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1
Doran-Browne, Natalie A., John Ive, Phillip Graham e Richard J. Eckard. "Carbon-neutral wool farming in south-eastern Australia". Animal Production Science 56, n. 3 (2016): 417. http://dx.doi.org/10.1071/an15541.
Testo completoAbstract (sommario):
Ruminant livestock production generates higher levels of greenhouse gas emissions (GHGE) compared with other types of farming. Therefore, it is desirable to reduce or offset those emissions where possible. Although mitigation options exist that reduce ruminant GHGE through the use of feed management, flock structure or breeding management, these options only reduce the existing emissions by up to 30% whereas planting trees and subsequent carbon sequestration in trees and soil has the potential for livestock emissions to be offset in their entirety. Trees can introduce additional co-benefits that may increase production such as reduced salinity and therefore increased pasture production, shelter for animals or reduced erosion. Trees will also use more water and compete with pastures for water and light. Therefore, careful planning is required to locate trees where the co-benefits can be maximised instead of any negative trade-offs. This study analysed the carbon balance of a wool case study farm, Talaheni, in south-eastern Australia to determine if the farm was carbon neutral. The Australian National Greenhouse Gas Inventory was used to calculate GHGE and carbon stocks, with national emissions factors used where available, and otherwise figures from the IPCC methodology being used. Sources of GHGE were from livestock, energy and fuel, and carbon stocks were present in the trees and soil. The results showed that from when the farm was purchased in 1980–2012 the farm had sequestered 11 times more carbon dioxide equivalents (CO2e) in trees and soil than was produced by livestock and energy. Between 1980 and 2012 a total of 31 100 t CO2e were sequestered with 19 300 and 11 800 t CO2e in trees and soil, respectively, whereas farm emissions totalled 2800 t CO2e. There was a sufficient increase in soil carbon stocks alone to offset all GHGE at the study site. This study demonstrated that there are substantial gains to be made in soil carbon stocks where initial soils are eroded and degraded and there is the opportunity to increase soil carbon either through planting trees or introducing perennial pastures to store more carbon under pastures. Further research would be beneficial on the carbon-neutral potential of farms in more fertile, high-rainfall areas. These areas typically have higher stocking rates than the present study and would require higher levels of carbon stocks for the farm to be carbon neutral.
2
Littleton, Judith. "Dental wear and age grading at Roonka, South Australia". American Journal of Physical Anthropology 163, n. 3 (4 aprile 2017): 519–30. http://dx.doi.org/10.1002/ajpa.23226.
Testo completo
3
Doyle, PT, RA Love e TW Plaisted. "Mineral supplementation and wool production of young Merino sheep on the south coast of Western Australia". Australian Journal of Experimental Agriculture 35, n. 4 (1995): 437. http://dx.doi.org/10.1071/ea9950437.
Testo completoAbstract (sommario):
Wool-free liveweight change (LWC), wool growth rate, annual wool production, and wool characteristics of young Merino wethers fed supplements of lupins with gypsum or a multi-element mineral lick were examined in 12 experiments at 5 farms between 1989 and 1992. The source of sheep varied between experiments; age was 4.5-6.5 months and liveweight 28-37 kg at the beginning of supplementation. Sheep were fed lupins, lupins coated with gypsum (15-20 g/kg lupins), or lupins along with access to the mineral lick (offered at 140 g/sheep.week). The amount of lupins offered in all treatments within any experiment was the same. Supplementary feeding varied between experiments from 150 to 240 days. The sheep grazed annual pastures at stocking rates of 8-1 6.7ha. Average lick intake was 12-18 g/sheep. day. During supplementary feeding, there was considerable variation in LWC (-80 to +110 g/day) and clean wool growth rates (3.8-15.1 g/day) within and between experiments. However, there was no significant positive effect of gypsum or mineral lick supplementation on LWC or clean wool growth rates during or after supplementary feeding in any experiment. There were positive (P<0.01) relationships between LWC and clean wool growth rates during supplementation. Also, for some spring-shorn sheep types, staple strength of wool was linearly related (P<0.01) to LWC in the period before the position of break in the wool staple. Annual wool production, average fibre diameter, and staple strength of midside wool were not significantly increased by supplements of gypsum or mineral lick in any experiment.
4
Vere, D. T., P. M. Dowling, R. E. Jones e D. R. Kemp. "Economic impact of Vulpia in temperate pasture systems in south-eastern Australia". Australian Journal of Experimental Agriculture 42, n. 4 (2002): 465. http://dx.doi.org/10.1071/ea01100.
Testo completoAbstract (sommario):
An increasing incidence of annual grasses is considered to be a primary cause of decline in the productivity of Australia's temperate pasture systems. In particular, Vulpia (silver grass) comprises a significant proportion of the biomass of many temperate pastures and can seriously affect livestock productivity. The main economic effects of Vulpia include reducing pasture carrying capacities, contaminating produce and competing with more desirable pasture species. This paper presents the results of an economic evaluation of the costs of Vulpia and the long-term benefits of improving Vulpia management in the high-rainfall areas of south-eastern Australia. The evaluation used an integrated economic modelling system that determined the grazing system and livestock industry impacts of Vulpia and translated these into measures of economic welfare change that enabled the benefit-cost analysis of various levels of Vulpia management to be undertaken. With a focus on wool, the analysis established the high annual costs of Vulpia to wool producers and consumers, together with substantial long-term economic benefits that could potentially result from reducing the incidence of Vulpia in pastures. Total annual costs to the wool industry in the temperate pasture zone of New South Wales and Victoria ranged between A$7 and $30 million, while the potential discounted net benefits to the Australian and international wool industries were between $32 and $287�million over a 15-year period at a real discount rate of 5%. These estimates provide a strong economic basis for promoting improved management strategies for reducing Vulpia incidence in pastures.
5
Campbell, A. J. D., J. W. A. Larsen e A. L. Vizard. "The effect of annual shearing time on wool production by a spring-lambing Merino flock in south-eastern Australia". Animal Production Science 51, n. 10 (2011): 939. http://dx.doi.org/10.1071/an10270.
Testo completoAbstract (sommario):
Time of shearing affects many aspects of wool production and sheep health but no study has examined these factors concurrently in a spring-lambing, self-replacing Merino flock in southern Australia. A 5-year field experiment compared wool production in spring-lambing Merino ewes and their progeny shorn at different times and managed under commercial conditions in south-eastern Australia. Groups of 200 adult ewes were shorn in December, March or May, and their progeny were shorn in December or October, March or June, or May or July, respectively. There was no consistent association between time of shearing and the staple strength of wool (P = 0.73). December-shorn ewes produced significantly lighter and finer fleeces (average 19.1 μm, 3.0 kg clean weight) than did March-shorn ewes (19.4 μm, 3.1 kg). Fleeces from ewes shorn in May were of similar weight to those from March-shorn ewes (3.1 kg), but they were of significantly broader diameter (19.7 μm). In young sheep, desirable changes in some wool characteristics for each shearing group were offset by undesirable changes in others. On the basis of median historical (1991–2006) wool prices, shearing ewes in March and their progeny first in June produced the greatest total value of wool over a sheep’s lifetime ($161/head). The wool values per head for other shearing times were as follows: March (weaners)–March (ewes): $158; October–December: $157; December–December: $153; July–May: $151; and May–May: $148. Thus, December and March shearing were appropriate alternatives for maximising wool value produced from a self-replacing Merino flock in south-eastern Australia, whereas May was a less preferable shearing time because it always produced wool of lesser value.
6
Albertsen, TO, RH Casey e KP Croker. "Accumulation and dissipation of dieldrin in mature wethers in the south-west of Western Australia". Australian Journal of Experimental Agriculture 35, n. 3 (1995): 331. http://dx.doi.org/10.1071/ea9950331.
Testo completoAbstract (sommario):
The concentrations of dieldrin in body and wool fats of wethers grazed on 6 dieldrin-contaminated sites in the south-west of Western Australia were monitored over 2.5 years. Soil and pasture concentrations of dieldrin, a legacy of previous horticultural activities at these sites, were also measured. The concentrations of dieldrin in the soils varied from about 0.2 to 1.7 m a g . The production of the pastures at all sites showed a typical Mediterranean pattern with peak production in spring. The quantity of dry matter available ranged from <1000 kg/ha during summer-autumn to 10000 kg/ha in spring. In some samples the concentration of dieldrin in the dried plant material was above the accepted limit of 0.01 m a g for fresh material, but there were decreases over spring because of the substantial increase in the amount of dry matter available. The concentrations of dieldrin in the body and wool fats of the wethers increased during the winter and peaked at the start of spring, with the highest mean concentrations (mg/kg) in 1989 of 0.09-1.10 in body fats and 0.07-0.63 in wool fats. During spring the concentrations decreased and were at relatively low levels at the start of summer, with mean concentrations (mg/kg) of 0.02-0.72 in body fats and 0.01-0.18 in wool fats. Detailed results from 2 sites are discussed: Carbunup, with poorly structured loam soil; and Donnybrook, with good loam soil. On paddocks contaminated with dieldrin, production of wool with low concentrations of dieldrin is possible. If sheep grazed on contaminated paddocks are to be slaughtered, they should be sold in late spring, when concentrations of organochlorines in body fat should be low, or they should be run on uncontaminated land for about 2 months before their sale for slaughter.
7
Bird, PR, PR Bird, JD Kellas, JD Kellas, GA Kearney, GA Kearney, KN Cumming e KN Cumming. "Animal production under a series of Pinus radiata-pasture agroforestry systems in South-West Victoria, Australia". Australian Journal of Agricultural Research 46, n. 6 (1995): 1299. http://dx.doi.org/10.1071/ar9951299.
Testo completoAbstract (sommario):
Liveweight and greasy wool production data from young wethers were collected for the period autumn to early summer for the years 1986 to 1994 from an on-going Pinus radiata-pasture project at Carngham, Victoria. A plantation established in 1981 on a grazing property was thinned in 1983 to give trees spaced at: (i) no trees (a grazing control), (ii) 8 mx 12 m, (iii) 4 mx9 m, (iv) 4 mx3 m in a 5-row belt then a 10-row pasture gap, and (v) 2 mx3 m (original spacing). By 1989 the density of trees in these systems was slightly reduced by windthrow, animal damage and thinning to (ii) 60 trees/ha, (iii) 200 trees/ha wide-spaced, (iv) 200 trees/ha 5-row belt and (v) 1360 trees/ha. All trees in systems (ii), (iii) and (iv) had been pruned to 6 m by late 1992. The sheep stocking policy was initially based on a set 10 sheep ha-1. Since 1991 the stocking rate has been varied yearly in an attempt to maintain similar production per sheep. The pastures were re-sown in 1989 with perennial rye-grass and subterranean clover cultivars. Since 1991, wool production per ha from the 200 trees/ha wide-spaced system has been consistently less than in systems (i), (ii) and (iv). Wool production among systems differed significantly since 1992. Expressed as a percentage of wool production achieved on open pasture, the relative values for the agroforestry systems from 1990 to 1994 as follows.
8
Henry, B. K., D. Butler e S. G. Wiedemann. "Quantifying carbon sequestration on sheep grazing land in Australia for life cycle assessment studies". Rangeland Journal 37, n. 4 (2015): 379. http://dx.doi.org/10.1071/rj14109.
Testo completoAbstract (sommario):
The sheep industry has played an important role in Australia’s development and economy over the 220 years since European settlement and remains an important land use in Australia, occupying an estimated 85 million ha of continental land mass. Historically, deforestation was carried out in many sheep-rearing regions to promote pasture growth but this has not occurred within recent decades and many wool producers have invested in planting trees as well as preserving patches of remnant vegetation. Although the limitations of single environmental impact studies are recognised, this paper focuses on the contribution of carbon sequestration in trees and shrubs on sheep farms to the global warming potential impact category in life cycle assessment of wool. The analysis represents three major wool-producing zones of Australia. Based on default regional yields as applied in Australia’s National Inventory model, FullCAM, CO2 removals in planted exotic pines and mixed native species were estimated to be 5.0 and 3.0 t CO2 ha–1 year–1, respectively, for the Northern Tablelands of New South Wales in the ‘high-rainfall zone’ and 1.4 t CO2 ha–1 year–1 for mixed native species in the ‘sheep-wheat zone’ of Western Australia. Applying modified factors allowing for the higher measured growth rates in regions with rainfall >300 mm, gave values for native species reforestation of 4.4 and 2.0 t CO2 ha–1 year–1 for New South Wales and Western Australia, respectively. Sequestration was estimated to be 0.07 t CO2 ha–1 year–1 over 100 years for chenopod shrublands of the ‘pastoral zone’ of South Australia but this low rate is significant because of the extent of regeneration. Sequestration of soil organic carbon in improved permanent pastures in the New South Wales Northern Tablelands was evaluated to be highly uncertain but potentially significant over large areas of management. Improved data and consistent methodologies are needed for quantification of these benefits in life cycle assessment studies for wool and sheep meat, and additional impact categories, such as biodiversity, need to be included if the public and private benefits provided by good management of vegetation resources on farms are to be more fully recognised.
9
McGilchrist, P., J. L. Perovic, G. E. Gardner, D. W. Pethick e C. G. Jose. "The incidence of dark cutting in southern Australian beef production systems fluctuates between months". Animal Production Science 54, n. 10 (2014): 1765. http://dx.doi.org/10.1071/an14356.
Testo completoAbstract (sommario):
Dark cutting is detrimental to meat quality and therefore is the major cause of carcass downgrades under the Meat Standards Australia grading system. This study quantified the variation between months in the incidence of dark cutting, in southern Australia. Four years of Meat Standards Australia grading data, from nine individual beef processors in Western Australia, South Australia, Victoria and Tasmania, was utilised for the analysis. The dataset contained 42 162 slaughter groups, of 10 or more grass-fed cattle, which allowed for the percentage of dark cutters per slaughter group to be analysed. The interaction between month, year and state was significant (P < 0.001). The lowest risk of dark cutting for South Australia and Western Australia was in October (1.53% ± 0.75 and 6.96% ± 0.76) and November in Tasmania and Victoria (7.34% ± 0.9 and 5.27% ± 0.81) potentially when feed availability and quality is highest. The incidence of dark cutting was highest for all states during the period from February to June. Lower pasture availability and quality in combination with higher levels of stress due to extreme high or low temperatures during this time could all contribute to the higher incidences. The findings of this study show that procurement and management decisions made by cattle buyers, producers and processors need to change throughout the year to help mitigate the incidence of dark cutting carcasses and reduce financial loss.
10
Craig, AD. "The performance of Merino ewes and lambs grazing two cultivars of Trifolium subterraneum at Kybybolite, South Australia". Australian Journal of Experimental Agriculture 32, n. 5 (1992): 605. http://dx.doi.org/10.1071/ea9920605.
Testo completoAbstract (sommario):
Two cultivars of subterranean clover, Trikkala and Mt Barker, were continuously grazed by Merino ewes and lambs at 3 stocking rates (8, 13, 18 ewes/ha) from 1976 to 1981. The sheep were assessed for liveweight, fleeceweight, fibre diameter, staple length, wool yield and lambing performance including lambing, marking and weaning percentage. From September 1978 onward, ewes grazing Trikkala pastures were consistently heavier than those grazing Mt Barker pastures, and they produced heavier fleeces in 1978 and 1980, with a 3 and 9% greater total wool production. The heavier fleeces of 1980 were associated with a larger fibre diameter. There were no cultivar differences in lambing performance. Cultivar treatment had no effect on lamb birthweight, but in 1980 the Trikkala lambs were, on average, 3.5 kg heavier at weaning. These lambs also produced heavier fleeces than lambs on the Mt Barker pastures. Higher stocking rates produced decreases in all of the animal performance variables measured. The results of this study suggest that improved livestock performance may only occur if animals are grazed on higher performing cultivars for at least 3 years.
11
Fleming, P. J. S., J. D. Croft e H. I. Nicol. "The impact of rabbits on a grazing system in eastern New South Wales. 2. Sheep production". Australian Journal of Experimental Agriculture 42, n. 7 (2002): 917. http://dx.doi.org/10.1071/ea01107.
Testo completoAbstract (sommario):
Much research, time and money have been invested in the control of rabbits in Australia, yet the relationship between rabbit density and livestock production losses has not been quantified. We experimentally investigated the variations in sheep production parameters caused by 4 densities of rabbits, 0, 24, 48 and 72 rabbits/ha. Medium to strong wool merino wethers were run at a constant stocking rate in replicated plots with rabbits at 4� different densities. Sheep liveweight and body condition and wool production variables were measured over 3�years. Low to medium densities of rabbits were not found to reduce liveweights of wethers, whereas wethers run with the high density of rabbits were significantly lighter. The presence of rabbits reduced the body condition of sympatric sheep with the lowest body condition recorded at the high rabbit density. Mean greasy fleece weights, wool yields and clean-fleece weights were significantly different between densities of rabbits. Wethers run with the high rabbit density grew less wool than the wethers run with the other 3 densities of rabbits. The cumulative gross return per ha from wool production was highest for the medium rabbit density and lowest at high rabbit density. At the conclusion of this short-term experiment, the presence of some rabbits enhanced returns from wool production because of lower fibre diameter and comparable clean-fleece weights of fleeces grown at low and medium rabbit densities. These production characteristics might have been caused by synergistic effects on pasture growth or a sheep stocking rate that was too conservative for the prevailing seasonal conditions. At high rabbit density, competition for pasture between rabbits and sheep overrode possible synergistic and understocking effects. The economic implications of the presence of rabbits on merino sheep production are discussed.
12
Doyle, PT, TW Plaisted e RA Love. "Supplementary feeding pattern and rate of liveweight gain in winter-spring affect wool production of young Merino sheep on the south coast of Western Australia". Australian Journal of Experimental Agriculture 35, n. 8 (1995): 1093. http://dx.doi.org/10.1071/ea9951093.
Testo completoAbstract (sommario):
The effects of different supplementary feeding practices in summer-autumn and management strategies on green pasture on liveweight change, wool growth rate, annual wool production and wool characteristics of young Merino wethers were examined at 2 farms. The grain feeding treatments were lupins (L) or lupins and oats (LO) fed in amounts that were adjusted to try and maintain liveweight, or lupins and oats (LOG) fed at a higher rate. The objectives of liveweight maintenance or gain were not always achieved, but liveweight patterns differed between LOG compared with L or LO during summer-autumn. The sheep used at farm 1 were aged 4.5 months and liveweight 32 kg at the start of the experiment, while those at farm 2 were 6.5 months and liveweight 39 kg. The stocking rate in summer-autumn was 8 wethers/ha at both farms. During supplementation, sheep on LOG had a higher (P<0.05) liveweight change compared with those on L or LO (farm 1, 15 v. -8 g/sheep. day; farm 2, -35 v. -51 g/sheep. day) and clean wool growth rates (farm 1, 7.1 v. 6.4 g/sheep. day; farm 2, 5.1 v. 4.8 g/sheep.day). The sheep on LOG grew broader (P<0.05) wool than those on L or LO (farm 1, 19.0 v. 18.5 �m; farm 2, 21.7 v. 20.8 �m), and at farm 1 length was also greater (P<0.05) (114 v. 111 mm), while at farm 2 staple strength was greater (P<0.01) (22.9 v. 16.4 N/ktex). There were no significant differences in annual clean wool production. There were positive (P<0.01) relationships between staple strength and liveweight change to the time of minimum liveweight in summer-autumn. After green pasture on offer reached 500 kg DM/ha in autumn, different liveweight change patterns were achieved in 2 groups (LS, lower stocking rates; HS, higher stocking rates) of sheep at each farm by adjusting stocking rates. Within a farm, the LS and HS groups were comprised of equal numbers of sheep from each replicate of the supplementary feeding treatments. There were differences (P<0.05 to 0.01) in liveweight change between LS and HS (farm 1, 93 v. 72 g/day; farm 2, 127 v. 60 g/day), the differences being more pronounced at farm 2. The differential stocking rates at farm 2 resulted in differences in clean wool growth rates (P<0.01), in clean wool production (4.22 v. 4.53 kg, P<0.05), and fibre diameter (20.8 v. 21.4 �m, P<0.01), but there were no significant effects on staple length or strength. There were no significant effects of the supplementary feeding treatments imposed in summer-autumn on the responses to the stocking rate treatments on green pasture.
13
Merrett, David Tolmie, e Simon Ville. "Accounting for Nonconvergence in Global Wool Marketing before 1939". Business History Review 89, n. 2 (2015): 229–53. http://dx.doi.org/10.1017/s0007680515000641.
Testo completoAbstract (sommario):
From the mid-nineteenth century, raw wool became a global commodity as new producing countries in the Southern Hemisphere supplied the world's growing textile industries in the North. The selling practices of these big-five exporters—Australia, New Zealand, South Africa, Argentina, and Uruguay—ranged from auction through a hybrid of auction and private sale to exclusively private sale. We explore why these countries persisted with different marketing arrangements, contradicting two streams of literature on institutions: isomorphism and the new institutional economics. The article makes several important contributions through blending distinct branches of theory and by focusing on the international constraints to convergence in an earlier period of globalization.
14
Gardener, M. R., R. D. B. Whalley e B. M. Sindel. "Ecology of Nassella neesiana, Chilean needle grass, in pastures on the Northern Tablelands of New South Wales. I. Seed production and dispersal". Australian Journal of Agricultural Research 54, n. 6 (2003): 613. http://dx.doi.org/10.1071/ar01075.
Testo completoAbstract (sommario):
Nassella neesiana (Trin. & Rupr.) Barkworth (Chilean needle grass) originated in South America and is now a widespread weed in pastures in south-eastern Australia. To date, little research on the biology of N.�neesiana has been undertaken in Australia. This study investigated several aspects of the biology of N. neesiana in pastures on the Northern Tablelands of New South Wales. The main flowering period for N. neesiana in Australia was shown to extend from November to February and is similar to that in South America. Potential for production of panicle seeds was large and varied from 1584 seeds/m2 in 1995 to 22 203 seeds/m2 in 1996 as a result of changes in the density of flowering tillers per unit area. Nassella neesiana produced a further 7.2 cleistogenes (hidden seeds in the flower stem) on average per tiller. Hence, total potential seed production (panicle seeds and cleistogenes) was 28 282 and 8036 seeds/m2 in 1996 and 1997, with the cleistogenes accounting for 21.5 and 26.1% of the total respectively. Furthermore, the production of cleistogenes was not affected by clipping flowering tillers at 3 different heights. Three possible dispersal mechanisms of N. neesiana seeds were investigated. Adherence of seeds to the wool appeared to be the most effective. Twenty-five per cent of seeds that were picked up naturally in the wool of sheep after grazing in a paddock of N. neesiana, remained after 5 months. Shearing just before seed set reduced the number of seeds adhering to the wool. An average of 1.7% of panicle seeds and 5.3% of cleistogenes fed to Angus steers passed through the animal intact within 4 days, but <50% of these seeds were viable. The majority of seeds recovered from a wind dispersal experiment were within 1 m of the parent plant and the furthermost seed was 2.8 m away. The implications of these results for management are discussed.
15
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.
16
Kleemann, DO, RW Ponzoni, JE Stafford e RJ Grimson. "Carcass composition of the South Australian Merino and its crosses with the Booroola and Trangie Fertility Merino". Australian Journal of Experimental Agriculture 28, n. 2 (1988): 167. http://dx.doi.org/10.1071/ea9880167.
Testo completoAbstract (sommario):
South Australian medium-wool (M), non- Peppin medium-wool Booroola (B) and Peppin medium-wool Trangie Fertility (TF) Merino rams were joined to M ewes at Turretfield Research Centre, South Australia, in 2 years. Carcass composition was assessed in the ewe and wether progeny at 2 mean slaughter liveweights, viz. 24 and 38 kg. When adjusted to the same carcass weight, B x M had 13% more carcass chemical fat, 15% more subcutaneous fat, 6% less bone and the same lean tissue as M. The same result was observed for TF x M in relation to M in year 2. However, TF x M had more lean and the same amount of subcutaneous and chemical fat as M in year 1. Within the Booroola strain, there were no differences between offspring from 3 sires with genotype FF and the 1 sire with + + for any of 5 variables analysed. We conclude that crossing the Booroola with the South Australian Merino produces carcasses with the same amount of lean tissue, less bone and more fat when compared at the same carcass weight. The rank of TF x M with the other strains for the major carcass components remains obscure owing to a strain x year interaction.
17
Charlick, AJ, e GW Arnold. "Effect of bearing and rearing lambs on Merino wool production". Australian Journal of Experimental Agriculture 30, n. 5 (1990): 591. http://dx.doi.org/10.1071/ea9900591.
Testo completoAbstract (sommario):
Over a 15-year period, the greasy fleece weights of medium-wooled Merino ewes lambing in June in a 625 mm winter rainfall area in south-western Australia were examined in relation to the numbers of lambs born and reared. The ewes were set stocked at 6.7 ewes/ha on annual pasture. During this period selection for increased wool production was undertaken. A generalised linear model was used to assess the effects of bearing and rearing lambs. There was a significant (P<0.05) year x lambing interaction because of a different response over years 1-7 from that over years 8-15. Over years 1-7 when dry ewes cut an average of 4250 g greasy wool, ewes raising single lambs cut 185 g less wool (P<0.001); the few that raised twins cut a similar amount of wool to dry ewes. In years 8-15, wool production of dry ewes increased to an average of 5524 g. Ewes that lambed but lost their lambs cut 386 g less wool, those raising single lambs 652 g less wool, and those raising twins 846 g less wool. Over years 8-15, a second flock in which some ewes lambed twice a year was examined. These ewes received supplementary feed for out of season lambing. Those that raised 2 single lambs in a year cut 1120 g less wool than dry ewes.
18
Behrendt, R., A. J. van Burgel, A. Bailey, P. Barber, M. Curnow, D. J. Gordon, J. E. Hocking Edwards, C. M. Oldham e A. N. Thompson. "On-farm paddock-scale comparisons across southern Australia confirm that increasing the nutrition of Merino ewes improves their production and the lifetime performance of their progeny". Animal Production Science 51, n. 9 (2011): 805. http://dx.doi.org/10.1071/an10183.
Testo completoAbstract (sommario):
Experiments conducted by Lifetimewool at plot-scale have shown that differences in the maternal liveweight during pregnancy and lactation (liveweight profiles) of individual Merino ewes influences their wool production and reproductive rate as well as the birthweight, survival, weaning weight and lifetime wool production of their lambs in a predictable manner. This study determined whether these impacts of nutrition of the ewe on ewe and progeny performance are measurable on commercial properties across southern Australia at a paddock-scale where ewes were aggregated into flocks with a greater spread of the date of conception and where the liveweight profile of the flocks were managed based on random samples of 100 ewes and liveweight was uncorrected for fleece weight or conceptus. Eighteen paddock-scale experiments at 15 sites were conducted in cooperation with wool producers across Victoria, Western Australia, New South Wales, South Australia, and Tasmania. Each co-operator joined up to 1000 mixed aged adult Merino ewes. The flock was scanned using ultrasound at Day 50 from the start of joining to identify those ewes that conceived during the first 21 days of joining. These ewes were then split at random into two treatments and fed to achieve a target difference in liveweight of 10 kg or ~1 condition score/fat score at lambing. The production of ewes during their year of pregnancy and following their next joining was measured as was the performance of their progeny up to their third shearing. Only the 13 paddock-scale experiments that achieved a difference in liveweight profile at lambing of at least 4 kg were included in the final analysis. In these 13 experiments, increasing the nutrition of Merino ewes during pregnancy clearly increased the clean fleece weight and fibre diameter in ewes and the survival and lifetime wool production of their lambs. In most cases the size of the effect was not significantly different to that predicted by the relationship derived using individual liveweight profiles in the plot-scale experiments. This confirms that managing average ewe liveweight or condition score/fat score profile through better nutrition will lead to predictable increases in the performance of ewes and their progeny performance under commercial conditions and validates the use of the plot-scale relationships in economic analyses.
19
Bell, Stephen. "Aimé Bonpland and Merinomania in Southern South America". Americas 51, n. 3 (gennaio 1995): 301–23. http://dx.doi.org/10.2307/1008225.
Testo completoAbstract (sommario):
As an integrating theme in the biological or ecological expansion of Europe, merino sheep were so important that one authority on their dispersal sees the nineteenth century standing as “the century of the Merino.” Merinos produce a wool of distinctive quality, one long appreciated for providing warmth without excessive weight. Guarded for centuries by Spanish monopoly, the breed's status as something of a prize outside Spain began to change in 1808 with the Napoleonic invasion of the Iberian peninsula. By around 1820, a major new phase in merino dispersal was underway with its adaptation to some of the vast grassland ecosystems in the Europeanizing peripheries. The breed was of critical importance to the settlement and development of Australia. It was also highly important in other parts of the southern hemisphere, including in the transformation of existing cattle cultures on the great grassland regions of the Río de la Plata. Here the merino formed the leading edge of rural modernization, offering real potential for ground-up development.
20
Ayres, J. F., M. J. McPhee, A. D. Turner e M. L. Curll. "The grazing value of tall fescue (Festuca arundinacea) and phalaris (Phalaris aquatica) for sheep production in the northern tablelands of New South Wales". Australian Journal of Agricultural Research 51, n. 1 (2000): 57. http://dx.doi.org/10.1071/ar99080.
Testo completoAbstract (sommario):
The grazing value of phalaris–white clover and tall fescue–white clover pastures was compared in a temperate summer-rainfall environment in the high rainfall zone of eastern Australia. Data were derived from an experiment which evaluated pasture cultivars when grown in binary mixtures and grazed by sheep. The data were also simulated with the decision support system SheepO (Version 4.0) and validated by visual techniques, deviance measures, and statistical tests. The model generally simulated green biomass, liveweight gain, and clean fleece weight with acceptable accuracy. Pasture based on tall fescue–white clover produced more green pasture biomass in all seasons, in all years, and at both low (10 sheep/ha) and high (15 sheep/ha) stocking rates when compared with phalaris–white clover. Sheep grazing tall fescue–white clover pasture were turned off about 5 kg heavier each year and produced about 0.6 kg/head more clean fleece weight; the wool production per head of sheep grazing tall fescue–white clover at 15 sheep/ha was similar to that for sheep grazing phalaris–white clover pasture at 10 sheep/ha. These differences in wool production were accompanied by consistent effects on wool quality; the fleeces of sheep grazing tall fescue–white clover pasture were markedly sounder in tensile strength but broader in fibre diameter. These data and the SheepO simulations highlight the potential for pasture cultivars with enhanced seasonal growth and nutritive value to alleviate feed-gaps and improve the feed-base for grazing animals.
21
PICKARD, JOHN. "The Transition from Shepherding to Fencing in Colonial Australia". Rural History 18, n. 2 (ottobre 2007): 143–62. http://dx.doi.org/10.1017/s0956793307002129.
Testo completoAbstract (sommario):
AbstractThe transition from shepherding to fencing in colonial Australia was a technological revolution replacing labour with capital. Fencing could not be widespread in Australia until an historical conjunction of technological, social and economic changes: open camping of sheep (from about 1810), effective poisoning of dingoes with strychnine (from the mid-1840s), introduction of iron wire (1840s), better land tenure (from 1847), progressive reduction of Aboriginal populations, huge demand for meat (from 1851) and high wages (from 1851). Labour shortages in the gold-rushes of the early 1850s were the final trigger, but all the other changes were essential precursors. Available data are used to test the alleged benefits of fencing: a higher wool cut per head; an increased carrying capacity; savings in wages and the running costs of stations; less disease in flocks; larger sheep; higher lambing percentages, and use of land unsuitable for shepherding. Many of the benefits were real, but some cannot be verified. By the mid-1880s, over ninety-five per cent of sheep in New South Wales were in paddocks, wire fences were spreading rapidly, and the cost of fences was falling. However, shepherding persisted in remote northern areas of Australia until well into the twentieth century.
22
Young, J. M., G. Saul, R. Behrendt, F. Byrne, M. McCaskill, G. A. Kearney e A. N. Thompson. "The economic benefits of providing shelter to reduce the mortality of twin lambs in south-western Victoria". Animal Production Science 54, n. 6 (2014): 773. http://dx.doi.org/10.1071/an13256.
Testo completoAbstract (sommario):
Achieving higher lamb weaning percentages by reducing lamb mortality can improve the profitability of sheep enterprises. In this paper we estimated the financial benefits from providing shelter to reduce the mortality of twin lambs in self-replacing Merino or dual-purpose Merino flock enterprises in south-west Victoria. A whole-farm bio-economic model (MIDAS) was initially used to estimate the increase in profit from reducing mortality of twin lambs and a second analysis included the costs of using perennial grass hedges to provide the shelter during lambing. The economic value of providing shelter was tested at three rates of twinning (10, 30 and 50%), three rates of mortality without shelter (70, 50 and 30%) and two levels of reduction in lamb mortality by providing shelter (25 and 50% reduction). A sensitivity analysis to wool and lamb prices, costs of establishing the grass hedges and stocking rates in the shelter area were also tested. Overall, more than 2500 scenarios were tested. Across the range of twinning rates and levels of twin mortality tested, at standard wool and meat prices, providing shelter to the dual-purpose Merino ewe flock was always profitable ($0.05 to 11.35/ewe) and the profits from providing shelter to the self-replacing Merino ewe flock were generally lower ($0.15 to $6.35/ewe). The impacts of changing wool and lamb prices depended on enterprise type, whereas the costs of establishment of the hedges or stocking rate of ewes in the hedge area during lambing had little impact on profitability. The main factor that determined the economic return from shelter was the reduction in mortality provided by the shelter but the proportion of twin-bearing ewes in the flock and the base rate of lamb mortality without shelter was also important. Overall, based on the assumptions used, we conclude that the profitability of many sheep enterprises lambing during frequent high chill weather conditions in temperate areas of south-eastern Australia could be improved by providing low cost shelter for twin-bearing Merino ewes lambing from July to September.
23
Davies, HL, PP Mann e B. Goddard. "A comparison of the effects of feed supplements cobalt and selenium, and perennial and annual pastures on the production of medium Peppin Merino weaner sheep in south-western Australia". Australian Journal of Experimental Agriculture 29, n. 3 (1989): 361. http://dx.doi.org/10.1071/ea9890361.
Testo completoAbstract (sommario):
Two experiments on weaner production are reported. In experiment 1, the liveweight and wool production were measured in medium Peppin Merino sheep that grazed at 10.5 weanerstha 8 plots of a mixed Phalaris aquatica-subterranean clover pasture or 8 plots of annual pasture (Trifolium subterraneum cv. Woogenellup and volunteer annual grass species). This was repeated over 2 years using autumn-born sheep; 4 groups on each pasture type were offered no supplement, 2 groups a cereal supplement (340 goats), and 2 groups of supplement isoenergetic with the cereal group but having a high protein meal replace some of the cereal (250 g oats and 60 g protein). The feed supplement was offered over the summer (January-April). The sheep on 2 of the unsupplemented plots and 1 of the 2 plots receiving either a cereal or cereal + protein supplement were offered access to a composite mineral block formulated to meet the mineral requirements of sheep with the exception of cobalt and selenium. There were 16 sheep on each plot within each group of 16 weaners, 4 were given an intraruminal cobalt 'bullet', 4 were given 5 mg of selenium orally, 4 given cobalt plus selenium and 4 were untreated controls. Experiment 2 was in year 3 with spring-born weaners on the same plots. The mineral block treatment was discarded on the plots receiving supplement and the effect of supplementary feeding at the beginning of March was compared with feeding in early January; barley was also compared with oats and protein. The stocking rate was raised to 13.5 sheep/ha. There were no statistically significant differences in sheep liveweight due to pasture type in either of the years of experiment 1 or experiment 2. Supplementation with cereals or protein-fortified cereals resulted in a significantly ( P < 0.05) increased liveweight at the end of March (5.6 kg in year 1,2.4 kg in year 2 of experiment 1, and 2.5 kg in experiment 2), and wool production (0.49 kg clean wool in year 1 and 0.3 1 kg in year 2 in experiment 1, and 0.49 in experiment 2). There was a significant liveweight response on the perennial plots to selenium + cobalt in year 1 of experiment 1. All cobalt-treated sheep were heavier ( P < 0.001) in year 2. Neither selenium nor cobalt significantly affected liveweight in experiment 2. The proportion of Phalaris aquatica on the perennial pasture diminished from 18% to less than 9% by the end of year 2 in experiment 1. These results suggest that, if perennial pastures cannot be maintained, then their establishment in the south-west of Western Australia would not result in greater animal production than on annual pasture. Decisions on using supplements would be dependent upon feed and wool prices.
24
Thorn, CW, e MW Perry. "Effect of chemical removal of grasses from pasture leys on pasture and sheep production". Australian Journal of Experimental Agriculture 27, n. 3 (1987): 349. http://dx.doi.org/10.1071/ea9870349.
Testo completoAbstract (sommario):
Pasture production, pasture composition and quality, and liveweight, body condition and wool growth of Merino weaner wethers were monitored over 2 seasons and at 2 stocking rates (4 and 8 sheep/ha) on a mixed annual grass-legume pasture sprayed with propyzamide to control grasses. Propyzamide virtually eliminated annual grasses from the pasture (less than 5 kg/ha of grass dry matter in spring v. 403 kg/ha on untreated pasture in 1981) and this carried over into the second season (61 kg/ha v. 647 kg/ha in spring 1982). Propyzamide treated pastures had less total dry matter (P = 0.05) throughout 1981: however, except for a single sample date, there was no effect of propyzamide on total available pasture in the second season. Increased growth of clover and capeweed compensated for the absence of the grasses. The higher stocking rate reduced available clover, capeweed and total dry matter (P = 0.05) throughout both years. Sheep grazing grass-free pastures had lower liveweights during winter in both years, but made compensatory gains during late spring and summer consistent with the higher quality (1.6 v. 1.07% nitrogen when sampled in January) of propyzamide treated pastures. In 198 1, wool growth rates were reduced at the higher stocking rate and total clean wool production was reduced from 4.55 kg/sheep at 4/ha to 3.65 kg/sheep at 8/ha. Pasture treatment had no effect on wool production in either year. The implications of using selective herbicides to remove the annual grass component of legume-based annual pastures in south-western Australia are dis cussed in relation to pasture and sheep production.
25
Scott, B. J., A. M. Ridley e M. K. Conyers. "Management of soil acidity in long-term pastures of south-eastern Australia: a review". Australian Journal of Experimental Agriculture 40, n. 8 (2000): 1173. http://dx.doi.org/10.1071/ea00014.
Testo completoAbstract (sommario):
Acidification of non arable soils under long-term pasture presents a major agricultural problem in the high rainfall areas (≥600 mm/year) of central and southern New South Wales and north-eastern Victoria. Some of these soils were already strongly acid to depth before agriculture. Evidence suggests that persistence of pasture species tolerant of acidic soils is being affected adversely on a number of severely acidic soils. Acidification processes are well understood but the capacity for grazing enterprises to pay for amendment by lime application is a major constraint in long-term pasture areas. In addition, soil acidification is likely to have substantial off-site effects on water quantity and quality and as a result, on dryland salinity. However, there is a paucity of scientific evidence to link soil acidity and dryland salinity in this way. Production from a grazing enterprise can be maintained by selecting plants for tolerance of acidity, surface application of lime or a combination of both. Responses by subterranean clover, lucerne and perennial grass (mainly phalaris and cocksfoot)-based pastures to incorporated lime are reported, but there is limited evidence of responses to surface applied lime. The movement of the lime effect into the soil from surface application is suggested as a major factor in controlling lime responses by plants. There is a need for more confidence in the benefits of topdressed lime in non arable soils before producers are likely to adopt the practice. High subsurface acidity in many soils is a major limitation to the range of species that can be grown. In the longer term, the use of lime may remove constraints on the use of productive species such as lucerne. Other options for acidic soils where slope is less than 10% are for the grazing system to be modified or intensified, or for crop or horticultural production. Costs of lime could be justified through more profitable enterprises than traditional grazing operations. Low input systems based on native grasses are intrinsically appealing, however, this is only possible where a premium is paid for such produce (such as super fine wool). Forestry is an option where suitable land and infrastructure are present and should slow soil acidification and minimise off-site impacts. Land retirement may be a useful option for some parts of the landscape that contribute disproportionately to environmental problems. Private and government funded land retirement may have a role to play.
26
Trompf, J. P., e P. W. G. Sale. "The paired-paddock model as an agent for change on grazing properties across south-east Australia". Australian Journal of Experimental Agriculture 40, n. 4 (2000): 547. http://dx.doi.org/10.1071/ea00046.
Testo completoAbstract (sommario):
A detailed study was undertaken on the pasture management practices of 146 producers across south-east Australia who participated in the Grassland’s Productivity Program (GPP) for 3 years between 1993 and 1997. The GPP was an extension program to assist wool producers to develop skills and gain confidence in their ability to manage more productive pastures on their farms. The program consisted of 50 farmer groups (200 farmers participating) spread across the 4 states of South Australia, southern New South Wales, Victoria and Tasmania. Each farmer established paired-paddocks on their own property to compare productive pastures with existing pastures. Productive pastures involve increased rates of fertiliser on pastures containing productive species, with stocking rate adjusted to consume available pasture. After 3 years of involvement in the GPP, there was a whole-farm increase in P fertiliser use by 6.3 kg P/ha, stocking rates by 2.6 dse/ha and annual pasture resowing by 0.9% of the farm, when averaged across the 146 participants. The participants were applying the productive pasture technology to almost a third of their properties in 1997 and the intention was to increase this to over half of their properties by 2000. The participants also changed farm management practices as the program effectively developed management skills. There were increases in the ability to assess pasture quality and quantity, livestock by weighing or physical assessment, and the ability to calculate per hectare production and per hectare gross margins. A high proportion of GPP participants were soil testing (0.92) and spring lambing (0.72) at the completion of the program. The results indicated that the adoption of productive pastures was generally consistent across south-east Australia for pastoral producers who participated in this program, although south-west Victorian and south-east South Australian GPP participants did increase whole-farm P application by more than GPP participants from outside that region. The widespread change in farming practice was attributed to the additive and interactive effect of the paired-paddock comparison, the guidance provided by the facilitator, the group interaction and the skills training. Each of these components of the paired-paddock model combined to form an effective agent for change to increase pasture productivity on these grazing properties.
27
Sanford, P., X. Wang, K. D. Greathead, J. H. Gladman e J. Speijers. "Impact of Tasmanian blue gum belts and kikuyu-based pasture on sheep production and groundwater recharge in south-western Western Australia". Australian Journal of Experimental Agriculture 43, n. 8 (2003): 755. http://dx.doi.org/10.1071/ea02226.
Testo completoAbstract (sommario):
The effect of Tasmanian blue gum (Eucalyptus globulus) belts and kikuyu (Pennisetum clandestinum) grass on livestock production and groundwater recharge was studied in the high rainfall zone (>600 mm/year) of south-western Western Australia from 1998 to 2001. The objective was to identify optimum combinations of tree belts and pasture for sustainable livestock production and the prevention of secondary salinisation. Treatments were annual pasture, in competition with trees at different orientations (east, west and south), kikuyu pasture in competition with trees at one orientation (west), compared with pasture in the absence of tree competition. Plots had 0, 20 or 36% of their area within 10 m of the tree belt where tree–pasture competition would be expected. Plots (0.48 ha) were stocked with Merino wether hoggets at 12 DSE/ha on annual pastures and 14 DSE/ha on kikuyu pastures. Additional sheep were placed on plots in spring and the annual pasture was destocked in autumn.Within the growing season, herbage mass was similar across both control treatments as a result of varying stock numbers. However, in summer and autumn the kikuyu control contained between 350 and 4900 kg DM/ha more herbage than the corresponding annual pasture. While both pastures accumulated similar amounts of herbage in 1998 and 2000, kikuyu accumulated more in 1999 (11 900 v. 9800 kg DM/ha) as a result of summer rain. Competition from tree belts significantly reduced adjacent annual pasture herbage accumulation (16% average reduction), although there was no difference among the levels of competition. Trees did not significantly affect adjacent kikuyu pasture herbage accumulation. Both carrying capacity and clean wool production per hectare were significantly higher on kikuyu pasture in 1999 and 2000. Tree competition also significantly reduced the carrying capacity of neighbouring annual and kikuyu pasture by an average of 10%. Clean wool production per hectare was significantly lower on annual pasture in combination with trees (11% reduction on average), but there was less effect of competition on kikuyu pasture. The kikuyu pasture used 115, 57 and 132 mm more water than the annual pasture in 1999, 2000 and 2001, respectively. The soil water deficit beneath the trees exceeded that below both control pastures by between 297 and 442 mm.Although the addition of tree belts to annual pasture provided substantial reductions in groundwater recharge, producers would also have to accept losses in livestock production. While kikuyu alone provided significant increases in livestock production and substantial reductions in groundwater recharge, the best compromise was kikuyu in combination with tree belts.
28
Young, J. M., A. N. Thompson, M. Curnow e C. M. Oldham. "Whole-farm profit and the optimum maternal liveweight profile of Merino ewe flocks lambing in winter and spring are influenced by the effects of ewe nutrition on the progeny's survival and lifetime wool production". Animal Production Science 51, n. 9 (2011): 821. http://dx.doi.org/10.1071/an10078.
Testo completoAbstract (sommario):
Profitability of sheep production systems in southern Australia is optimised at a stocking rate that provides adequate nutrition for breeding ewes and enables efficient utilisation of grown pasture and supplements. In this paper we used bio-economic modelling to develop optimum liveweight1 profiles for spring-lambing Merino ewes in different environments. The modelling included the impacts of the ewe liveweight profile on the production of the ewe and the survival and lifetime wool production of her progeny. Fifteen ewe liveweight profiles were analysed for each region to determine the profitability of varying ewe liveweight at joining, varying rate of loss of liveweight after joining and the rate of gain in liveweight from the minimum to lambing. The analyses support the hypotheses that whole-farm profitability is sensitive to the liveweight profile of Merino ewe flocks and that there is a liveweight profile that maximises whole-farm profit. The variation between the most and least profitable ewe liveweight profile was $69 0002 per farm ($14.30/ewe) for south-west Victoria, $51 000 per farm ($8.70/ewe) for Great Southern Western Australia and $33 300 per farm ($9.70/ewe) for southern New South Wales. The changes in profit were due to differences in costs of feeding to achieve the ewe liveweight profile and its influence on the production of both the ewes and their progeny. Failure to include the impacts of liveweight profile on progeny survival and lifetime wool production incorrectly identifies the optimum ewe liveweight profile and provided inaccurate estimates of profitability. The optimum liveweight profiles for ewes lambing in spring were similar for all three regions and insensitive to changing commodity prices, pasture productivity and management. The optimum profile was to join ewes at ~90% of the standard reference weight of the genotype, lose a small amount of weight after joining and regain weight in late pregnancy to return to the joining weight by lambing. Regaining the liveweight lost in early pregnancy by lambing is the most important target to achieve. The cost per farm of missing this liveweight target by 1 kg was $13 000 ($2.60/ewe) for south-west Victoria, $8900 ($1.45/ewe) for Great Southern Western Australia and $5500 ($1.65/ewe) for southern New South Wales. By contrast, the cost per farm of missing the joining target by 1 kg was $5500 for south-west Victoria and less than $2000 across the other two regions. Whole-farm profit increased with increasing stocking rate up to an optimum and regardless of stocking rate there is an additional opportunity to increase whole-farm profit by up to 15% by managing ewes to achieve the optimum liveweight profile. This indicates that the optimum liveweight profile should be achieved by increasing the level of grain feeding and altering the timing of utilising the farm feed resources rather than manipulating stocking rate.
29
Brown, TH, GE Ford, DW Miller e I. Beveridge. "Effect of anthelmintic dosing and stocking rate on the productivity of weaner sheep in a Mediterranean climate environment". Australian Journal of Agricultural Research 36, n. 6 (1985): 845. http://dx.doi.org/10.1071/ar9850845.
Testo completoAbstract (sommario):
The effects of nematodiasis on productivity in weaner sheep was measured at Kybybolite Research Centre, South Australia, during 1976-81. Three levels of control were compared at two stocking rates (7.5 ha-1 and 16 ha-1). One group was not treated with anthelmintics, another group was treated every 3 weeks and the third group (Planned) was given five doses of anthelmintics each year: once in October, twice during the hot dry summer and twice during the winter months. The sheep were replaced by weaner sheep at shearing in October each year. The drenching regime of sheep on a particular paddock was the same for all five years. Nematodes, particularly Trichostrongylus spp., had a very large effect on the production of the sheep. The mean annual death rate of the untreated sheep was 22% and 56070, for the low and high stocking rates respectively. The regularly drenched sheep were 9-31% heavier and cut 11-46% more wool than the survivors of the untreated sheep at the low stocking rate. At the high stocking rate the regularly drenched sheep were 17-58% heavier and cut 14-56% more wool than the survivors of the undrenched sheep. The sheep given the Planned drenching program had similar final liveweights each year to the regularly drenched sheep, and in only two years out of five did the regularly drenched sheep produce significantly more wool than the sheep given the Planned program. The effect of drenching on the contamination of wool with faeces, and the resultant effect on the incidence of fly strike, is discussed. There was a significant variation between years in amount of available pasture, and there was generally slightly more pasture available on the Nil drench treatment paddocks.
30
McGregor, B. A., e W. D. English. "Gross margins in Australian mohair enterprises and relationships with farm inputs, productivity and mohair quality". Animal Production Science 50, n. 6 (2010): 573. http://dx.doi.org/10.1071/an09224.
Testo completoAbstract (sommario):
In the absence of financial information on Australian mohair enterprises we aimed to determine the gross margins (per dry sheep equivalent, DSE) and their relationships with farm inputs, productivity and mohair quality in Australian mohair enterprises. Using established Victorian Farm and Sheep Monitor Project protocols we collected data for the financial years 2004–05, 2005–06 and 2006–07 from farmers in south-eastern Australia and made comparisons with data from wool enterprises of similar farm area. Over 3 years the financial returns from mohair exceeded that from wool in terms of $/DSE ($23.0 v. 11.3) and $/ha ($132 v. $116). This result was achieved despite the mohair enterprises grazing their goats far less intensively compared with the grazing intensity of sheep (5.9 v. 10.3–11.1 DSE/ha) and by using far less phosphate fertiliser than used in the wool enterprises (2.2 v. 4.6–6.1 kg P/ha). These differences were counterbalanced by higher prices for mohair compared with fine wool ($13.15/kg v. $8.35/kg clean fibre). Gross margin for the mohair enterprise did not increase as stocking rate increased. Income from mohair sales declined as the proportion of does in the flock increased. Increasing the proportion of does in the flock was associated with a decline in the average price of mohair ($16/kg greasy at 42% does to $8/kg greasy at 83% does in the flock). This decline was closely associated with the increasing proportion of the total amount of mohair coarser than 34.0 µm (either fine hair or hair) plus stained mohair. The variation in profitability between farms indicates significant scope for many mohair enterprises to increase profit. A focus on producing finer quality mohair will increase mohair profitability.
31
Cottle, D., C. A. Gaden, J. Hoad, D. Lance, J. Smith e J. M. Scott. "The effects of pasture inputs and intensive rotational grazing on superfine wool production, quality and income". Animal Production Science 53, n. 8 (2013): 750. http://dx.doi.org/10.1071/an12289.
Testo completoAbstract (sommario):
A farmlet experiment was conducted between July 2000 and December 2006 as part of the Cicerone Project, which sought to enhance the profitability and sustainability of grazing enterprises on the Northern Tablelands of New South Wales, Australia. A self-replacing Merino enterprise was grazed as the dominant livestock enterprise, together with ~20% of the carrying capacity as cattle, on each of three farmlet treatments: higher levels of soil fertility and pasture renovation with flexible rotational grazing over eight paddocks (farmlet A), moderate soil fertility and pasture renovation with flexible rotational grazing over eight paddocks (farmlet B) and moderate soil fertility and pasture renovation with intensive rotational grazing over 37 paddocks (farmlet C). Prior to commencement of the trial, the three 53-ha farmlets were allocated equivalent areas of land based on soil type, slope and recent fertiliser history. This paper describes the effects of the three pasture and grazing management strategies on the production, quality and value of the wool produced per head, per ha and per farmlet. Up until 2001 there were no differences in wool production between farmlets. Thereafter, significant differences between farmlets emerged in greasy fleece weight per head and price received per kg of fleece wool. For example, the clean fleece value averaged over the 2003–05 shearings for all hoggets, ewes and wethers was 1531, 1584 and 1713 cents/kg for farmlets A, B and C, respectively. There were small but significant differences, which varied between sheep class and year, between the farmlets in average fibre diameter and staple length but less so with staple strength. In general, while the differences between farmlets in staple strength varied over time, farmlets A and B tended to have wool with longer staple length and broader fibre diameter than farmlet C and this affected wool value per kg. Differences in wool income per ha between farmlets grew in later years as the farmlet treatments took effect. In spite of farmlet A having a slightly lower wool value per kg, after taking into account its greater fleece weight per head and its higher stocking rate, the total wool income per ha was higher than on either farmlets B or C. The average gross wool income per ha from 2003 to 2005 was $303, $215 and $180 for farmlets A, B and C, respectively. The highest amount of greasy wool produced was in 2004 when 38.2, 26.5 and 21.5 kg/ha was harvested from farmlets A, B and C, respectively. The fibre diameter profiles of 2-year-old ewes showed similar profiles for farmlets A and B but a significantly finer fibre diameter profile for farmlet C ewes due to intensive rotational grazing. However, sheep on all three farmlets produced wool with high staple strength. Multivariate analyses revealed that greasy fleece weight, staple length and staple strength were significantly positively correlated with the proportion of the farm grazed at any one time, and with soil phosphorus, legume herbage and green digestible herbage thus highlighting the significant influence of pasture and soil inputs and of grazing management on wool production and quality.
32
Young, J., P. T. Doyle e P. Booth. "Strip grazing to control wool growth rate of sheep grazing green annual pastures". Australian Journal of Experimental Agriculture 39, n. 3 (1999): 247. http://dx.doi.org/10.1071/ea98143.
Testo completoAbstract (sommario):
We compared strip grazing (SG) as a means of controlling wool growth rate, reducing variation in fibre diameter along the staple, and of carrying more Merino sheep through winter on green annual pastures, with set stocking (SS) in 3 experiments. In experiments 1 and 2, SG involved grazing to a residual feed on offer (FOO) of 400 kg DM/ha with an estimated intake of about 0.8 kg DM/day for each sheep. Treatments commenced after pasture establishment in autumn–winter, with both treatments stocked at 20 wethers/ha until late spring. During spring, average liveweight changes were lower (P<0.01) under SG than SS (55 v. 153 g/day experiment 1; –16 v. 217 g/day experiment 2). Strip grazing, compared with SS, reduced (P<0.01) the variation in wool growth rate and fibre diameter along the staple leading to lower (P<0.01) clean wool weights (3.54 v. 3.94 and 2.97 v. 4.12 kg), but finer (P<0.01) (20.9 v. 22.0 and 19.5 v. 21.5 mm), stronger (P<0.01) (28.6 v. 25.3 and 39.9 v. 35.5 N/ktex) wool. However, there was also an increase in vegetable matter content of the wool. The effects on annual pastures were to increase grass (79 v. 48 and 59 v. 25%) and reduce legume (12 v. 36 and 22 v. 54%) content at the end of spring. In experiment 3, two strip grazing treatments were used: SGl with a residual FOO of about 400 kg DM/ha and a stocking rate of 28 wethers/ha; and SGh with a residual FOO of about 800 kg DM/ha and stocking rate of 14 wethers/ha. The stocking rate for SS was 12 wethers/ha. SGl, following an autumn deferment, enabled a stocking rate of 28 wethers/ha to be sustained through winter without supplementary feeding. This is substantially higher than the district average stocking rate of about 7 sheep/ha. Strip grazing reduced (P<0.01) liveweights at the completion of treatments (SGl 41.9 v. SGh 47.9 v. SS 60.3 kg), reduced (P<0.01) clean wool weights (3.40 v. 3.72 v. 4.54 kg) and mean fibre diameter (19.1 v. 19.0 v. 20.9 m), but increased staple strength (21.3 v. 19.0 v. 16.9 N/ktex). These results are discussed in relation to opportunities to utilise strip grazing in sheep production systems on annual pastures in south-western Australia.
33
Franklin-McEvoy, J., W. D. Bellotti e D. K. Revell. "Supplementary feeding with grain improves the performance of sheep grazing saltbush (Atriplex nummularia) in autumn". Australian Journal of Experimental Agriculture 47, n. 8 (2007): 912. http://dx.doi.org/10.1071/ea06149.
Testo completoAbstract (sommario):
Merino wethers aged 1.5 years grazed a saltland pasture comprising old man saltbush (Atriplex nummularia) with an inter-row of senesced grasses and medic for 6 weeks in autumn, in a cereal–livestock zone with a Mediterranean-type environment in South Australia. The experimental treatments were a control (old man saltbush, SB), supplementation with 250 g/sheep.day barley straw (SB + S), supplementation with 250 g/sheep.day barley grain (SB + G) and supplementation with 250 g/sheep.day barley straw + 250 g/sheep.day barley grain (SB + S + G). The sheep in SB + G finished the experimental period significantly heavier (53.6 kg, P < 0.001) than SB (51.0 kg), SB + S (50.5 kg) or SB + S + G (51.1 kg) animals. Feeding grain also increased length of wool grown daily by 16% and would have increased the value of the sheep by being able to sell them ‘out of season’ when prices are higher. Sheep supplemented with grain alone had a higher liveweight than those provided with grain and straw, a result that cannot be explained but may be associated with altered grazing behaviour. It appears that, while old man saltbush provides sheep with an acceptable intake of protein and minerals, the addition of a cereal grain supplement improves energy balance and optimises rumen protein capture to improve liveweight and wool growth performance.
34
Besier, R. B., e S. C. J. Love. "Anthelmintic resistance in sheep nematodes in Australia: the need for new approaches". Australian Journal of Experimental Agriculture 43, n. 12 (2003): 1383. http://dx.doi.org/10.1071/ea02229.
Testo completoAbstract (sommario):
Sheep worm infections increasingly threaten the profitability of the Australian sheep industry as the prevalence and severity of anthelmintic resistance continues to rise. Field experiments have demonstrated that the use of drenches that are of reduced efficacy due to resistance can reduce wool production by 10% and significantly reduce sheep sale value. The major factor in benzimidazole (BZ) and levamisole (LV) resistance, and in part macrocyclic lactone (ML) resistance in Haemonchus contortus, is considered to be the excessive frequency of treatment. In Ostertagia circumcincta, ML resistance appears to be related chiefly to interactions between the environment and the time of treatment, where resistant worms surviving drenches are not significantly diluted by worms acquired after treatment. Resistance to the BZs and LV affects almost all Australian sheep farms, and on most drench efficacy is now below a useful level. ML resistance is common in O. circumcincta in Western Australia, and increasingly prevalent in H. contortus in summer rainfall regions. Closantel resistance is a major threat to H.�contortus control in northern New South Wales and southern Queensland. The organophosphate naphthalophos, especially when used in combination with other compounds, has proved useful although variable in efficacy. It is essential that the sheep industry adopts approaches that minimise reliance on chemical control, such as the breeding of worm resistant sheep, use of specific grazing strategies for worm control and apply flock treatment tactics to minimise further resistance development. New non-chemical technologies under development are also expected to contribute to more sustainable worm control. Nutritional regimens that minimise the impact of worm infections and enhance the immune response require investigation and integration into sustainable control practices.
35
Edwards, J. E. Hocking, K. J. Copping e A. N. Thompson. "Managing the nutrition of twin-bearing ewes during pregnancy using Lifetimewool recommendations increases production of twin lambs". Animal Production Science 51, n. 9 (2011): 813. http://dx.doi.org/10.1071/an09158.
Testo completoAbstract (sommario):
The effect on ewe and lamb production by differential management of single- and twin-bearing Merino ewes during pregnancy and lactation was examined. The hypothesis that the survival and productivity of single- and twin-born progeny is not affected by differential management of single- and twin-bearing ewes was tested. To test this hypothesis, two ewe flocks were monitored on a commercial property in the south-east of South Australia. The body condition score of one flock of ewes was managed according to Lifetimewool recommendations for southern Australian (Lifetimewool flock; n = 464). Lifetimewool recommendations are that body condition score should be 3.0 at mating and then allowed to decline to an average of 2.7, which is maintained until lambing. Twin- and single-bearing ewes were managed as separate mobs after pregnancy scanning to meet their energy requirements. The second flock was managed similarly to the commercial ewe flock and was representative of ewe management practices in the region (normal-practice flock; n = 464). At lambing, the condition score of the Lifetimewool flock was 0.7 condition scores units greater than the normal-practice flock. Ewe clean fleece weight and fibre diameter were greater in the Lifetimewool flock and their lambs had higher survival rates to weaning. Over three shearings, progeny from Lifetimewool ewe flocks produced more clean wool (P < 0.0001) but there was no consistent effect on fibre diameter, staple length or staple strength. Twin-born lambs from ewes managed to Lifetimewool guidelines had a similar liveweight and produced similar quantity and quality of wool to single-born lambs managed to Lifetimewool guidelines, but still suffered higher rates of mortality to weaning. This suggests that it is possible to manage ewes pregnant with twins to ensure that their surviving progeny perform at a level similar to single-born progeny managed under similar targets.
36
Doran-Browne, Natalie, Mark Wootton, Chris Taylor e Richard Eckard. "Offsets required to reduce the carbon balance of sheep and beef farms through carbon sequestration in trees and soils". Animal Production Science 58, n. 9 (2018): 1648. http://dx.doi.org/10.1071/an16438.
Testo completoAbstract (sommario):
The sustainability of farming is important to ensure that natural resources remain available into the future. Ruminant livestock production generates more greenhouse gas emissions than other types of agricultural production and most livestock mitigation options to date have a modest greenhouse gas reduction potential (<20%). Trees and soils, by comparison, can sequester large amounts of carbon depending on the availability of land. Previous studies on carbon neutral livestock production have shown that farms with a stocking rate of 8 dry sheep equivalents (DSE)/ha can be carbon neutral or carbon positive by sequestering more carbon than is emitted from the farm. However, the carbon offsets required by farms with higher stocking rates (>20 DSE/ha) has yet to be studied in Australia. The challenge is to sequester enough carbon to offset the higher level of emissions that these higher stocked farms produce. This study calculated the carbon balance of wool, prime lamb and beef enterprises using a range of stocking rates (6–22 DSE/ha) and levels of tree cover in two agroecological zones. Emissions from livestock, energy and transport were offset by the carbon sequestered in trees and soils. Additionally, the carbon balance was calculated of a case study, Jigsaw Farms, an intensive sheep and beef farm in south-eastern Australia. The methods used to calculate emissions and carbon stocks were from the Australian National Greenhouse Gas Inventory. The majority of stocking rates were carbon positive over a 25-year period when 20% of the sheep or beef enterprises were covered with trees. This study demonstrated that substantial reductions can be made in greenhouse gas emissions through the use of carbon sequestration, particularly in trees. The results showed that from 2000 to 2014 Jigsaw Farms reduced its emissions by 48% by sequestering carbon in trees and soil. The analysis of different stocking rates and tree cover provides an important reference point for farmers, researchers and policy analysts to estimate the carbon balance of wool, prime lamb and beef enterprises based on stocking rate and the area of tree cover.
37
Rogers, George E., Andrew Miller e David A. D. Parry. "Robert Donald Bruce Fraser 1924–2019". Historical Records of Australian Science 31, n. 2 (2020): 157. http://dx.doi.org/10.1071/hr19015.
Testo completoAbstract (sommario):
Robert Donald Bruce (Bruce) Fraser was a biophysicist who gained world-wide distinction for his extensive structural studies of fibrous proteins. Bruce began a part-time BSc degree at Birkbeck College, London, while working as a laboratory assistant. In 1942, aged 18, he interrupted his studies and volunteered for training as a pilot in the Royal Air Force (RAF). He was sent to the Union of South Africa and was selected for instructor training, specialising in teaching pilot navigation. At the end of the war he completed his BSc at King’s College, London, and followed this with a PhD. Bruce studied the structure of biological molecules, including DNA, using infra-red micro-spectroscopy in the Biophysics Unit at King’s led by physicist J. T. Randall FRS. During that time Bruce built a structure for DNA that was close to the Watson-Crick structure that gained them and Maurice Wilkins at Kings College, the Nobel Prize in 1962. In 1952, he immigrated to Australia with his family to a position in the newly formed Wool Textile Research Laboratories at the Commonwealth Scientific and Industrial Research Organisation (CSIRO). Here, Bruce established a biophysics group for research on the structure of wool and other fibrous proteins that flourished until his retirement. Over that period he was internationally recognized as the pre-eminent fibrous protein structuralist world-wide. Having been acting chief, Bruce was subsequently appointed chief of the Division of Protein Chemistry and he remained in that role until he took retirement in 1987.
38
Lunney, Daniel. "Causes of the extinction of native mammals of the Western Division of New South Wales: an ecological interpretation of the nineteenth century historical record". Rangeland Journal 23, n. 1 (2001): 44. http://dx.doi.org/10.1071/rj01014.
Testo completoAbstract (sommario):
Twenty-four mammal species – predominantly the medium-sized, ground-dwelling mammals with a dependence on grass/herbs and seeds – disappeared forever from the landscape of the Western Division of New South Wales in a period of 60 years from first settlement in 1841. The present study examines the causes of this extinction episode by constructing a picture of the changing landscape from the historical record and interpreting the findings ecologically. The conclusions point to an extinction process that can be largely attributed to the impact of sheep, an impact that was exacerbated in the scarce and fragile refuges of the flat landscape in times of intense and frequent drought. This conclusion differs from those of many others, particularly Kerin in the Western Lands Review, who pointed to "the impact of feral animals, rather than overgrazing" as the cause of mammal extinctions, and Morton, who considered that the rabbit was "principally (although not entirely)" responsible for mammal extinctions in the rangelands. The rabbit plague in the Western Division from the early 1880s and the influx of foxes in the last years of the 19th century expedited the local demise of some species and even delivered the final blow to surviving remnant populations of a few species of native mammals but they were not the primary agent of extinction. Historical accounts give prominence to the rapidly growing wool industry in the 19th century. From its dominant position as an export commodity, wool became the chief means of the successful spread of colonial settlement. By 1853 there were about 300,000 sheep based at the southern end of the Darling on the watered frontages, which were all taken up by 1858. The west of the Darling was largely occupied by sheep farmers between 1859 and 1876. The history of settlement around Menindee from 1841 can be read as a devastating critique of the failure to realise that the west could not sustain a pattern of land use imposed on it from another world. The deterioration of the pastoral landscape was such that by the late 1880s the "walls of the pastoral fortresses... were beginning to crumble of their own accord, as the foundations on which they were built — the physical environment — altered under stresses...". The sequence of occupation and land use in the Western Division and the timing of the loss of native mammal species allows the conclusion to be drawn that it was sheep, and the way the land was managed for the export wool industry, that drove so many of the mammal species to extinction. The impact of ever-increasing millions of sheep on all frontages, through all the refuges, and across all the landscape by the mid 1880s is the primary cause of the greatest period of mammal extinction in Australia in modern times.
39
Besier, R. B., R. A. Love, J. Lyon e A. J. van Burgel. "A targeted selective treatment approach for effective and sustainable sheep worm management: investigations in Western Australia". Animal Production Science 50, n. 12 (2010): 1034. http://dx.doi.org/10.1071/an10123.
Testo completoAbstract (sommario):
The effectiveness of a targeted selective treatment (TST) approach to the management of sheep worms in adult Merino ewes was compared with a normal worm control program on three properties in south-western Western Australia. For a TST strategy, a proportion of a flock is left undrenched when flock treatments are administered. This establishes a population of worms in refugia, isolated from the effects of anthelmintics, which dilutes the population of worms that survive drenching and, hence, minimises the development of anthelmintic resistance. The main worm genera present in this trial were Teladorsagia and Trichostrongylus. For the TST approach, an initial flock worm egg count was used to determine the proportion of the flock to be drenched at any time, and treatments were then given to that proportion of the flock, with treated individuals identified as those in the poorest body condition. Over a period of 10–12 months, the TST groups on the three properties received 60%, 53% and 73% of the number of drenches administered to the normal treatment groups, in which all sheep were drenched. No clinical signs of parasitism or adverse effects on reproductive indices occurred in the TST groups. Although bodyweight gain and wool weight were ~2 kg and 0.3 kg, respectively, lower in two of the TST groups than in the normal treatment groups, the differences were not significant, and body condition scores of the TST groups were consistently greater than optimal production recommendations. The TST concept has potential as an easily implemented approach to sustainable drench management and would reduce the cost and labour associated with worm control. However, further studies are required to develop decision indices for various environments to ensure a balance between worm control efficiency and sheep production.
40
Johnston, W. H., P. S. Cornish e V. F. Shoemark. "Eragrostis curvula (Schrad.) Nees. complex pastures in southern New South Wales, Australia: a comparison with Medicago sativa L. and Phalaris aquatica L. pastures under rotational grazing". Australian Journal of Experimental Agriculture 45, n. 4 (2005): 401. http://dx.doi.org/10.1071/ea03117.
Testo completoAbstract (sommario):
A grazing experiment conducted in Wagga Wagga (New South Wales) from September 1993 to September 1998 compared the productivity of pastures containing 3 palatable types of summer-active Eragrostis curvula complex, with pastures containing either Medicago sativa or Phalaris aquatica. Issues relating to the management of E. curvula pastures were also investigated. Herbage growth rates of the P. aquatica and M. sativa pastures were highest in winter and spring; E. curvula pastures were most productive in summer and autumn. Stocking rates equivalent to 30–40 dry sheep were carried by the pastures during their growing seasons. Throughout the study, the pastures were dominated by their respective sown perennial species, however, a suite of desirable and undesirable annual grasses and annual legumes usually contributed >20% of total herbage mass in spring. The P. aquatica pasture contained a higher proportion of weedy species than the other pastures, especially C4 grasses and broadleafed species, and towards the end of the experiment it was also invaded by several native perennial grasses. Overall, the wool yield from the M. sativa pasture was 0.5–1.0 kg/animal.year higher than the other pastures. Management to minimise herbage accumulation on the E. curvula pastures was a key issue, and provided that pastures were grazed heavily, this was achieved by the rotational grazing strategy used in the experiment. It was concluded that palatable varieties of E. curvula have a useful and complementary role as perennial pastures in southern Australia. By increasing herbage availability in summer and autumn, E. curvula may improve management flexibility for a wide range of pastures that are commonly grown on farms.
41
Chen, W., J. Scott, G. Blair, R. Lefroy, K. Hutchinson, K. King e C. Harris. "Diet selection and productivity of sheep grazing contrasting pastures". Australian Journal of Agricultural Research 53, n. 5 (2002): 529. http://dx.doi.org/10.1071/ar01091.
Testo completoAbstract (sommario):
A grazing experiment was conducted at the Big Ridge 2 site CSIRO, Chiswick (30˚31′S, 151˚39′E), 20 km south of Armidale, New South Wales, Australia. The site was established in 1955. In March 1966, phalaris and white clover were sown and pastures were fertilised annually with superphosphate until 1993. There were 3 pasture treatments, each with 2 replicates: degraded pasture (low phalaris content), phalaris-dominant, and phalaris–white clover. The effect of pasture type on animal production (liveweight gain and wool) was only significant in 1996, when there were large differences in pasture composition and production between the 3 pasture types. n-Alkane based estimates showed that pasture degradation affected diet selection and nutrient intake and thus sheep production. The estimates in this study also showed no clear preference for a single pasture species over time and lack of strong preferential selection for clovers when sheep were grazing 3 contrasting pastures. Preferential selection of a particular species varied over time depending on the presence and availability of alternative species. Although there were large differences in total N and S intake and faecal output between the 3 pastures, the proportion of the dietary nutrient used for production was similar. This observation reveals the importance of further improving pasture and grazing management, particularly in productive phalaris–white clover pasture with high nutrient flux, to improve nutrient recycling through plant uptake and retention by animals in the grazing ecosystem, and reduce losses.
42
Hill, William G. "Merino Improvement Programs in Australia. Proceedings of a National Symposium, Leura, New South Wales 1987. Supervising editor, B. J. McGuirk. Australian Wool Corporation, Melbourne. 535 pages. ISBN 0 642 115311". Genetical Research 53, n. 1 (febbraio 1989): 72. http://dx.doi.org/10.1017/s0016672300027890.
Testo completo
43
Godfrey, Sosheel S., Thomas Nordblom, Ryan H. L. Ip, Susan Robertson, Timothy Hutchings e Karl Behrendt. "Drought Shocks and Gearing Impacts on the Profitability of Sheep Farming". Agriculture 11, n. 4 (18 aprile 2021): 366. http://dx.doi.org/10.3390/agriculture11040366.
Testo completoAbstract (sommario):
The resilience and profitability of livestock production in many countries can be impacted by shocks, such as drought and market shifts, especially under high debt levels. For farmers to remain profitable through such uncertainty, there is a need to understand and predict a farming business’s ability to withstand and recover from such shocks. This research demonstrates the use of biophysical modelling linked with copula and Monte Carlo simulation techniques to predict the risks faced by a typical wool and meat lamb enterprise in South-Eastern Australia, given the financial impacts of different debt levels on a farming business’s profitability and growth in net wealth. The study tested five starting gearing scenarios, i.e., debt to equity (D:E) ratios to define a farm’s financial risk profiles, given weather and price variations over time. Farms with higher gearing are increasingly worse off, highlighting the implications of debt accumulating over time due to drought shocks. In addition to business risk, financial risk should be included in the analyses and planning of farm production to identify optimal management strategies better. The methods described in this paper enable the extension of production simulation to include the farmer’s management information to determine financial risk profiles and guide decision making for improved business resilience.
44
Johnston, W. H., P. S. Cornish, T. B. Koen e V. F. Shoemark. "Eragrostis curvula (Schrad.) Nees. complex pastures in southern New South Wales, Australia: a comparison of Eragrostis curvula cv. Consol and Medicago sativa L. cv. Nova under intensive rotational management". Australian Journal of Experimental Agriculture 45, n. 10 (2005): 1255. http://dx.doi.org/10.1071/ea04080.
Testo completoAbstract (sommario):
The productivity, carrying capacity and liveweight performance of wether sheep grazing pastures of Eragrostis curvula cv. Consol and Medicago sativa cv. Nova, which were also sown with annual grasses and Trifolium subterraneum, were compared under an intensive 4-paddock rotational grazing regime in a ‘put-and-take’ grazing experiment at Wagga Wagga, New South Wales from November 1993 to August 1996. The productivity of the pastures was broadly similar, with production peaks of >1000 kg/ha in winter and >3000 kg/ha in spring and summer in paddocks that had been spelled for 6 weeks. Although annual species contributed a high proportion of the total herbage mass in spring, over the remainder of the year, both pastures were dominated by their respective perennials. E. curvula maintained an average plant density of approximately 20 plants/m2. The density of M. sativa declined noticeably during the 3 years, and at the end of the experiment M. sativa plants in 1 replicate of the experiment were killed by rising groundwater and dryland salinity. The long-term average stocking rate of E. curvula and M. sativa pastures were similar (12.1 v. 12.5 sheep/ha) and both pastures were capable of sustaining high stocking rates for lengthy periods in spring and summer. Sheep grazing M. sativa tended to be heavier than animals grazing E. curvula, and they produced, on average, 1.1 kg (or 21%) more wool. However, M. sativa was more difficult to establish and its costs for weed and insect control were higher. Therefore, although it was more productive, it might not have been the most economically viable of the 2 pastures. The implications of the findings were discussed within a whole-farm context and it was concluded that E. curvula has a complimentary role to M. sativa for sowing on landscapes and in situations to which M. sativa is poorly adapted.
45
McGrath, S. R., R. Behrendt, M. A. Friend e A. D. Moore. "Utilising dual-purpose crops effectively to increase profit and manage risk in meat production systems". Animal Production Science 61, n. 11 (2021): 1049. http://dx.doi.org/10.1071/an20495.
Testo completoAbstract (sommario):
Dual-purpose cropping (sowing crops with the intention of both grazing them during vegetative growth and harvesting grain thereafter) has become a widespread farming practice in southern Australia. This synopsis paper integrates research from a multi-institutional research project conducted at three nodes located near Hamilton (south-western Victoria), Wagga Wagga (southern NSW) and Canberra (ACT), and sets out 11 principles for the effective utilisation of dual-purpose crops in meat production systems to increase profit and manage risk. Dual-purpose crops can be used to overcome feed quality gaps in late summer–autumn or feed quantity gaps in late autumn/winter. They provide large quantities of high-quality forages for grazing in summer, autumn and winter and can provide a substantial contribution to the annual number of grazing days on a farm. Utilisation of the high-quality dry matter provided by dual-purpose crops is most effective when directed at young growing stock for sale or future reproduction rather than reproducing adult ewes. For example, sale weight of yearlings per ewe was increased by 16% in systems at the Canberra node when dual-purpose crops were prioritised for grazing by weaners. Wool production was also increased in systems that included grazing of dual-purpose crops. Grazing crops in winter does not necessarily reduce supplementary feeding costs for winter or spring lambing. Modelling suggests that inclusion of dual-purpose crops does not substantially change the optimum time of lambing for sheep meat systems. Financial analysis of the experimental data from the Canberra node showed that although cash expenses per hectare were increased in the crop-grazing systems, the overall profitability of those systems over the life of the experiment was greater by AU$207/ha.year than that of the pasture-only system. Factors driving improved profitability included income from grain, higher income from meat and wool, and lower supplementary feeding costs. However, increasing the area sown to crop from 10% to 30% of the farm area in this Southern Tablelands system appeared to increase risk. In south-western Victoria, spring-sown canola carried risk similar to or less than other options assessed to achieve ewe-lamb mating weight. It is likely that at least part of the reduction in risk occurs through the diversification in income from the canola produced as part of the system. It was concluded that the grazing of cereal and canola crops for livestock production can be profitable and assist in managing risk.
46
Wiedemann, S. G., M. J. Yan e C. M. Murphy. "Resource use and environmental impacts from Australian export lamb production: a life cycle assessment". Animal Production Science 56, n. 7 (2016): 1070. http://dx.doi.org/10.1071/an14647.
Testo completoAbstract (sommario):
This study conducted a life cycle assessment (LCA) investigating energy, land occupation, greenhouse gas (GHG) emissions, fresh water consumption and stress-weighted water use from production of export lamb in the major production regions of New South Wales, Victoria and South Australia. The study used data from regional datasets and case study farms, and applied new methods for assessing water use using detailed farm water balances and water stress weighting. Land occupation was assessed with reference to the proportion of arable and non-arable land and allocation of liveweight (LW) and greasy wool was handled using a protein mass method. Fossil fuel energy demand ranged from 2.5 to 7.0 MJ/kg LW, fresh water consumption from 58.1 to 238.9 L/kg LW, stress-weighted water use from 2.9 to 137.8 L H2O-e/kg LW and crop land occupation from 0.2 to 2.0 m2/kg LW. Fossil fuel energy demand was dominated by on-farm energy demand, and differed between regions and datasets in response to production intensity and the use of purchased inputs such as fertiliser. Regional fresh water consumption was dominated by irrigation water use and losses from farm water supply, with smaller contributions from livestock drinking water. GHG emissions ranged from 6.1 to 7.3 kg CO2-e/kg LW and additional removals or emissions from land use (due to cultivation and fertilisation) and direct land-use change (due to deforestation over previous 20 years) were found to be modest, contributing between –1.6 and 0.3 kg CO2-e/kg LW for different scenarios assessing soil carbon flux. Excluding land use and direct land-use change, enteric CH4 contributed 83–89% of emissions, suggesting that emissions intensity can be reduced by focussing on flock production efficiency. Resource use and emissions were similar for export lamb production in the major production states of Australia, and GHG emissions were similar to other major global lamb producers. The results show impacts from lamb production on competitive resources to be low, as lamb production systems predominantly utilised non-arable land unsuited to alternative food production systems that rely on crop production, and water from regions with low water stress.
47
Trompf, J. P., P. W. G. Sale, G. Saul, J. Shovelton e B. Graetz. "Changes in practices and decisions resulting from the paired-paddock model used in the Grassland’s Productivity Program". Australian Journal of Experimental Agriculture 38, n. 8 (1998): 843. http://dx.doi.org/10.1071/ea98058.
Testo completoAbstract (sommario):
Summary. A detailed survey was undertaken in the spring of 1995 with 20 wool producers in south-west Victoria and the south-east of South Australia to determine the impact of their participation for 18 months in a program called the Grassland’s Productivity Program. This program involved groups of producers establishing paired-paddock comparisons on their own farms with guidance from an experienced facilitator. Productive pasture practices (increased fertiliser rates, responsive pasture species and high stocking rates) were used in one paddock, while the remaining paddock was managed with existing practices. A second group of 15 producers from the same districts who did not participate in the Grassland’s Productivity Program were selected at random and also surveyed. Although the 2 groups of producers had similar pasture productivity parameters (phosphorus fertiliser, stocking rates and pasture resowing rates) in the autumn of 1993, the Grassland’s Productivity Program participants had significantly (P<0.05) increased phosphorus fertiliser rates on average from 5.7 to 10.5 kg P/ha, stocking rates from 9.4 to 10.7 dse/ha, and the area of the farm that was being resown to new pasture from 2.9 to 4.0%, by the spring of 1995. There was no change in the pasture practices of the non- Grassland’s Productivity Program producers over this period. The Grassland’s Productivity Program participants also increased their use of soil testing and plant tissue testing and changed their rationale for making fertiliser and stocking decisions. The decisions were now based on an assessment of soil fertility and animal production target levels, together with accurate assessment of pasture production and animal requirements, rather than on past experiences and normal district practices. The increased adoption of the productive pasture technology (practice change) was directly related to a change in attitude to decision making. This change in attitude or beliefs among Grassland’s Productivity Program participants was a result of the action learning experiences that disposed or modified existing beliefs, while integrating the productive pasture technology in a contextualised manner. The paired-paddock approach to learning enabled each participant to witness the productive pasture technology perform on their own farm, in direct comparison with the existing management approach. The participants developed increased confidence in their ability to manage this technology from group-learning experiences, which occurred at regular group meetings.
48
Levot, G. W. "Effective remediation of diazinon from spent sheep dip wash by disposal on land". Australian Journal of Experimental Agriculture 47, n. 1 (2007): 13. http://dx.doi.org/10.1071/ea05361.
Testo completoAbstract (sommario):
Spent sheep dip wash (about 3500 L) containing 59 mg diazinon/L was evenly distributed onto a 450-m2 grassed, soil-bunded, sloping site near Cumnock in central New South Wales, Australia. The entire volume was contained within the bunded area but surface run-off created ponding in the lowest corner of the site. The mean concentration within the top 7 cm of soil was 2.32 mg/kg a day after application. By day 14, this had dropped to 0.4 mg/kg and by day 56, was below the limit of quantification (0.1 mg/kg). The half-life of diazinon in soil was estimated to be 7 days. Residues in the next 7 cm of soil depth were much lower and were below the limit of quantification in all samples collected at day 28 or later. This suggests that vertical leaching of diazinon within the soil profile did not occur despite more than 95 mm of rain during the trial interval. Throughout the 56-day trial interval, diazinon concentrations in the top 7 cm of soil 3 m downhill of the lowest corner of the dip disposal site were unchanged from background pre-treatment levels. No diazinon was detected in samples at 7–14 cm depth in the soil profile in this area. With neither vertical nor lateral movement of diazinon away from the initial treatment zone, we consider the disposal of spent diazinon sheep dips as described here, to be an acceptable and convenient option for Australian wool producers and dipping contractors. Suitable dip disposal sites should be situated away from sensitive locations in areas that have good grass cover over deep soil and that are contained by an effective bund. Stock and other animals should be excluded from these sensitive locations.
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Badgery, W. B., G. D. Millar, D. L. Michalk, P. Cranney e K. Broadfoot. "The intensity of grazing management influences lamb production from native grassland". Animal Production Science 57, n. 9 (2017): 1837. http://dx.doi.org/10.1071/an15866.
Testo completoAbstract (sommario):
The intensity of grazing management required for optimal pasture and animal production from heterogeneous native grasslands has received little research in the high-rainfall zone of south-eastern Australia. The aim of this experiment was to determine how the intensity of grazing management, from continuous grazing (P01) to flexible 4- and 20-paddock rotational systems (P04 and P20), influenced the productivity and sustainability of a Merino ewe, terminal sire lamb production system run on a native grassland dominated by Microlaena stipoides and Rytidosperma spp. The present paper focuses on the animal production and feed-quality results from this experiment. There was a higher per head animal production for the P01 than the P20, with the P04 being intermediate. The differences were found for ewe liveweight and fat score, lamb growth rates and lamb liveweight at weaning. The P20 was able to run higher ewe numbers, in response to greater feed on offer than for P04 and P01, which enabled lamb production per hectare at weaning to be similar and greasy wool production per hectare to be greater than for P01. The organic matter digestibility of the ewe diet estimated from faecal analysis was lower for P20 and P04 systems than for P01 over a 7-month period and explained differences measured in sheep performance at that time. When lambs were retained after weaning, they could be kept for longer on the P20 and grown to a greater weight than for the P01 and P04, but the criteria for setting stocking rates and selling lambs from systems influenced the production from the systems. Further work is needed to investigate the interaction between stocking rate (ewe numbers and lamb sale time) and grazing management and examine different options for managing rotational grazing systems.
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Scott, J. M., K. Behrendt, A. Colvin, F. Scott, L. M. Shakhane, C. Guppy, J. Hoad et al. "Integrated overview of results from a farmlet experiment which compared the effects of pasture inputs and grazing management on profitability and sustainability". Animal Production Science 53, n. 8 (2013): 841. http://dx.doi.org/10.1071/an12284.
Testo completoAbstract (sommario):
The Cicerone Project conducted a grazed farmlet experiment on the Northern Tablelands of New South Wales, Australia, from July 2000 to December 2006, to address questions raised by local graziers concerning how they might improve the profitability and sustainability of their grazing enterprises. This unreplicated experiment examined three management systems at a whole-farmlet scale. The control farmlet (farmlet B) represented typical management for the region, with flexible rotational grazing and moderate inputs. A second farmlet (farmlet A) also used flexible rotational grazing but had a higher level of pasture renovation and soil fertility, while the third farmlet (farmlet C) had the same moderate inputs as farmlet B but employed intensive rotational grazing. The present paper provides an integrated overview of the results collated from component papers and discusses the inferences that can be drawn from what was a complex, agroecosystem experiment. The measurements recorded both early and late in the experiment were tabulated for each of the farmlets and compared with each other as relative proportions, allowing visual presentation on a common, indexed scale. Because of equivalent starting conditions, there was little difference between farmlets early in the experimental period (2000–01) across a wide array of measured parameters, including herbage mass, potential pasture growth rate, liveweight, wool production per head, stocking rate, gross margin and equity. Although the experiment experienced drier-than-average conditions, marked differences emerged among farmlets over time, due to the effects of treatments. During the latter half of the experimental period (2003–06), farmlet A showed numerous positive and a few negative consequences of the higher rate of pasture renovation and increased soil fertility compared with the other two farmlets. While intensive rotational grazing resulted in superior control of gastrointestinal nematodes and slightly finer wool, this system had few effects on pastures and no positive effects on sheep liveweights, wool production or stocking rate. Whereas farmlet A showed higher gross margins, it had a negative and lower short-term cash position than did farmlets B and C, due largely to the artificially high rate of pasture renovation undertaken on this farmlet during the experiment. Although farmlet B had the highest cash position at the end of the experiment, this came at a cost of the declining quality of its pastures. Modelling of the farmlet systems allowed the results to be considered over the longer timeframes needed to assess sustainability. Thus, returns on investment were compared over realistic amortisation periods and produced outcomes based on long-term climatic expectations which were compared with those that arose under the drier-than-average conditions experienced during the experimental period. The main factors responsible for lifting the productivity of farmlet A were the sowing of temperate species and increased soil fertility, which enhanced the amount of legume and increased pasture quality and potential pasture growth. The factor that affected farmlet C most was the low proportion of the farmlet grazed at any one time, with high stock density imposed during grazing, which decreased feed intake quality. The paper concludes that more profitable and sustainable outcomes are most likely to arise from grazing enterprises that are proactively managed towards optimal outcomes by maintaining sufficient desirable perennial grasses with adequate legume content, enhancing soil fertility and employing flexible rotational grazing.