Articoli di riviste: "Wool Australia Quality"

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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.

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Abstract (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.

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Butler, LG, e GM Head. "Photoperiodic rhythm of wool growth and its contribution to seasonal wool production by the Merino, Polwarth, and their reciprocal crosses in southern Australia". Australian Journal of Experimental Agriculture 34, n. 3 (1994): 311. http://dx.doi.org/10.1071/ea9940311.

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Abstract (sommario):

Twelve wethers of each of the Merino and Polwarth breeds and their reciprocal crosses were fed at1 of 2 levels in individual pens for 14 months. Periodic clean wool weight, yield, fibre diameter, and the coefficient of variation (CV%) for fibre diameter were measured from midside patches harvested every6 weeks.There was a significant effect of time of wool harvest on clean wool weight per cm2, yield, fibre diameter(all P<0.01), and its CV% (P<0.05). A trough in wool production occurred about August-September and a peak in January. The amplitude of the photoperiodic rhythm of wool growth (difference between maximum and minimum wool growth per cm2 per 42 days as a percentage of the average) was 40%. Yield also displayed a substantial photoperiodic rhythm, but that of fibre diameter was less pronounced. Mean staple strength was 32.3 N/ktex, the mean break occurring at a distance of 60% of the staple length from the tip; there was no effect of genotype or level of feeding. From comparison with published Tasmanian field data, the seasonal wool growth pattern of sheep at pasture appears similar to the photoperiodic rhythm but occurs about a month earlier. It was concluded that the photoperiodic rhythm of wool production of Tasmanian Merino-based breeds should not be a barrier to manipulation of wool quality (staple strength and fibre diameter) by nutritional management.

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Croker, KP, MA Johns, SH Bell, GA Brown e JF Wallace. "The influence of vaccination with Fecundin and supplementation with lupin grain on the reproductive performance of Merino ewes in Western Australia". Australian Journal of Experimental Agriculture 30, n. 4 (1990): 469. http://dx.doi.org/10.1071/ea9900469.

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Abstract (sommario):

The reproductive performances of groups of 4-6-year-old medium wool Merino ewes that were vaccinated with Fecundin and/or fed sweet lupin grain prior to and during the early part of the joining period were compared with untreated ewes over 2 years. The rams were joined with the ewes in early January of each year. In both years the Fecundin and lupin treatments increased ovulation rates (between 0.13 and 0.56) and the incidence of multiple pregnancies (between 1 and 36%). The proportions of lambs born following treatment with Fecundin were larger than those from the ewes fed only lupins. When the treatments were combined, there were no increases in lambs born above that of Fecundin alone. Pregnancy significantly depressed wool production from individual ewes, while those with more than 1 lamb produced less wool than those with only 1 lamb. However, the average quantity (4.6 kg greasy) and quality of wool produced by the ewes each year was similar for all groups, indicating that the variation in the incidence of multiple pregnancies had not affected flock wool production. The average rate of growth of the progeny from marking to weaning was also similar for each group (191 and 238 g/head.day for years 1 and 2, respectively) even though there were more multiple-born lambs in the Fecundin-treated groups. On a flock basis, it would appear that the nutritional conditions experienced during this study were adequate to avoid significant penalties associated with multiple pregnancies.

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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.

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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.

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McGregor, B. A. "Influence of stocking rate and mixed grazing of Angora goats and Merino sheep on animal and pasture production in southern Australia. 3. Mohair and wool production and quality". Animal Production Science 50, n. 3 (2010): 168. http://dx.doi.org/10.1071/an09186.

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Abstract (sommario):

The effects of animal species (AS; Angora goats, Merino sheep, mixed-grazed goats and sheep at the ratio of 1 : 1) and stocking rate (SR; 7.5, 10 and 12.5 animals/ha) on fibre production and quality were determined in a replicated experiment on improved annual temperate pastures in southern Australia from 1981 to 1984. Separately grazed sheep produced the most total clean fibre/ha at each SR. Mixed-grazed treatments produced amounts of clean fibre/ha similar to the arithmetic mean of sheep and goat treatments at 7.5/ha (21.9 versus 21.3 kg/ha), 10% more at 10/ha (28.3 versus 25.3 kg/ha, P < 0.05) and 7% more at 12.5/ha (31.6 versus 29.6 kg/ha, P < 0.10). Clean wool production/head was affected by AS and SR but not year. Clean mohair production was affected by SR and year but not AS. Variation in mean fibre diameter (MFD) accounted for 67 and 71%, respectively, of the variation in clean wool and clean mohair production/head. There was an AS × SR interaction for clean fibre production/t pasture. Growth rate of mohair was highest in autumn and least in summer. In each season, an increase in the SR reduced the clean mohair growth rate. Growth rate of wool was highest in spring and least in summer. Wool and mohair MFD were affected by an AS × SR interaction. Mohair MFD was also affected by year and season. At 10/ha, wool from mixed-grazed sheep had a greater MFD than wool from separately grazed sheep (20.2 versus 18.9 μm) and mixed-grazed goats grew mohair 1 μm coarser than separately grazed goats. At 12.5/ha mixed-grazed goats grew mohair 1.9 μm finer than separately grazed goats. Mohair MFD was predicted by a multiple regression that included average liveweight for the period of fleece growth, season of growth (summer 1 µm finer than winter) and year (range 1.27 µm). Mohair MFD increased 4.7 µm/10 kg increase in average fleece-free liveweight (P = 6.4 × 10–14). Fleece-free liveweight alone accounted for 76.4% of the variation in mohair MFD. There was an AS × SR interaction for the incidence of kemp and medullated fibres; under severe grazing pressure their incidence was suppressed. This experiment indicated that the principles associated with the effects of SR on wool production on annual temperate pastures apply to mohair production. Mixed grazing of Merino sheep and Angora goats produced complementary and competitive effects depending on the SR. Angora goats should not be grazed alone or mixed-grazed with sheep on annual temperate pastures at SR greater than that recommended for Merino sheep.

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Li, G. D., K. R. Helyar, M. K. Conyers, L. J. C. Castleman, R. P. Fisher, G. J. Poile, C. J. Lisle, B. R. Cullis e P. D. Cregan. "Pasture and sheep responses to lime application in a grazing experiment in a high-rainfall area, south-eastern Australia. II. Liveweight gain and wool production". Australian Journal of Agricultural Research 57, n. 10 (2006): 1057. http://dx.doi.org/10.1071/ar05299.

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Abstract (sommario):

‘Managing Acid Soils Through Efficient Rotations (MASTER)’ is a long-term pasture–crop rotation experiment commenced in 1992. One of the objectives was to demonstrate the extent of crop, pasture, and animal responses to lime application on a typical acidic soil in the 500–800 mm rainfall zone of south-eastern Australia. Two types of pastures (perennial v. annual pastures) with or without lime application were established in 1992. Fifteen- to eighteen-month-old Merino hoggets were used as test animals and were changed annually. This paper reports the results of sheep responses to liming from the 4 continuous pasture treatments over 6 years from 1992 to 1997. The stocking rate was the same on all plots within a treatment during each rotation period, but was varied between treatments based on the pasture availability and sheep body condition. The most important findings from this study are that the limed treatments carried 29% and 27% more stock (up to 4 DSE/ha) than the unlimed treatments for perennial and annual pastures, respectively. As a result, the limed perennial pastures produced 27% more liveweight gain (62 kg/ha.year) and 28% more greasy wool (13 kg/ha.year) than unlimed perennial pastures, whereas the limed annual pastures produced 34% more liveweight gain (77 kg/ha.year) and 24% more greasy wool (11 kg/ha.year) than unlimed annual pastures. The significant responses to lime in liveweight and wool production were detected from the second growing season after the pastures were established. The increased sheep productivity on the limed treatment was due to a combination of increased pasture production and improved pasture quality. Perennial pastures showed a slight advantage in wool production, but not in liveweight gain. However, the seasonal variation of liveweight was greater on annual pastures than on perennial pastures. The larger variation in liveweight change could lead to more adverse effects on wool quality especially at high grazing pressures. Grazing management can be used to manipulate pasture and animal productivity to increase profits from lime use.

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Norman, Hayley C., David G. Masters, Allan J. Rintoul, Matt G. Wilmot, Vijay Jayasena, Angelo Loi e Clinton K. Revell. "The relative feeding value of a new pasture legume, eastern star clover (Trifolium dasyurum), compared with subterranean clover (Trifolium subterraneum)". Australian Journal of Agricultural Research 56, n. 6 (2005): 637. http://dx.doi.org/10.1071/ar04271.

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Abstract (sommario):

An accession of eastern star clover (Trifolium dasyurum C. Presl.), a new species to agriculture, has been identified by the National Annual Pasture Legume Improvement Program for commercial release in Australia. This paper reports the findings of an experiment designed to assess the feeding value of eastern star clover compared with a commercial cultivar of subterranean clover (T. subterraneum L. cv. Dalkeith). The hypothesis tested in this experiment is that sheep grazing eastern star clover will have similar growth rates, condition scores, and wool production to sheep grazing subterranean clover. Additionally, it is hypothesised that the sheep grazing the different clover species will have similar health and meat quality. The relative feeding value of the 2 clover species was tested using 14-month-old Merino wethers, grazing 8 by 0.5 ha plots (4 of each species). Stocking rates were such that herbage mass availability would not have limited feed intake. Liveweight, wool growth, and animal health were monitored. After 10 weeks of grazing, 2 animals from each plot were slaughtered for sensory analysis of meat. Although there were generally no differences in liveweight change, condition, or wool growth between sheep grazing eastern star or subterranean clovers, sheep in the subterranean clover plots grew faster during the first month of grazing. There were no differences in meat eating quality (tenderness, juiciness, or flavour), animal health, or vegetable matter contamination of wool. The data suggest that the clovers had the same relative feeding value despite herbage mass from the eastern star clover plots having lower in vitro digestibility, crude protein, and higher fibre than herbage mass from the subterranean clover plots. Given that there was a minimum of 1000 kg/ha of herbage mass in the plots, it is likely that sheep gazing the two clovers were able to maintain the same weight by selecting the high quality components of the pasture. Differences in plant quality are associated with differences in reproductive strategies of the clovers.

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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.

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Abstract (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.

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Fogarty, N. M., E. Safari, S. I. Mortimer, J. C. Greeff e S. Hatcher. "Heritability of feed intake in grazing Merino ewes and the genetic relationships with production traits". Animal Production Science 49, n. 12 (2009): 1080. http://dx.doi.org/10.1071/an09075.

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Abstract (sommario):

The feed intake of 1279 mature non-pregnant and non-lactating Merino ewes grazing pasture was estimated by faecal marker dilution methods using rumen controlled-release devices containing chromium sesquioxide capsules. The ewes were from two genetic resource flocks (QPLU$ flock at Trangie in NSW and a Western Australia flock at Katanning) that are representative of the major bloodlines and strains in the Australian Merino population. Pedigree information over several generations was used to genetically link other animals from the resource flocks that had additional production data to allow estimation of genetic correlations between feed intake and production traits with greater accuracy. Data were available for over 16 000 records for growth, wool and reproduction traits from the ewes and their relatives, together with carcass and meat quality traits from over 4000 rams that were slaughtered at ~18 months of age. Feed intake of the ewes was significantly affected by the reproductive status of the ewes at their previous lambing and feed intake, expressed as relative digestible dry matter intake (rDDMI), had an estimated heritability of 0.32 ± 0.08. The genetic correlations between rDDMI and growth traits were positive and larger than their standard error for birth (0.24 ± 0.12) and hogget (0.20 ± 0.09) weight, although inclusion of ewe liveweight as a covariate in the model reduced the correlations to close to zero. Generally, the genetic correlations between rDDMI and the wool, reproduction, carcass and meat quality traits were close to zero and smaller than their standard errors, with little effect of including ewe liveweight as a covariate. The results suggest that feed requirements of ewes could be reduced by selection, although ewe weight and growth would also decline unless accounted for in the model. Practical and cost effective methods of measurement of intake under grazing conditions need to be developed.

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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.

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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.

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Kelly, R. W., J. C. Greeff e I. Macleod. "Lifetime changes in wool production of Merino sheep following differential feeding in fetal and early life". Australian Journal of Agricultural Research 57, n. 8 (2006): 867. http://dx.doi.org/10.1071/ar05312.

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Abstract (sommario):

In commercial Merino farming, a major determinant of profitability is quantity and quality of wool production. We tested the hypothesis that the level of feed restriction commonly encountered by autumn/early winter lambing Merino ewes in southern Australia was sufficient to have a detrimental effect on their progeny’s lifetime wool production. Two periods of feed restriction of the dams were tested, viz. from day 50 to 140 of gestation (Expt 1), and from day 50 of pregnancy to weaning at 12 weeks of age (Expt 2). In order to reduce the numbers of experimental animals required, identical twin lambs were produced by cloning embryos. There was a total of 35 and 22 pairs of clones in Expts 1 and 2 that were recorded to 6.4 and 4.4 years of age, respectively. In Expt 1 it was estimated (i.e. conceptus-free weight) that the submaintenance (Sub-M) ewes lost 18 kg in weight compared with 9 kg by the Control (C) ewes over the period of differential feeding. In Expt 2 the Sub-M ewes lost 10 kg during pregnancy and 10 kg during lactation, compared with a loss of 3 kg and a gain of 4 kg over the same period in the C ewes. Gestation length was 1.3 days shorter (P < 0.01) in the Sub-M than C ewes in Expt 1. Birthweights of the Sub-M lambs were 0.5 kg lighter than the C lambs in Expts 1 (P < 0.01) and 2 (P < 0.05). At 12 weeks of age, liveweights of the lambs in the Sub-M and C treatments were 24.2 and 25.9 kg in Expt 1 (P < 0.01) and 14.0 and 25.0 kg in Expt 2 (P < 0.001). Corresponding liveweights at 4 months of age were 30.9 and 32.5 kg (P < 0.01) and 19.9 and 29.7 kg (P < 0.001), the Sub-M animals producing less clean wool (0.1 and 0.4 kg, P < 0.01 and < 0.001, Expts 1 and 2, respectively), that was finer in Expt 2 (2.7 μm, P < 0.001) than their C counterparts. Throughout the rest of the study the Sub-M animals in Expt 2 (but not Expt 1) were on average 3.2 kg lighter (P ranging from < 0.05 to < 0.001) than C animals. In both experiments the ratio of secondary to primary wool-producing follicles was lower (1.1–2.6 units, P < 0.001) in the Sub-M than C animals. These differences led to (P < 0.05) lower significantly adult clean wool production of 0.17 kg (Expt 1) and 0.24 kg (Expt 2) per annum. There was no significant interaction between nutritional treatment and age of the animal for clean wool production. Within experiments there were no significant differences between nutritional treatments in any of the wool quality measurements. However, when fibre diameter data for both experiments were combined for 3.4 and 4.4 years of age, the Sub-M animals were significantly broader (0.3 μm, P < 0.01) when compared with the C animals. We conclude that Sub-M feeding of the pregnant ewe will permanently affect liveweight, the wool follicle population, and wool production and quality, in Merino sheep. Extension of the period of under feeding into lactation (Expt 2) appears to increase the amplitude of the differences in young animals, which is largely overcome by the time the animal reaches 2.4 years of age.

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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.

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Abstract (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.

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Brown, D. J., A. A. Swan, J. S. Gill, A. J. Ball e R. G. Banks. "Genetic parameters for liveweight, wool and worm resistance traits in multi-breed Australian meat sheep. 1. Description of traits, fixed effects, variance components and their ratios". Animal Production Science 56, n. 9 (2016): 1442. http://dx.doi.org/10.1071/an14787.

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Abstract (sommario):

Sheep breeders in Australia that focus on lamb production simultaneously breed sheep that have higher growth rate, improved carcass quality and are resistant to internal parasites. The objective of this study was to estimate genetic parameters for 11 traits recorded in Australian meat sheep, covering liveweight, carcass and internal parasite resistance traits. As the population of meat sheep in this database have become increasingly crossbred this study also investigates the genetic variation within and between breeds. The data comprised 1 046 298 animals from 149 Poll Dorset, 17 Suffolk, 24 Texel and 118 White Suffolk flocks. The results are averages of analyses of 10 datasets constructed by randomly sampling 25% of these flocks. There was considerable genetic variation in all traits analysed: the lowest heritabilities (0.12) were found for weaning weight and the highest heritabilities (0.31–0.32) for eye muscle depth. There were also significant differences between breeds for most traits, which breeders appear to be utilising through crossbreeding. Direct heterosis effects were small and only significant for the liveweight traits ranging from 2% to 3.4% of the phenotypic means. Maternal heterosis was not significant for any trait studied. The inclusion of heterosis effects in the model did not significantly influence the estimated genetic parameters. The results from this study have been used to review the genetic parameters used in the LAMBPLAN routine genetic evaluations conducted by Sheep Genetics.

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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.

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Abstract (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.

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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.

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Abstract (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.

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16

Norman, Hayley C., Angelo Loi, Matt G. Wilmot, Allan J. Rintoul, Bradley J. Nutt e Clinton K. Revell. "Sheep grazing bladder clover (Trifolium spumosum L.) had similar productivity and meat quality to sheep grazing subterranean clover (Trifolium subterraneum L.)". Animal Production Science 53, n. 3 (2013): 209. http://dx.doi.org/10.1071/an12185.

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Abstract (sommario):

An accession of bladder clover, a new species to agriculture, was selected for commercial release in Australia with the cultivar name of AGWEST Bartolo. As part of a duty-of-care assessment, we tested the hypothesis that sheep grazing the bladder clover cultivar will have similar liveweight, condition scores and wool production to sheep grazing a widely adopted subterranean clover cultivar (cv. Dalkeith). Further, we hypothesised that sheep grazing bladder clover and subterranean clover will have similar meat quality (after 48 days of grazing) and health as indicated by muscle, liver and kidney panel analysis. The data supported the hypotheses. While there were significant initial differences in liveweight between the two groups of sheep, there were no significant differences in liveweight at later time points during the grazing period and no significant differences in mean daily growth rate between weighing times. There were no differences in wool growth between sheep grazing the bladder or subterranean clover cultivars. Sheep in the subterranean clover plots had significantly higher condition scores after the first 24 days of grazing; however, these differences were not apparent after another 24 days of grazing. There were some differences in indications of animal health; however, there were no significant detrimental effects associated with bladder clover and sheep grazing both species had mean plasma indicators that were deemed ‘healthy’. There were no differences in meat eating quality as estimated by a consumer panel for tenderness, juiciness or flavour. Dry seasonal conditions limited biomass growth and the sheep were removed from the subterranean clover plots on Day 48 of grazing. The sheep grazing the bladder clover plots remained on the plots for a further 26 days. The data indicate that, for the conditions of this experiment, the clovers had the same relative feeding value. Laboratory analysis of herbage from across the clover plots (bulked before analysis) suggest that the bladder clover had higher in vitro digestibility, crude protein and lower fibre than the herbage sample from the subterranean clover plots. The biomass data indicate that the bladder clover cultivar can support more grazing days per ha in a relatively dry season than the subterranean clover cultivar.

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17

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.

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Abstract (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.

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18

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.

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Abstract (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.

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19

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.

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Abstract (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.

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20

Sahana, G., S. C. Gupta e A. E. Nivsarkar. "Garole: The prolific sheep of India". Animal Genetic Resources Information 31 (aprile 2001): 55–63. http://dx.doi.org/10.1017/s1014233900001486.

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Abstract (sommario):

SummaryA survey on Garole sheep was carried out in the breeding tract for breed characterization. Garole sheep are distributed in the Sundarban region of West Bengal in India. It is a small-sized breed known for its prolificacy and adaptation to the saline marshy land of the Sundarban region. It is believed that these sheep contributed to the prolificacy gene in Booroola Merino sheep of Australia. The breeding tract of Garole sheep falls under the Coastal Saline Zone of West Bengal and the climate of this region is hot and humid. The population of Garole sheep was 206 720 in 1994–1995. This breed is maintained by marginal farmers and landless labourers. Flocks are stationary and average flock size ranges from three to five. They graze on rice fallow land and natural grass cover on the roadsides and water channels. Garole sheep have the ability to graze in knee deep conditions in marshy land. Their colour is generally white. Some animals of black or brown colour are also seen. The male is generally horned and females are polled. They have three distinct types of ears; small, medium and long. Average adult weights in male and females are 15 and 12 kg, respectively. Twin and triplet births are common. The Garole sheep are reared for mutton production. Farmers generally do not shear wool. Fleece is of a coarse quality and is used as bedding material.

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21

Masters, D. G., G. J. Judson, C. L. White, J. Lee e N. D. Grace. "Current issues in trace element nutrition of grazing livestock in Australia and New Zealand". Australian Journal of Agricultural Research 50, n. 8 (1999): 1341. http://dx.doi.org/10.1071/ar99035.

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Abstract (sommario):

Improving trace element nutrition of grazing animals, in a way that is cost effective and that meets consumer perceptions and preferences, is a continuing challenge. This review focuses on research over the past 10 years, addressing issues and perspectives on the roles, risks of inadequacy, and supplementary remedies of key trace elements, both essential and deleterious, which have an impact on the productivity and product quality of grazing livestock throughout Australia and New Zealand. The emphasis is on copper (Cu), cobalt (Co), iodine (I), selenium (Se), and, to a lesser extent, zinc (Zn) — the trace elements most frequently found to be deficient in parts of Australia and New Zealand. Research continues to elucidate new roles for trace elements in the animal, and as this leads to a better understanding of requirements, diagnostic criteria and supplementation strategies need re-evaluation. Newer perspectives on marginal deficiency for Cu, I, Se, and Zn are given and issues for risk management discussed. Advances in sustained delivery of trace elements such as Co (as vitamin B12), I, and Se are reported. The diagnosis and management of marginal Cu deficiency continue to be difficult, especially in New Zealand where recent work has shown that dietary antagonists [iron (Fe), molybdenum (Mo), and sulfur (S)] may impair Cu absorption at lower intakes than previously thought. There is still a dearth of scientific data on the advantages of using so-called organic trace element supplements (metals complexed or chelated with amino acids or peptides). Nevertheless their usage continues to increase. There is increasing evidence that trace elements influence the pathophysiology arising from the ingestion of toxins. This review summarises recent work on the role of Co in annual ryegrass toxicity; Cu, Se, and Zn in lupinosis; Cu and alkaloid toxicity; Zn and facial eczema; and Co and white liver disease. Trace elements are required to support immune function (e.g. as imposed parasite infection) and marginal deficiencies may be exacerbated by an immunological challenge. The roles of Cu, Co, Mo, Se, and, to a lesser extent, chromium and Zn have attracted attention and under conditions of stress there may be an additional need for these elements. Diversification in farming has led to the introduction of species such as deer (Cervus), alpacas (Camilids), emus, and ostriches (Ratites) and the paucity of information on trace element requirements for these species, and also for horses, indicates the need for further work. The effect of supplementation on trace element composition of meat, milk, and wool is also reviewed, both in terms of product characteristics and human health. Of the deleterious elements, cadmium has attracted the most interest and concern because of its introduction into the pastoral system from phosphate-based fertilisers.

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22

Masters, D. G., G. Mata, C. K. Revell, R. H. Davidson, H. C. Norman, B. J. Nutt e V. Solah. "Effects of Prima gland clover (Trifolium glanduliferum Boiss cv. Prima) consumption on sheep production and meat quality". Australian Journal of Experimental Agriculture 46, n. 3 (2006): 291. http://dx.doi.org/10.1071/ea05036.

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Abstract (sommario):

Gland clover (Trifolium glanduliferum Boiss) is a recently introduced and released clover species for use in Mediterranean agricultural systems in southern Australia. There is little information on the expected animal production from this pasture plant although it is known to contain coumarins. Coumarins may have a direct effect on the production of grazing ruminants through a reduction in feed intake and may also have the ability to influence the flavour and odour of meat. In this study, Merino hogget ewes were grazed on eight 0.5 ha replicate plots sown to monocultures of either Prima gland clover or Dalkeith subterranean clover (Trifolium subterraneum ssp. subterraneum L.). The Prima gland clover was estimated to contain between 80 and 300 mg coumarin/kg dry matter. Three sheep were allocated to the plots on 7 September and 1 sheep from each plot was slaughtered on 29 September. Two additional sheep were allocated to the plots on 28 September and another 2 on 19 October. At the end of the experiment on 8 November, each plot contained 2 sheep that had grazed for 3, 6 or 9 weeks. All sheep were slaughtered at this time. The 2 sheep that remained on the plots from 7 September to 8 November were used for the comparison of animal production between the 2 clover species. Following slaughter, measurements were made of carcass characteristics and meat eating quality. The liveweight gain and wool growth of the 2 treatments were similar over the 9 weeks, however, the sheep on the Prima gland clover plots grew faster over the first 3 weeks. The faster growth rate is consistent with a higher in vitro digestibility of the Prima gland clover at this time. The similarity in feeding value of the 2 clover species indicates that there was no depression in feed intake associated with the Prima gland clover. There were some small significant differences in meat eating quality between the groups. Meat from sheep grazing the Prima gland clover was drier and had a more pleasant taste. These differences are unlikely to be large enough to have any commercial significance. The results indicate that the Prima gland clover has a feeding value at least equivalent to the Dalkeith subterranean clover and that, under the conditions of this experiment, the coumarin concentrations in the Prima gland clover are not high enough to affect either feed intake or the flavour and odour of meat.

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23

Nolan, Elizabeth, Terence Farrell, Madeleine Ryan, Candice Gibbon e Fredoun Z. Ahmadi-Esfahani. "Valuing quality attributes of Australian merino wool". Australian Journal of Agricultural and Resource Economics 58, n. 3 (21 ottobre 2013): 314–35. http://dx.doi.org/10.1111/1467-8489.12027.

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24

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.

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Abstract (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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25

Chambers, Paul GS, e Nuno MG Borralho. "A simple model to examine the impact of changes in wood traits on the costs of thermomechanical pulping and high-brightness newsprint production with radiata pine". Canadian Journal of Forest Research 29, n. 10 (1 ottobre 1999): 1615–26. http://dx.doi.org/10.1139/x99-127.

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Abstract (sommario):

A number of functions were investigated that related the costs of thermomechanical pulp (TMP) and high-brightness newsprint production, using Pinus radiata D. Don, to important pulp and paper quality (breeding objective) variables, including specific energy consumption and pulp handsheet tear and tensile strength, brightness, and opacity. Pulp handsheet quality traits were considered to be reasonable two-dimensional predictors of paper quality traits in this context. A specific production process that requires the use of a reinforcement kraft pulp and an artificial clay filler to improve the quality of paper produced from the bleached TMP fibres was investigated, similar to the production process used by Australian Newspaper Mills' Boyer Mill in Tasmania, Australia. Pulp and pulp handsheet quality variables could be explained by significant (P > 0.05) wood traits using multiple linear regression equations. This provided a method to predict the economic importance of each wood trait in relation to the thermomechanical production process investigated. The results showed that tracheid length, wood density, wood brightness, and tracheid coarseness were the best predictors of costs. Increases in tracheid length, wood density, and wood brightness and decreases in tracheid coarseness resulted in decreasing the total costs of TMP and high-brightness newsprint production.

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26

Rowe, J. B. "The Australian sheep industry - undergoing transformation". Animal Production Science 50, n. 12 (2010): 991. http://dx.doi.org/10.1071/an10142.

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Abstract (sommario):

Changes in the sheep industry over the last 20 years represent a trend that is unlikely to be reversed. The farm gate value of wool production has decreased from over $6 billion to ~$2.5 billion and the value of sheep meat has increased from $0.5 to $2.2 billion. Wool and meat are now on an equal footing in terms of the economic value of each sector of the industry. Future profitability of both wool and sheep meat production depends on achieving a high rate of productivity gain and improving quality attributes valued by consumers. Wool and sheep meat cannot compete on price or volume with synthetics and cotton in the textile market or with chicken and pork in the meat market. Differentiation based on quality and consistency needs to be measurable and clearly understood by consumers. The combination of genetic selection and good management can deliver improved productivity gain. Skills development and training will be essential for the industry to fully utilise available knowledge and new technologies.

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27

KULIKOVA, A. YA. "QUALITY OF SHEEP SEED OF MEAT-WOOL BREEDS BY SEASON YEAR". Sheep, goats, wool business, n. 4 (2022): 20–22. http://dx.doi.org/10.26897/2074-0840-2022-4-20-22.

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Abstract (sommario):

In the conditions of the hot climate of the South of Russia, purebred Texel sheep of Australian breeding by the beginning of the main breeding season in sheep breeding in the North Caucasus zone (end of August, fi rst decade of September) have reduced sexual activity, ejaculate volume and unsatisfactory seed quality, compared with Texel sheep of Finnish breeding and Kuban Lincolns. The reproductive ability of texel sheep of Australian breeding is restored at a later date.

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28

Sawyer, Gregory, Dylan Russell Fox e Edward Narayan. "Pre- and post-partum variation in wool cortisol and wool micron in Australian Merino ewe sheep (Ovis aries)". PeerJ 9 (27 aprile 2021): e11288. http://dx.doi.org/10.7717/peerj.11288.

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Abstract (sommario):

An individual merino sheep’s output of wool production is influenced by synergistic interactions of sheep genetics, climate, farm management, and nutrition available to the whole flock. The price paid to the producer for this wool commodity is determined via numerous tested parameters and /or subjective appraisal of the raw greasy wool. This research investigated the level of variation in wool cortisol (a physiological stress biomarker) and wool micron (MIC) in Merino ewes (Ovis aries), pre-partum and post-lambing (lactation/lambs at foot), using maiden ewe (n = 38) managed in an outdoor paddock in a commercial farm. The key findings of this study are; (1) wool quality indicators showed a significant variation between pre- and post- parturition including significant reduction in MIC and (2) there was a negative correlation between wool cortisol levels and wool micron pre-parturition (rs = − 0.179, p < 0.05). This relationship between wool cortisol and wool micron was positive (rs = + 0.29, p < 0.05) during post-parturition suggesting that ewes with lambs at foot ended up with finer wool (reduction in fibre diameter) but they also maintained high levels of wool cortisol. Furthermore, the comfort factor, curvature, standard deviation and spin fineness of the wool were also significantly reduced post-parturition. The results of this study show that metabolic resources partitioning in ewe associated with pregnancy and lambing can result in a reduction in wool quality indices. The activity of the HPA-axis is attenuated during late gestation and parturition as a maternal adaptation; however, the results of our study show that wool cortisol remained similar between pre- and post- lambing. This result indicates that environmental stressors that may have been operating on farm (e.g., cold winter period) could influence on maternal physiological stress response however the exact level of influence of environment conditions on ewe stress levels and productivity traits (e.g., lambing success and wool quality) warrants further investigation. In conclusion, the use of top-knot wool sampling in combination with wool cortisol analysis provides researchers with a convenient method to quantify wool quality and physiological stress simultaneously under commercial sheep production.

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29

Van Beem, D., D. Wellington, B. L. Paganoni, P. E. Vercoe e J. T. B. Milton. "Feed efficiency for meat and wool production by Merino and F1 Dohne×Merino lambs fed pelleted diets of different nutritive value". Australian Journal of Experimental Agriculture 48, n. 7 (2008): 879. http://dx.doi.org/10.1071/ea08063.

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Abstract (sommario):

There is anecdotal evidence from Western Australian breeders that Dohne sheep maintain a higher level of meat and wool production than Australian Merinos. Feed efficiency, carcass and wool attributes are moderately heritable so we hypothesised there would be differences in these traits between Merino and F1 Dohne × Merino lambs. Two groups of 15 Merino and 15 F1 Dohne × Merino wether lambs (29–40 kg) were fed a pelleted diet of either moderate or high energy and protein content for 48 days. Ad libitum pellet intake and liveweight gain were measured and the feed conversion ratio (FCR) for both wool growth and liveweight were calculated. Wool growth and quality were measured and the lambs were slaughtered to measure carcass and meat quality attributes. The F1 Dohne lambs were heavier at the start of the study and grew faster than the Merinos (P < 0.05) irrespective of diet. Consequently, the carcasses of the F1 Dohne lambs were heavier than the Merinos (P < 0.001), but the differences in FCR were not significant. Merino lambs produced more clean wool of lower fibre diameter from less feed than the F1 Dohne lambs (P < 0.05). These results suggest that F1 Dohne × Merino lambs may have an economic advantage in terms of meat production, but this is traded-off against wool production.

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30

James, PJ, RW Ponzoni, JRW Walkley e KJ Whiteley. "Genetic parameters for wool production and quality traits in South Australian Merinos of the Collinsville family group". Australian Journal of Agricultural Research 41, n. 3 (1990): 583. http://dx.doi.org/10.1071/ar9900583.

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Abstract (sommario):

Heritabilities and phenotypic and genetic correlations for fleece traits were estimated from a data set comprising 805 male and female progeny of 44 sires of the Collinsville family group. Characteristics included in the study were greasy and clean fleece weight, yield, mean, standard deviation and coefficient of variation of fibre diameter, resistance to compression, scoured and greasy wool colour (expressed as yellowness, lightness and yellowness index), wax content, suint content, and subjectively assessed scores for greasy colour, character, handle, quality number, condition, staple formation, tip formation and density. Heritabilities of greasy and clean fleece weight, yield, mean fibre diameter and subjectively assessed fleece scores were in broad agreement with estimates from other Merino strains, but the genetic correlations of mean fibre diameter and associated characters (handle, quality number) with clean fleece weight were lower than previous estimates. Heritabilities for scoured yellowness of wool, resistance to compression and coefficient of variation of fibre diameter, which are potential additional measurements for the specification of wool in sale lots, were 0.42 (�. 0.14), 0.57 (� 0.15) and 0.47 ( � 0.15) respectively. Estimated heritabilities of wax and suint content were 0.24 (�0.11) and 0.44 ( � 0.14). Although the phenotypic correlations between measures of greasy wool colour and the corresponding measures of scoured wool colour were low (less than 0.3), the genetic correlations were moderate to high (0.4-0.9). Thus selection on the basis of greasy wool colour should lead to genetic improvements in scoured colour. The genetic correlations of resistance to compression with clean fleece weight and fibre diameter were: 0.46 (�0.21) and 0.44 (� 0.20) respectively, but there were no other strong, unfavourable correlations.

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31

Norton, Mark R., Denys L. Garden, Beverley A. Orchard, Philip Armstrong e Trent Brassil. "Effects of lime, phosphorus and stocking rate on an extensively managed permanent pasture: botanical composition and groundcover". Crop and Pasture Science 71, n. 7 (2020): 700. http://dx.doi.org/10.1071/cp20135.

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Abstract (sommario):

Low phosphorus (P) constrains productivity of many of the permanent pastures of south-eastern Australia where wool and meat production are important. Whereas the need for fertilisation with P is indisputable for many soils, the benefits of liming to ameliorate soil acidification are not always clear in terms of forage production or quality. This experiment, by measuring botanical composition and groundcover over 10 years, aimed to address the issue of forage composition and groundcover. Merino wethers were continuously grazed on a permanent pasture under two stocking rates (low and high) following treatments with three rates of surface-applied lime and two rates of P. The lime rates were: nil, and sufficient to raise the pHCaCl2 of the 0–10 cm soil layer to 5.0 and to 5.5. Phosphorus was added as two rates of single superphosphate: 125 kg ha–1 every 2–3 years, and 250 kg ha–1 every year. Two hypotheses were proposed: (i) as lime application rate increased, it would lead to the pasture swards having a higher percentage of species favourable for grazing animal production, and a higher level of sward groundcover would be maintained; and (ii) legume presence would be favoured by a higher level of applied P over the long term. The Millennium Drought (1997–2008), which coincided with this experiment (1998–2008), tended to mask or reduce lime effects; nevertheless, the higher legume content in the sward, as well as the superior groundcover found in the high lime–high P treatments at various times throughout the experiment and at its completion compared with the nil-lime control, indicated positive forage effects of lime application. Moreover, by the termination of the experiment in 2008, groundcover generally tended to be lower under nil lime than in treatments that had received lime. The higher proportion of legume in the sward was closely linked to greater applied P, although this did not occur at the low stocking rate in the absence of lime. By contrast, similar high P–low stocking rate treatments but with applied lime had the highest clover contents. It is proposed that the poor persistence of the treatment without lime may be due to a combination of poor legume seedset, because of excessive competition from accompanying grasses, and aluminium toxicity adversely affecting legume growth.

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32

Preston, J. W. V., S. Hatcher e B. A. McGregor. "Fabric and greasy wool handle, their importance to the Australian wool industry: a review". Animal Production Science 56, n. 1 (2016): 1. http://dx.doi.org/10.1071/an14777.

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Handle-related properties of woollen fabrics have been demonstrated to be major factors affecting consumer buying attitudes. Handle is the combination of both textural and compressional attributes. Compressional handle has demonstrated processing advantages in woven and knitted fabrics. The handle of processing lots can be manipulated using a variety of technologies but direct manipulation of textural greasy wool handle pre-processing is still crude. On-farm, there is documented evidence that including handle assessment in a selection index provides additional improvements in genetic gain. However, the assessment of greasy wool handle is based on a tactile evaluation of the wool staple by sheep and wool classers, and its application is affected by a lack of framework that instructs assessors on a standard method of assessment. Once a reliable and repeatable protocol is developed, further understanding of the effect greasy wool handle has on final garment quality will be possible.

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33

Midgley, S. J., e J. W. Turnbull. "Domestication and use of Australian acacias: case studies of five important species". Australian Systematic Botany 16, n. 1 (2003): 89. http://dx.doi.org/10.1071/sb01038.

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Some Acacia species native to Australia and neighbouring countries are significant in the rural economy of many countries. Aspects of the domestication process and uses of A. mangium, A. crassicarpa, A. mearnsii, A.�saligna and A. colei are reviewed. Commercial plantations of A. mearnsii in tropical highlands and temperate areas provide high quality tannins for adhesives and leather making and wood for paper pulp, rayon, charcoal and small-utility timbers. Plantations of A. saligna in warm-temperate and semi-arid areas provide stock fodder, soil stabilisation, fuelwood and charcoal. In the humid tropical lowlands of South-east Asia, pulpwood is produced in extensive plantings of A. mangium and in smaller-scale plantations of A. crassicarpa in Indonesia. The human food value of seeds of some dry-zone Australian acacias, such as A. colei, is recognised. Domestication of these and other Australian acacias is at various stages and is influenced by the characteristics of the species, extent of planting and the commercial value of the products. The potential for many acacias to become weeds is recognised. The case studies highlight a number of important aspects in domesticating acacias.

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34

Mortimer, S. I., D. L. Robinson, K. D. Atkins, F. D. Brien, A. A. Swan, P. J. Taylor e N. M. Fogarty. "Genetic parameters for visually assessed traits and their relationships to wool production and liveweight in Australian Merino sheep". Animal Production Science 49, n. 1 (2009): 32. http://dx.doi.org/10.1071/ea08074.

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Abstract (sommario):

Heritability was estimated for a range of visually assessed traits recorded on Merino sheep, together with the phenotypic and genetic correlations among the visually assessed traits and correlations of the visually assessed traits with measured wool production traits and liveweight. Data were derived from four research resource flocks, with a range of 12 958 to 57 128 records from animals with 478 to 1491 sires for the various traits. The estimates of heritability were high for the wool quality traits of handle, wool character and wool colour (0.33–0.34) and the conformation traits of face cover, neck wrinkle and body wrinkle (0.42–0.45), moderate for front leg structure (0.18) and low for back leg structure (0.13). Fleece rot score had low heritability (0.14), while classer grade was moderately heritable (0.20). Estimates of genetic correlations among the visually assessed wool quality traits were low to moderate in size and positive (0.17–0.47). Genetic correlation estimates among the assessed conformation traits were generally very low, except for the genetic correlations between scores for neck and body wrinkle (0.92 ± 0.01) and front and back leg structure (0.31 ± 0.09). Fleece rot score had low positive genetic correlations with neck and body wrinkle scores (0.18 ± 0.05 and 0.15 ± 0.05, respectively) and classer grade (0.26 ± 0.06). Classer grade was slightly positively correlated with the wool quality traits (0.17–0.45) and leg structure traits (0.21–0.25). The genetic correlations among the visually assessed traits were generally neutral to favourable. The visually assessed wool quality traits had low to moderate favourable genetic correlations with mean and coefficient of variation of fibre diameter (0.19 –0.47), but negative correlations with clean wool yield (–0.26 to –0.37). Face cover was unfavourably correlated with staple length (–0.27 ± 0.04) and liveweight (–0.23 ± 0.02). Neck and body wrinkle scores were genetically associated with higher greasy (0.33–0.39) and clean fleece weights (0.19–0.22), greater coefficient of variation of fibre diameter (0.24–0.26) and fibre curvature (0.27–0.28), but with reduced yield (–0.26 to –0.28) and staple length (–0.34 to –0.41). Fleece rot score was genetically correlated with clean fleece weight (0.26 ± 0.05) and coefficient of variation of fibre diameter (0.27 ± 0.04). Classer grade was favourably correlated with greasy and clean fleece weights (–0.41 to –0.43), staple length (–0.29 ± 0.04), liveweight (–0.36 ± 0.03) and coefficient of variation of fibre diameter (0.27 ± 0.03). Most genetic correlations between the visually assessed traits and the measured production traits and liveweight were close to zero and less than 0.2 in magnitude. This study provides accurate values for the parameter matrix required to incorporate visually assessed traits into breeding objectives and the genetic evaluation programs used in the Australian sheep industry, allowing the development of breeding objectives and indexes that optimally combine visually assessed performance and measured production in Merino sheep.

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35

Leggate, William, Chandan Kumar, Robert L. McGavin, Adam Faircloth e Mark Knackstedt. "The effects of drying method on the wood permeability, wettability, treatability, and gluability of southern pine from Australia". BioResources 16, n. 1 (7 dicembre 2020): 698–720. http://dx.doi.org/10.15376/biores.16.1.698-720.

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Abstract (sommario):

Drying has a major impact on the viability of sawn timber production, particularly through its influence on productivity, energy usage, and product quality. Traditionally, plantation-grown southern pine structural grade timber from Australia has been dried using high temperature (≥ 180 °C) conventional batch kilns. However, the Australian industry is showing increasing interest in continuous drying kilns because of reported cost savings and potential improvements in product quality. This study investigated the differences between continuous drying and conventional drying schedules on the radial permeability, wettability, gluability, and treatability of southern pine timber from Queensland plantations. The high temperature drying resulted in significantly lower liquid permeability compared to low temperature drying; however, there were no significant differences between drying schedules for gas permeability. For combined wood surface and core data, there were no significant differences in liquid permeability between low temperature drying and continuous drying or between continuous drying and high temperature drying schedules. For earlywood after surface machining, continuous drying resulted in the greatest wettability (based on K-values), whereas for latewood after surface machining, low temperature drying produced the greatest wettability. Earlywood had greater wettability compared to latewood. Continuous drying resulted in better gluability and treatability compared to conventional drying schedules.

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36

Mortimer, S. I., K. D. Atkins, S. J. Semple e N. M. Fogarty. "Predicted responses in Merino sheep from selection combining visually assessed and measured traits". Animal Production Science 50, n. 10 (2010): 976. http://dx.doi.org/10.1071/an10085.

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Abstract (sommario):

Visually assessed traits for wool quality and ease of management are important to Merino sheep breeders and need to be considered in breeding programs. The present study reports on the predicted correlated responses in visual traits from selection using a range of standard MERINOSELECT™ indices available for use in Australian Merino breeding programs. The effect of including a visual trait in the index is also reported. The visual scored traits were classer grade, wool quality (handle, character and colour), conformation (neck and body wrinkle, front and back leg structure) and fleece rot. The indices covered a range of micron premiums of varying emphasis on increasing fleece weight and reducing fibre diameter. The indices were for Merino wool enterprises (Merino 14%, Merino 7% and Merino 3.5%) and Merino dual purpose wool and meat enterprises (Dual Purpose 7% and Dual Purpose 3.5%). The breeding objectives for the indices included fleece weight, fibre diameter, coefficient of variation of fibre diameter, staple strength, bodyweight and reproduction. Selection over 10 years using the standard MERINOSELECT™ indices is predicted to result in a small correlated improvement in the wool quality traits and classer grade, with a slight deterioration in fleece rot score. The improvement in wool handle, character and colour are greater with those indices that have a greater emphasis on reducing fibre diameter than with those increasing fleece weight. Indices with more emphasis on increased fleece weight than on reduced fibre diameter are predicted to result in small increases in neck and body wrinkle scores and a slight deterioration in wool colour. Inclusion of classer grade, handle, character or colour provided slight extra gains in fleece weight for indices that emphasised reduced fibre diameter through increased accuracy of selection.

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37

Fogarty, N. M., E. Safari, P. J. Taylor e W. Murray. "Genetic parameters for meat quality and carcass traits and their correlation with wool traits in Australian Merino sheep". Australian Journal of Agricultural Research 54, n. 7 (2003): 715. http://dx.doi.org/10.1071/ar03047.

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Abstract (sommario):

Estimates of genetic parameters for carcass traits in Merino sheep are presented, including muscle pH and colour, which are indicators of meat quality. The inclusion of these in the parameter set for genetic evaluation will provide the basis for more accurate estimated breeding values and the design of better breeding programs for improving meat traits in straightbred Merino sheep and crossbred lamb production. Data from 1045, nineteen-month-old Merino rams, the progeny of 125 sires from 3 strains that are representative of the industry, were used. Heritability and genetic correlations were estimated by fitting an animal model using a REML procedure in univariate and multivariate analyses. The traits included fasted pre-slaughter liveweight; dressing %; carcass tissue depth at the GR site (FATGR); fat depth at the C site (FATC); eye muscle depth (EMD), width (EMW), and area (EMA); ultimate pH and colour (L*, a*, b*) of the eye muscle. Multivariate analyses were used to estimate genetic correlations among meat traits and between wool traits (clean wool weight and mean fibre diameter) and selected carcass and meat traits. Estimates of heritability were: liveweight 0.51 (±0.10), dressing % 0.39 (±0.10), FATGR 0.33 (±0.09), FATC 0.20 (±0.08), EMD 0.27 (±0.08), EMW 0.15 (±0.07), EMA 0.23 (±0.08), muscle pH 0.27 (±0.09), and 0.14 (±0.07), 0.02 (±0.06), and 0.04 (±0.06) for the meat colour measurements L*, a*, and b* respectively. There was a favourable genetic correlation between muscle pH and colour L* of –0.56 (±0.23). There were also significant genetic correlations between wool weight and FATGR (–0.34 ± 0.16) and between mean fibre diameter and muscle colour L* (–0.66 ± 0.27). The study indicates that there is genetic variation for carcass traits, including indicators of meat quality, with scope for selection to improve meat production and quality in Merino sheep.

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38

Lakota, E. А. "PRESERVATION OF GENETIC POTENTIAL OF STAVROPOL SHEEP BREED FOR POVOLZHYE DREY STEPPE ZONE". Vestnik of Ulyanovsk state agricultural academy, n. 3(50) (8 settembre 2020): 179–84. http://dx.doi.org/10.18286/1816-4501-2020-3-179-184.

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Abstract (sommario):

In conditions of Povolzhye steppe zone development of productive qualities of Stavropol breed sheep was conducted by meat merino sheep. Experimental research was carried out in ZAO «Novaya Zhizn» in Novouzensky district of Saratov region, located in semi desert zone, bordering upon South-West Khazakhstan. The research aim was the increase and maintenance of genetic potential of Stavropol breed sheep of Povolzhye population. Working procedure is based on guidelines of the All-Union Academy of Agricultural sciences, All Union research institute of sheep and goat breeding. The study materials were Stavropol pure breed sheep and 1/8 –thoroughbred cross breed with Australian meat merino herdmates. As the result of stepped breeding of local Stavropol ewe with half bred by Australian meat merino ram- breeder of Stavropol breed animals of 1/2 ,1/4, 1/8 –blood were obtained, which then one- shear tupped by breeding «inter se». It is proved that in applying such selective method 1/8-blood by Australian meat merino sheep were characterized with higher body weight, better wool quality in contrast to Stavropol pure –breed herdmates. So, in 1/8-blood by Australian meat merino of hybrid ewe during breeding «inter se» live body at birth was higher than at pure breed herdmates for 5,56 %, during ablactation –at the age of 4 months - for 6,38 % (difference isn’t accurate). According to sharing of wool in grease, superiority of ewe of hybrid origin over pure breed was 5,6 % (Р≥0,99), but in terms of washed fiber it increases to 8,3 % (Р≥0,999). So, in dry steppe zone of Povolzhye new improved, according to its productive qualities, genotype of Stavropol breed sheep is created with retention of genetic resource that is essential economic factor for the modern maintenance of fine-wool sheep breeding field.

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39

Brennan, G. K., e P. Newby. "Potential of Western Australian Eastern Goldfields timbers for high quality wood products". Australian Forestry 55, n. 1-4 (gennaio 1992): 74–79. http://dx.doi.org/10.1080/00049158.1992.10676100.

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40

Baltunis, Brian S., Harry X. Wu e Mike B. Powell. "Inheritance of density, microfibril angle, and modulus of elasticity in juvenile wood of Pinus radiata at two locations in Australia". Canadian Journal of Forest Research 37, n. 11 (novembre 2007): 2164–74. http://dx.doi.org/10.1139/x07-061.

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Abstract (sommario):

A total of 1640 increment cores from 343 radiata pine ( Pinus radiata D. Don) families were sampled at two second-generation progeny trials, aged 6 and 7 years, for a detailed genetic study of juvenile wood quality traits. Density, microfibril angle (MFA), and modulus of elasticity (MOE) were determined from pith to bark using SilviScan® technology. Heritability was greatest for area-weighted density at the two sites (0.63 and 0.77, respectively), and the lowest for growth traits (<0.23). Genotype by environment interaction was low for all three wood quality traits. A positive genetic correlation between density and MOE (0.43), and a highly negative, and therefore, favourable genetic correlation between MFA and MOE (–0.92) were observed, implying that improvement of multiple juvenile wood properties is possible. The genetic correlations between whole-core wood quality traits and individual-ring measurements suggest that improvement for juvenile wood properties across the entire profile of the corewood including the innermost rings can be achieved. However, density, MFA, and MOE had unfavourable genetic correlations with diameter growth suggesting that selection for increased density and MOE, and reduced MFA in the absence of selection for growth will result in a genetic loss for growth rate.

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41

Vallejo Adriana, Fernández Abella Daniel, Ramos Zully e Montossi Fabio. "Relationship between skin structure and wool traits for Ultrafine and Dohne Merino sheep of Uruguay". World Journal of Advanced Research and Reviews 12, n. 1 (30 ottobre 2021): 465–72. http://dx.doi.org/10.30574/wjarr.2021.12.1.0553.

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Abstract (sommario):

The demand in the world market for high quality fine and superfine wool is increasing, responding to greater wool textile industry demands and price incentives. There are few research studies focused on hair follicle population in fine and superfine Merino sheep in Uruguay. This study evaluates the association between wool follicle population and the most relevant economical wool traits. This work was carried out on Ultrafine Australian Merino (UAM) and Dohne Merino (DM) animals (lambs and rams). Phenotypic correlations between the secondary/primary follicles (S/P) and other wool traits (fiber diameter, staple length, clean fleece weight, scoured yield, coefficient of variation of fiber diameter and comfort factor parameter, were performed using histological skin cuts. Two skin samples were extracted from each lamb at two and nine months of age. These were processed at the skin histology laboratory to obtain a histological preparation for further biopsy, being able to differentiate the structures obtained to be evaluated. The results showed in the UAM group, S/P ratio in nine-month-old lambs was greater than two-month-old lambs (31.08 vs 23.12 P< 0.05). For DM group, there were no differences in the S/P ratio between age groups. Phenotypic correlations for wool characteristics obtained were of low to medium or null magnitude in both genotypes.

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42

Desservettaz, Maximilien, Frances Phillips, Travis Naylor, Owen Price, Stephanie Samson, John Kirkwood e Clare Paton-Walsh. "Air Quality Impacts of Smoke from Hazard Reduction Burns and Domestic Wood Heating in Western Sydney". Atmosphere 10, n. 9 (17 settembre 2019): 557. http://dx.doi.org/10.3390/atmos10090557.

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Abstract (sommario):

Air quality was measured in Auburn, a western suburb of Sydney, Australia, for approximately eighteen months during 2016 and 2017. A long open-path infrared spectrometer sampled path-averaged concentrations of several gaseous species, while other pollutants such as PM 2.5 and PM 10 were sampled by a mobile air quality station. The measurement site was impacted by a number of indoor wood-heating smoke events during cold winter nights as well as some major smoke events from hazard reduction burning in the spring of 2017. In this paper we compare the atmospheric composition during these different smoke pollution events and assess the relative overall impact on air quality from domestic wood-heaters and prescribed forest fires during the campaign. No significant differences in the composition of smoke from these two sources were identified in this study. Despite the hazard reduction burning events causing worse peak pollution levels, we find that the overall exposure to air toxins was greater from domestic wood-heaters due to their higher frequency and total duration. Our results suggest that policy-makers should place a greater focus on reducing wood-smoke pollution in Sydney and on communicating the issue to the public.

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43

Hogg, A. G., Thomas Higham, Steve Robertson, Roelf Beukens, Tuovi Kankainen, F. G. McCormac, Johannes Van Der Plicht e Minze Stuiver. "Radiocarbon Age Assessment of a New, Near Background Iaea 14C Quality Assurance Material". Radiocarbon 37, n. 2 (1995): 797–803. http://dx.doi.org/10.1017/s0033822200031362.

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Abstract (sommario):

The 14C Quality Assurance Programme coordinated by the IAEA (Rozanski et al. 1992) prepared a set of five new intercomparison materials, including 40–50 ka old subfossil wood excavated from New Zealand peat bogs (IAEA C-4 standard). Statistical analysis of 79 14C measurements made on the wood indicated considerable variation in the results, with a marked skewness toward more modern values. The wide range of results and the possibility of inhomogeneity within the standard prompted the recovery and analysis of replacement material. The new subfossil wood sample is kauri (Agathis australis), at least 50 ka old, excavated from a swamp in Northland. It is in the form of a single plank, 6 m long, weighing 80 kg. It will be forwarded to the IAEA in Vienna for milling and distribution. Subsamples were obtained from both ends of the plank and analyzed by six laboratories. We present here the results of these analyses and compare them with the previous IAEA intercalibration results for the C-4 standard.

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44

Shahinfar, S., e L. Kahn. "Machine learning approaches for early prediction of adult wool growth and quality in Australian Merino sheep". Computers and Electronics in Agriculture 148 (maggio 2018): 72–81. http://dx.doi.org/10.1016/j.compag.2018.03.001.

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45

Pahl, L. I. "Adoption of environmental assurance in pastoral industry supply chains - market failure and beyond". Australian Journal of Experimental Agriculture 47, n. 3 (2007): 233. http://dx.doi.org/10.1071/ea06031.

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Abstract (sommario):

This paper describes adoption rates of environmental assurance within meat and wool supply chains, and discusses this in terms of market interest and demand for certified ‘environmentally friendly’ products, based on phone surveys and personal interviews with pastoral producers, meat and wool processors, wholesalers and retailers, and domestic consumers. Members of meat and wool supply chains, particularly pastoral producers, are both aware of and interested in implementing various forms of environmental assurance, but significant costs combined with few private benefits have resulted in low adoption rates. The main reason for the lack of benefits is that the end user (the consumer) does not value environmental assurance and is not willing to pay for it. For this reason, global food and fibre supply chains, which compete to supply consumers with safe and quality food at the lowest price, resist public pressure to implement environmental assurance. This market failure is further exacerbated by highly variable environmental and social production standards required of primary producers in different countries, and the disparate levels of government support provided to them. Given that it is the Australian general public and not markets that demand environmental benefits from agriculture, the Australian government has a mandate to use public funds to counter this market failure. A national farm environmental policy should utilise a range of financial incentives to reward farmers for delivering general public good environmental outcomes, with these specified and verified through a national environmental assurance scheme.

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46

Mizikovsky, I. E., e D. V. Lidzhi-Goryaev. "THE CONCEPT OF AN ELECTRONIC TRADING PLATFORM FOR MANAGING THE SUSTAINABLE DEVELOPMENT OF WOOL PROCESSING". Intelligence. Innovations. Investment, n. 6 (2020): 61–68. http://dx.doi.org/10.25198/2077-7175-2020-6-61.

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Abstract (sommario):

The relevance of the research is that in Russia there is a problem of underdevelopment of the system of purchasing wool and its processed products at all levels of the value chain. The purpose of the research is to develop a concept for creating a specialized electronic trading platform that allows organizing inter-industry interaction in the field of wool processing based on the principles of auction trade, excluding unnecessary intermediary links. The paper proposes the creation of a specialized electronic trading platform (exchange), specializing in the purchase and sale of wool and its products by analogy with the world’s leading (Australian, New Zealand and Chinese-countries that are world leaders in the production and processing of wool) wool exchanges. The differences between the author’s recommendations and those that are known and tested in the world practice are that the key participant of the exchange is the state national wool certification body, which creates the main condition for exchange trading — high-quality classification and batch standardization of wool. An electronic exchange that includes trading, settlement (guarantee) and payment systems must be an official trading platform licensed by the state as a professional Institute of the financial market; its main task is to facilitate market transactions between buyers and sellers of wool by overcoming information asymmetry for the parties to transactions. The difference between the proposed concept is that digital technologies and tools are used in exchange trading of wool: QR-coding of wool batches, the use of smart contracts, distributed registries (blockchain). The novelty of the research lies in the fact that for the first time in the Russian market, the concept of organizing electronic exchange trade in wool using innovative digital technologies and tools (QR-coding, smart contracts, blockchain), where, along with buyers-processors of wool and sellers — producers of wool, there is a mandatory participant — the state national certification body, which organizes the certification process of exchange batches of wool. In practical terms, the author’s proposals allow us to: streamline the domestic wool market; organize certified wool trade both in accordance with the best world practices and in accordance with m

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47

Clark, Judy. "The global wood market, prices and plantation investment: an examination drawing on the Australian experience". Environmental Conservation 28, n. 1 (marzo 2001): 53–64. http://dx.doi.org/10.1017/s0376892901000054.

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Abstract (sommario):

A global wood shortage generating real inflation-adjusted price increases for wood has been a long and widely-held expectation. This paper assesses the validity of this view by examining global trends in wood and wood-products consumption, developing a model to explain movements in wood prices and testing it empirically. No evidence was found of increasing real prices for wood over the long-term, indicating that there is no looming global wood shortage. A global wood shortage is not predicted because technology is increasing resource productivity, enabling wood products to be made using less wood, and also increasing wood supply. It is superficial to interpret this to mean that there is little to worry about from a native forest biodiversity perspective. The analysis presented in this paper suggests that real prices for wood are likely to continue to fall. This will discourage commercially-driven investment in plantation establishment on existing agricultural land. But industrial pressure will continue for a wood resource that is attractive in cost and quality terms, increasing the risk of biodiversity loss through intensification of native forest management and clearing of native forests for plantations. It is prudent to consider approaches that encourage plantation investment on existing agriculture land using the price mechanism. Currently, much private sector plantation investment is based on price expectations derived from an incorrect view of an imminent global wood shortage. Withdrawing old-growth forests from commodity wood supply is likely to increase wood prices in line with widely-held, though apparently false, expectations and also deliver an absolute best ecological outcome. As increasing volumes of wood become available from maturing plantations, government policy changes will be required to ensure that levels of logging in native forests actually decline rather than new markets being found for native forest wood. Despite its strategic commercial importance, little is known about the potential of the existing global plantation estate to supply wood. Addressing this information gap is a timely task that would enhance industry policy and clarify future plantation investment requirements.

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48

Mulholland, JG, e GK Preston. "A comparison of buckwheat, oats, and wheat for the maintenance of liveweight and wool production in sheep". Australian Journal of Experimental Agriculture 35, n. 3 (1995): 339. http://dx.doi.org/10.1071/ea9950339.

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Abstract (sommario):

Merino wethers about 2 years old were confined in pens and fed, daily or weekly, maintenance rations of whole buckwheat, crushed buckwheat, whole wheat, or oats. All rations were supplemented with a small portion of pasture hay and minerals and were compared for acceptance, digestible energy (DE), and wool growth. The DE of the ration containing whole buckwheat was 13.1 MJ/kg DM and was 86.3% of the DE value of the wheat ration and 11% higher than that of oats, but the oats were below average Australian quality. Processing buckwheat increased faecal energy loss and reduced DE by 8%. During the first 10 days of feeding, the sheep fed weekly lost 75 day compared with a gain of 6 g/day for the daily-fed group, but thereafter liveweights remained fairly constant. This resulted in an overall difference (P<0.05) between weekly and daily feeding. Significantly (P<0.05) higher food refusals were obtained with weekly feeding, but there was no difference between grain types. Wool growth was similar for all grains and for daily and weekly feeding. It was concluded that buckwheat is a suitable grain for maintaining liveweight and wool production of sheep.

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49

Alcorn, Philip J., Jürgen Bauhus, R. Geoff B. Smith, Dane Thomas, Ryde James e Adrienne Nicotra. "Growth response following green crown pruning in plantation-grown Eucalyptus pilularis and Eucalyptus cloeziana". Canadian Journal of Forest Research 38, n. 4 (aprile 2008): 770–81. http://dx.doi.org/10.1139/x07-185.

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Abstract (sommario):

Pruning of live branches is performed to enhance wood quality in plantation trees. Stem, branch and wood properties may be altered following pruning from below, but the extent and duration of such effects are unknown for many plantation Eucalyptus species. The effect of 0%, 20%, 50%, and 70% green crown length removal on growth and wood quality was examined in 3.5-year-old plantation-grown Eucalyptus pilularis Sm. (blackbutt) and Eucalyptus cloeziana F. Muell. (Gympie messmate) trees on two subtropical sites in eastern Australia. Growth increment of the stem at breast height was not affected by 20% crown removal. However, stem increment at breast height was reduced for up to 8 months with 50% crown removal and up to 12 months with 70% crown removal. Pruning had no impact on height growth. However, the height of trees pruned to 70%, relative to the height of the surrounding unpruned trees, was temporarily reduced 12 months after pruning in both species. Stem form, stem taper, wood density, and residual branch growth above the pruned zone were unaffected by pruning. Owing to the fast vertical crown expansion, trees were able to rapidly compensate for leaf area removal without long-term reductions in stem growth. The implications for management operations utilizing pruning as a means of enhancing timber quality are discussed.

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50

Downes, Geoffrey M., Jonathan J. Harrington, David M. Drew, Marco Lausberg, Phillip Muyambo, Duncan Watt e David J. Lee. "A Comparison of Radial Wood Property Variation on Pinus radiata between an IML PD-400 ‘Resi’ Instrument and Increment Cores Analysed by SilviScan". Forests 13, n. 5 (12 maggio 2022): 751. http://dx.doi.org/10.3390/f13050751.

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Abstract (sommario):

Mature age Pinus radiata D. Don trees were sampled across nine sites in northern New South Wales, Australia, that were expected, based on site quality and inventory metrics, to exhibit significant variation in productivity and wood quality. Twenty trees per site were harvested and 13 mm diameter, pith-to-bark increment cores were extracted from three trees per site from eight of the nine sites for SilviScan analysis. Outerwood increment cores were collected from all trees for basic density measurement. The same trees were also sampled using an IML PD400 (Resi) instrument. Radial mean properties of wood basic density derived from Resi traces were found to correlate strongly with the mean density data derived from SilviScan analyses and from increment cores. The Resi-derived basic density of 10 mm radial segments was strongly correlated with SilviScan measures of basic density averaged at similar intervals.

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