• Nutrition During Fetal Life Alters Annual Wool Production and Quality in Young Merino Sheep

    The effect of maintenance v, submaintenance diets of pregnant ewes in 1991 and 1992 on establishment of the wool follicle population in their progeny, and its effect on the progeny's wool production (quantity, quality and variation across the body of the animal) to 1.4 years of age was examined. The experimental protocol used cloned animals created by bisecting embryos at day 6 of pregnancy. Each clone was placed in a ewe, which was subsequently fed from about day 50 to 140 of pregnancy at maintenance or submaintenance. Ewes on maintenance nutrition maintained liveweight throughout pregnancy, while submaintenance ewes were 12.1 kg lighter (P < 0.001) 10 days before lambing. In 1991, a total of 74 lambs were born, including 17 sets of surviving clones. In 1992, 102 lambs were born, including 18 sets of surviving clones. Only data for the 35 sets of genetically identical 'twin' progeny and their dams are reported. Birth weights of lambs born to ewes fed at the submaintenance rate were 0.5 kg lighter (P < 0.01) than their 'twins' born to ewes fed at maintenance. Midside secondary:primary (Sf: Pf) ratios for mature wool follicles were less (P < 0.01) at birth, lamb and hogget shearing (1.4, 1.5 and 2.1 units respectively) for the progeny born to ewes fed at submaintenance. Progeny from ewes on the submaintenance treatment produced less clean wool, 0.1 kg to 0.4 years of age (P < 0.01) and 0.14 kg between 0.4 and 1.4 years of age (P = 0.10), than their maintenance counterparts. Hogget wool was 0.1 pm broader (P < 0.05), with a 0.5% units lower coefficient of variation of fibre diameter (P < 0.01), and a position of break closer to the staple tip (P < 0.001) for progeny of submaintenance ewes than their maintenance counterparts. There were no significant differences in yield, staple length, staple strength and percentage of fibres greater than 30 pm in diameter. Differences in mean fibre diameter arose between 1 and 1.4 years of age, coinciding with the period that the animals were grazing high quality pasture. Effects of maternal undernutrition on mean fibre diameter and Sf: Pf follicle ratios of progeny were most pronounced on the hind leg (P < 0.01), and not significant on the front leg. However, variations in other wool quality traits across the body of the hoggets, expressed as a percentage of the midside value, were not significantly affected by maternal undernutrition. Clearly when evaluating management strategies for the pregnant ewe, the effect on lifetime production and quality of wool of their progeny needs to be considered. Merino hoggets that produce an extra 0.14 kg clean wool that is 0.1 pm finer will compensate for some extra management and feeding of their dams during pregnancy to prevent weight loss. If these effects continue throughout the life of the animal, then it will increase the cost effectiveness of feeding to maintain maternal weight over pregnancy. more »
  • The Effects of Pasture Inputs and Intensive Rotational Grazing on Superfine Wool Production, Quality and Income

    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. more »
  • Production, Attributes and Relative Value of Alpaca Fleeces in Southern Australia and Implications for Industry Development

    An investigation of commercially important alpaca fibre attributes aimed to identify the influence of management and production variables on alpaca fibre and to quantify the relative economic value of fibre production. Fleeces from five farms in southern Australia (n = 1100) were measured using midside samples and standard tests and were assigned a relative economic value based on an analysis of market price data. Greasy fleece (GFW) and saddle weights of Huacayas peaked at 2 years and Suris at 3 years of age and then declined with increases in age until 6 years of age. GFW of Huacaya were not affected by mean fibre diameter (MFD). In Suris, GFW increased with MFD reaching a peak at 29–33 μm. Mean ± S.D. of clean washing yield was 92.0 ± 1.5%. The proportion of the fleece as saddle, neck and skirting components was (mean ± S.E., %): saddle 55.9 ± 0.9, neck 16.3 ± 0.5, skirtings 27.8 ± 0.6. About, 10% of Huacayas had fleeces with MFD < 24.0 μm, while 14% of Suris had fleeces < 24.0 μm. Both Huacayas and Suris had about 50% of fleeces with mean fibre diameter > 29.9 μm. One-third of Huacaya and Suri saddles had 50% of their fibres medullated. For Huacaya and Suri alpaca, the incidence of medullated fibres increased linearly from 10 to 60% by weight as MFD increased from 20 to 36 μm. The ratio of medullated fibre diameter to MFD declined as MFD increased. For Huacaya, there was no change in average staple length as MFD increased. Huacaya alpaca had a greater fibre curvature than Suri alpaca. Data on resistance to compression and staple strength was correlated with other fibre attributes. The price declined by 11% per 1 μm increase in MFD from 22 to 26 μm and by 5% per 1 μm increase between 27 and 34 μm. The total relative economic value increased with increasing GFW and with increasing saddle weight up to 2.5 kg. Total relative economic value declined as MFD increased above 23 μm, increasing live weight above 60 kg and with increasing age above 2 years for Huacaya and 3 years for Suri. The productivity and economic returns from fleece production of Huacaya and Suri breeds was similar. The Australian industry needs to implement commercial mating, shearing and culling strategies to maximise production and returns from animals aged less than 3 years. The main driver of economic value from fleece production was lower MFD of the fleece. more »

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