleece measurements were recorded at different ages for both male and female sheep from the Turretfield Merino Resource Flock and used to estimate the heritability of each trait and the phenotypic and genetic correlations among and between the skin and fleece traits. Generally, the heritability of each trait was high, which indicates that both the fleece and skin traits should respond well to selection.
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Hill, Jane Adair. "Phenotypic and genetic parameters for the S.A. strongwool merino strain with an emphasis on skin characters as early indicators of wool productivity / by Jane Adair Hill". Thesis, 2001. http://hdl.handle.net/2440/21721.
Testo completoAbstract (sommario):
Includes bibliographical references (leaves 325-341).xxvii, 341 leaves : ill. ; 30 cm.
Skin and fleece measurements were recorded at different ages for both male and female sheep from the Turretfield Merino Resource Flock and used to estimate the heritability of each trait and the phenotypic and genetic correlations among and between the skin and fleece traits. Generally, the heritability of each trait was high, which indicates that both the fleece and skin traits should respond well to selection.
Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 2001