B. A. McGregor

Nutrition, management and other environmental influences on the quality and production of mohair and cashmere: A review with particular reference to mediterranean and annual temperate climatic zones

Goat fibre production is affected by genetic and environmental influences. Environmental influences which are the subject of this review include bio–geophysical factors (photoperiod, climate–herbage system and soil–plant trace nutrient composition), nutrition factors and management factors. Nutrition and management influences discussed include rate of stocking, supplementary feeding of energy and protein, liveweight change, parturition and management during shearing. While experimental data suggest affects of seasonal photoperiod on the growth of mohair and cashmere are large, these results may have confounded changes in temperature with photoperiod. The nutritional variation within and among years is the most important climatic factor influencing mohair and cashmere production and quality. Mohair quality and growth is affected significantly by rate of stocking and during periods of liveweight loss by supplementary feeding of either energy or protein. Strategic use of supplements, methods for rapid introduction of cereal grains, influence of dietary roughage on intake and the economics of supplementary feeding are discussed. Cashmere production of young, low producing goats does not appear to be affected by energy supplementation, but large responses to energy supplementation have been measured in more productive cashmere goat strains. The designs of these cashmere nutrition experiments are reviewed. Evidence for the hypothesis that energy-deprived cashmere goats divert nutrients preferentially to cashmere growth is reviewed. The influence and potential use of liveweight manipulation in affecting mohair and cashmere production and quality are described. Estimates of the energy requirements for the maintenance of fibre goats and the effect of pregnancy and lactation on mohair and cashmere growth are summarised. The effects and importance of management and hygiene during fibre harvesting (shearing) in producing quality fibre is emphasised. The review concludes that it is important to assess the results of scientific experiments for the total environmental content within which they were conducted. The review supports the view that scientific experiments should use control treatments appropriate to the environment under study as well as having controls relevant for other environments. In mediterranean and annual temperate environments, appropriate controls are liveweight loss and liveweight maintenance treatments. Mohair producers must graze goats at moderate rates of stocking to maximise animal welfare, but in so doing, they will produce heavier goats and coarser mohair. In mediterranean and annual temperate environments, seasonal changes in liveweight are large and influence both quality and production of mohair and cashmere. Mohair and cashmere producers can manipulate liveweight by supplementary feeding energy during dry seasons to minimise liveweight loss, but the economics of such feeding needs to be carefully examined. Strategic benefits can be obtained by enhancing the growth of young does prior to mating and for higher producing cashmere goats.

Effects of different nutritional regimens on the productivity of Australian cashmere goats and the partitioning of nutrients between cashmere and hair growth

The influence of energy or protein supplementation or energy restriction on cashmere growth was studied in 35 highly productive cashmere wether goats. The goats were shorn on 3 December and randomly allocated to 3 levels of energy intake: M, goats fed to maintain liveweight; 0.8M, goats fed to lose 5 kg liveweight from December to April and then fed ad libitum; and >M, goats fed to gain liveweight. Nested within >M were ADLIB (goats offered feed ad libitum), and 1.25M and l.5M (goats fed M plus 25 or 50% of the difference in mean intake between M and ADLIB). The metabolisable energy requirement to maintain liveweight was 250 kJ kg-0.75 day-1 but to maintain body condition (l.25M) it was 3 12 kJ kg-0.75 day-1. Goats fed 0.8M had a mean intake of 0.68M and lost 26 g day-1 liveweight until April, but when fed ad libitum consumed 2.15M in June and grew rapidly in late autumn and winter at 93 g day-1. Goats fed ADLIB consumed 2.30M in February and gained 87 g day-1 from December to February, but intake declined to 1.61 M in June and they gained 20 g day-1 from April to June. Cashmere growth and fibre diameters of fleeces shorn on 17 June of goats fed >M (221g, 17.69 pm) were significantly greater (P M, there were no significant differences in cashmere growth. Protein supplementation within M (27 or 54 g day -1 formaldehyde- treated casein) resulted in 40% more wool growth in sheep (P<0.001), but no increase in cashmere or hair growth in goats. Goats fed ADLIB had significantly reduced cashmere yields (P < 0.05) and grew more hair (P<0.05) than did goats in other treatments. About 4 weeks after energy supplementation, fibre diameter of previously energy-deprived goats increased (P< 0.01). Midside patches indicated that energy-deprived goats, which lost liveweight, diverted nutrients preferentially to cashmere growth, while goats fed ADLIB partitioned nutrients towards hair growth. To maximise cashmere growth, supplementary energy should be supplied to avoid liveweight loss from December to April. Goats that had small (1-2 kg) liveweight gains and maintained body condition achieved near maximal levels of cashmere growth.

Influence of nutrition, fibre diameter and fibre length on the fibre curvature of cashmere

Raw and dehaired Australian and Chinese Liaoning cashmere were evaluated for cashmere fibre curvature, cashmere fibre length, resistance to compression, and mean fibre diameter. Tested cashmere originated from commercial lots, and previous experimental samples. In Australian goats, cashmere fibre curvature was dependent on nutrition. Goats fed to lose weight grew cashmere with significantly (P<0.05) increased fibre curvature compared with goats fed to gain weight (61 v. 47°/mm) but total fibre curvature (fibre curvature × fibre length) was not affected by nutrition treatment. In raw Liaoning cashmere, there was a significant (P<0.001) difference between each age and sex group in fibre curvature (bucks 52; does 65; kid bucks 78°/mm). Increasing Liaoning cashmere staple crimp frequency by 1/cm was correlated with an increase in fibre curvature of 6.5°/mm (r2 = 0.61). In raw and dehaired Australian and Liaoning cashmere, increasing mean fibre diameter and cashmere fibre length was associated with decreasing fibre curvature (for each 3 μm increase in mean fibre diameter fibre curvature declined 10–41°/mm; for each 10 mm increase in cashmere fibre length fibre curvature declined 3–13°/mm). Increasing cashmere mean fibre diameter was positively correlated with dehaired cashmere fibre length (for each 3 μm change in mean fibre diameter there was a change of 7–23 mm in length). In Australian and Liaoning cashmere, the direction of responses to changes in cashmere fibre attributes measured on the fibre curvature was similar. In raw Australian and Liaoning cashmere, increasing the ratio of cashmere fibre length:mean fibre diameter was associated with reduced fibre curvature. It was concluded that the high fibre curvature of Liaoning cashmere may be a consequence of low mean fibre diameter and short fibre length resulting from a production system where goats are relatively poorly fed. The results suggest that for Australian cashmere, only a certain number of crimps are produced. As such, crimp frequency in Australian cashmere is time dependent and not length dependent. Producers can manipulate the fibre curvature attributes of their cashmere by altering cashmere production via nutrition management. Preparation and testing procedures for the selling of raw cashmere and definitions of cashmere may need to be revised to include fibre curvature.

Contribution of objective and subjective attributes to the variation in commercial value of Australian mohair: implications for mohair production, genetic improvement, and mohair marketing

A database collected in the years 1998–01, from 2 mohair-selling agents in Australia, was analysed using multiple regression analysis to determine the effect on commercial sale prices of year, selling season within year, agent, mean fibre diameter (MFD), coefficient of variation of fibre diameter [CV(D)], vegetable matter base (VM), Schlumberger dry yield, visually assessed staple length, visually assessed fibre style, incidence of kemp, other faults, and interactions of these effects. The database consisted of 557 objectively measured lots. The weighted means ± s.d. of attributes analysed were: MFD, 30.9 ± 3.7 μm; CV(D), 29.1 ± 2.6%; VM, 1.0 ± 1.0%; Schlumberger dry yield, 84.0 ± 2.7%; lot weight, 1186 ± 938 kg. The final model for the price of greasy mohair had fixed terms involving a combination of selling agent, selling period, MFD, VM, and visual classing grades. This model accounted for 98% of the variation of the logarithm of greasy mohair price. Agent and selling period combinations accounted for 22% of the variation. Terms involving MFD accounted for 59% of the variation not accounted for by agent and period combinations. Although the response of greasy mohair price to MFD differed greatly with period, in the second quarter of 1999 the maximum relative price of greasy mohair was reached at a MFD of about 25 μm. The relative price typically declined to about 50% of the maximum at 30 μm and to a price of 10% of the maximum at 36 μm. The increase in relative value from poor to superior style mohair was about 43%. There were large discounts for length (up to 48%), kemp (up to 87%), and light stained mohair (70%). Deviations due to length differ with time and MFD. The discount for fault lines was proportionally higher when MFD was low, and proportionally less serious when the mohair MFD was high. The discount was proportionally greater the more serious the fault. There was a curvilinear response to the presence of VM in mohair and an interaction of VM with MFD, but these terms only accounted for the last 0.5% of the variation. After allowing for the effects of selling, agent, visual attributes, MFD, and VM, neither Schlumberger dry yield nor CV(D) was related to greasy mohair price. CV(D) was related to length, kemp, fault, and MFD. Apart from the current practice of price reporting on a greasy basis, the information supplied by agents provides transparency in mohair transactions as the current objective measurements and visual appraisal explain 97% of the variation not explained by agent and period of sale.

Complementary selection and intake of annual pastures by sheep and goats

Abstract The compositions of diets of Merino sheep and Angora goats were determined when they grazed annual pastures (Wimmerarye Lolium rigidum; Barley grass, Hordeum leporinum; Silver grass, Vulpia bromoides; Subterranean clover, Trifolium subterraneum) in March, May, August and October, 1985 and in February and April, 1987. Oesophageally-fistulated sheep and goats were stocked at 7.5 and 10/ha on pastures with 1.7–2.9 t available DM/ha in 1985, 3.0–4.5 t/ha in 1987. On all occasions, both species selected a diet with more green herbage, N and digestible organic matter than on offer in the pasture. Except in February, sheep selected a diet with more green clover, less green grass and dry herbage, higher in N (3.3–3.9% vs. 2.8–3.4%) and lower in ADF (24–39% vs. 27–44%), than did goats; differences were significant except in February and March when 98% and 93% of available pastures were dry herbage. In vitro OM digestibilities, about 40% in February and at least 68% in March, April, August and October, did not differ between sheep and goats. In May, goats selected a diet of 66% dead herbage vs. 20% for sheep, 44% ADF vs. 29%, 1.7% N vs. 3.3% and in vitro digestibility was 12% lower (P

The Effects of Cashmere Attributes on the Efficiency of Dehairing and Dehaired Cashmere Length

This study investigated the effects of raw cashmere attributes on the efficiency of dehairing and on dehaired cashmere length. The results show that the following attributes of raw cashmere were associated with more efficient processing and/or the production of longer cashmere: white color; longer raw cashmere; greater fiber curvature; lower vegetable matter; normal length guard hair; absence of visible cotting. Raw cashmere with a higher cashmere content and higher fiber diameter processed less efficiently than raw cashmere with a lower cashmere content and finer fiber diameter. This work identifies the value of using raw cashmere staple length and cashmere fiber curvature measurements, and shows that the variation explained by known attributes on cashmere processing efficiency was high. These results are applicable to cashmere classing, breeding, processing, and the value of the final product.

A NOTE ON THE ASSESSMENT OF DOWN PRODUCTION IN AUSTRALIAN 'CASHMERE' GOATS

Down production of 93 feral, F, and F2 cashmere-producing goats run in Victoria was investigated. The goats were visually assessed for down production and shorn. Their fleeces were evaluated for total fibre, down yield, fibre diameter, grease and moisture content. Analyses on down yield and fleece characteristics indicated that they compared favourably with those of traditional cashmere-producing countries. Mean down production ranged from 330 g for males to 148 g for females. Sampling at three body sites was accurate in determining total fleece measures and visual assessment proved a reliable screening technique for on-farm selection. Large variation was found in down production indicating the possibility of rapid genetic gain through selection.

Mechanical properties of cashmere single jersey knitted fabrics blended with high and low crimp superfine merino wool

In this replicated experiment, we investigated the impact of cashmere in blends with superfine wools on the mechanical properties of single jersey knitted fabrics. We also investigated the relative performance of soft, low crimp/low fiber curvature superfine wool when compared with cashmere and also when compared with traditional high crimp/high fiber curvature superfine wool in pure and blended knitted fabrics. The results indicate both the cashmere blend ratio and fiber curvature/crimp of wool affected fabric properties. Pure cashmere fabrics were softer than pure wool fabrics. Adding cashmere to wool increased knitted fabric softness, smoothness, flexibility, and suppleness. The physical properties of pure low crimp wool fabrics were closer to the properties of pure cashmere fabrics than were knitted fabrics made from pure standard wool.

Influence of stocking rate and mixed grazing of Angora goats and Merino sheep on animal and pasture production in southern Australia. 2. Liveweight, body condition score, carcass yield and mortality

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 the liveweight, body condition score, carcass yield and mortality of goats and sheep were determined in a replicated experiment on improved annual temperate pastures in southern Australia from 1981 to 1984. The pattern of liveweight change was similar for both species with growth from pasture germination in autumn until maturation in late spring followed by weight loss. In winter, sheep grew faster than goats (65 versus 10 g/day, P 0.8). Both AS and SR affected (P < 0.001) carcass weight and GR tissue depth as a direct result of differences in liveweight. Adjusting for differences in carcass weight negated AS effects on GR tissue depth. The carcass weights of sheep and goats increased by similar amounts for each 1-kg increase in liveweight. Mortality of sheep (3.1% p.a.) was unaffected by AS or SR. An AS × SR interaction indicated mortality of separately grazed goats at 12.5/ha and mixed-grazed goats at 10 and 12.5/ha were higher (P < 0.05) than all other goat (29 versus 9%) and sheep treatments, primarily because of increased susceptibility to cold stress. Disease prevalence differed between sheep and goats. Mixed grazing of Merino sheep and Angora goats produced complementary and competitive effects depending upon the SR. Goats used summer pasture better but winter pasture less well for liveweight gain than sheep. 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 and the evidence indicates a lower SR will reduce risks associated with mortality.

Optimising sampling techniques and estimating sampling variance of fleece quality attributes in alpacas

Huacaya and Suri alpacas (n ¼ 120) of varying age, live weight (LWT) and sex (female, male) were selected randomly from four farms in southern Australia. At shearing, fleeces were divided into four components: saddle (S), neck (N), pieces (P; front and back legs, belly, apron) and the midside sample (MS). Components were weighed, sampled using the grid sampling technique and fleece attributes measured: clean washing yield (CWY), mean fibre diameter (MFD), coefficient of variation of the MFD (CV(D)), incidence of medullated fibres (Med), mean medullated fibre diameter (MedMFD) and coefficient of variation of the MedMFD (MedCV(D)). The MS and saddle grid sample (SGS) were used to create models to predict the fleece attribute of the total fleece (TF), saddle and neck fibre. For each fleece attribute MS had lower values than SGS and TF (P < 0:005) and SGS, except for CWY, had lower values than the P and TF (P < 0:005). The means were: MFD MS 27.5 mm, S 28.8 mm, N 28.7 mm, P 37.6 mm, TF 31.2 mm; CV(D) MS 24.3%, S 27.0%, N 28.6%, P 30.6%, TF 28.1%; CWY MS 90.2%, S 91.4%, N 88.9%, P 92.8%; Med 24.4%, S 33.1%, P 44.5%, TF 35.2%; MedMFD MS 32.7 mm, S 34.4 mm, P 41.1 mm, TF 36.0 mm; MedCV(D) MS 19.4%, S 22.3%, P 25.9%, TF 23.4%. The MS was found to be an appropriate sample from which to predict the MFD and CWY. CV(D) was only satisfactorily predicted by the SGS (r ¼ 0:88), with the exception of the neck fleece, for which neither the MS nor SGS could provide an accurate predictive model. The MS did not sufficiently account for the variation in Med (r ¼ 0:73‐0.79). The SGS gave accurate prediction of Med (r ¼ 0:98). Sex effects were detected in models for TFMFD, NMFD and TFCV(D). LWT effects were detected in models for NMFD, NCV(D) and TFMedMFD. SGS often gave a more accurate prediction of a fleece attribute but it requires the removal of the entire fleece, whereas MS can be removed by shearing a small area or can be removed during shearing with a minimum of effort. Sampling variance for SGS was generally two to four times greater than the sampling variance for MS with the 95% confidence limits (CLs) for SGS being about double those of MS for most parameters except for clean washing yield (CWY) which were similar. Sampling variance for the incidence of medullated fibres in SGS was very high. The large 95% CL for all the tested fibre attributes indicate that alpaca breeders and advisors need to consider taking suitable duplicate measurements and other precautions during breeding and animal selling programs. Crown Copyright # 2002 Published by Elsevier Science B.V. All rights reserved.