Cashmere typically grows from mid-summer, when cashmere fiber growing follicles become active, until late autumn or early winter when follicle activity declines. Unlike Merino sheep or Angora goats which have continuously growing commercial fibers, cashmere goats grow their commercial fleece in only half a year. It is important for producers to be made aware of environmental factors which may affect cashmere growth during the limited period of its growth. As nutritional variation both within and between years is the most important environmental factor influencing wool growth (Black and Reis 1979) a series of experiments has been undertaken in Australia to assess the influence of nutrition on cashmere production.
General industry advice and practices of goat farmers are to provide adequate levels of nutrition to young, weaned goats to prevent liveweight loss following weaning. However, in terms of the likely effect of nutrition on cashmere production, research. suggests that nutrition has little or no effect on the production of cashmere from weaner goats.
In the study by Ash and Norton (1987) weaner cashmere kids were grazed on fertilized grass pastures. The weaners were fed various protein supplements. The experiment began in the fall when the weaners were 5 months of age and had a mean liveweight of 13.7kg (30.14 lb). At this age, the weaners had fleeces with 6 g of cashmere. After 98 days of grazing and supplementation, the cashmere harvested from the entire fleeces from one shearing was equivalent to total production of the Control group which had no supplementation, some 24 g of cashmere. Fed protected or unprotected protein, they produced 30 g of cashmere. This difference is not statistically significant. During this study, weaners grew rapidly during the first 24 days, maintained weight in the second 24 days and lost 25 g/day during the last 48 days.
This experiment confirmed earlier research by Ash and Norton (1984) in which weaned kids (initial liveweight, 13.6 kg) were fed a range of energy and protein levels. The authors observed increased body growth rates over a 70 day period when protein or energy content of the diet was increased. No improvements in midside patch fleece growth was observed. Johnson and Rowe (1984) studied the effect of protein nutrition on the cashmere growth of wether weaners fed for 126 days during the fall. They obtained significant increases (from 79 to 114 g/d) in body growth rate as protein intake increased. There were no statistically significant differences in cashmere production. Mean cashmere production from Control group shorn fleeces was 53g, and from the supplemented group, 61g.
In these three studies, nutrition only affected hair growth in one study and then by only 10 g (Ash and Norton 1987). While improved nutrition does not appear to have economic responses in terms of cashmere production, there are other important economic effects of improved nutrition of weaner kids. These include improved commercial value of kid carcasses and alteration of the reproductive potential of weaners.
The commercial value of kid carcasses was substantially increased by improved nutritional management provided by MacGregor et al (1988) instead of slaughtering kids at weaning. In this study, weaned kids weighed 13.3 kg (29.26 lbs) and produced carcasses of 5.3 kg (11.66 lbs) with 0.2 mm of subcutaneous backfat (sbf) – these carcasses being of little commercial value. After feeding hay and 400 g/d of lupine and barley for 98 days, buck and wether kids produced 9.7 kg 21.34 lbs) of carcass with 1.2 mm sbf and doe kids produced 7.8 kg (17.16 lb) carcasses with 1.0 mm sbf. These products were a very attractive commercial product, regarded as ideal for the Eastern ethnic market.
Supplementary feeding of weaner cashmere kids can also increase the number reaching puberty. Kids were fed supplements of barley, lupine and hay from weaning in the summer. Controlled does grazed dry summer pasture. Supplementation resulted in live weight gains of 4 kg above grazing. which lifted some doe weaners above the weight threshold for puberty (approx. 15 kg) and resulted in the onset of oestrus earlier in autumn. While earlier mating may be an advantage in some enterprises, most producers want to avoid early mating of doe kids. To avoid accidental matings, these authors recommend separating weaned bucks from all females.
Improving nutrition of weaner goats above current industry practices is unlikely to improve cashmere production. Improved nutrition will result in increased liveweight of weaners. more commercially attractive carcasses, will affect onset of puberty and require changes in management. The effects of variation in energy intake on total cashmere growth were large with a 51 percent increase in cashmere production when energy supply increased from below maintenance (0.8M) to above maintenance (1.25M). These observations support the hypothesis that energy restrictions during the period of cashmere growth reduce cashmere production.
In this experiment there was no difference in cashmere production between the above maintenance level (1.25M) treatments and so the lowest level of feeding 0.8M is recommended (M being the level of food intake required to maintain body weight). Goats fed at 1.25M gained 1-2 kg liveweight from December to April and maintained body condition score throughout the experiment. Cashmere goat farmers can therefore use body condition scores to ensure that cashmere goats maintain body condition and achieve near maximal levels of cashmere production during summer [in the northern hemisphere, winter].
Increased cashmere production of goats fed M compared to goats fed 0.8M was associated with a 1 micron increase in cashmere fiber diameter which represented a 13 percent increase in cross sectional area and accounted for 25 percent of the increase in total cashmere growth. Whether energy supplementation to increase cashmere growth is economic depends not only on the increase in cashmere growth but also on the cashmere price discount due to increased fiber diameter. [Currently, there is no price discount for increased fiber diameters]. It is clear from this experiment that both total energy intake and pattern of energy intake affect cashmere growth. By coincidence, at the conclusion of the experiment, the total energy intakes of goats fed 0.8M and M were similar. However, the different patterns of energy intake resulted in different growth patterns and characteristics of cashmere. (Goats fed 0.8M lost weight for 4.5 months and then were fed ad libitum). The decision about whether it is economical to supplement feed cashmere goats over a summer depends on many issues. A brief discussion of these issues and some examples are provided:
COMMENTS – In this program, gross returns increased 30 percent (with 500 goats equal to about $2100 AUD. $1500 USD). Before supplementary feeding programs are undertaken, it is essential that producers assess carefully which parts, if any, of their flocks should be fed. Goat owners in subtropical, high rainfall and pastoral zones [such as south Texas or perhaps western Oregon or Washington] will have to carefully assess if any potential exists to improve cashmere production prior to undertaking feeding. In wheat\sheep environmental zones, it is unlikely that economic responses will be obtained to extra feeding during seasons with high summer rainfall resulting in green pastures.
CONCLUSIONS – The results clearly indicate that to maximize cashmere growth of goats grazed in wheat-sheep environments of Australia, supplementary energy should be supplied to avoid normal seasonal liveweight loss from December until April. Goats which have small liveweight gains (1-2 kg) and can maintain body condition over the summer [winter] will achieve near maximal levels of cashmere production. Energy nutrition influences cashmere fiber diameter and total cashmere production over the entire growing season.
Editor's Note: Seasonal differences between Australia and the US are minimized because it is the summer in Australia that results in liveweight losses while it is the winter in the US that does so. Another factor is that here, does will be pregnant during winter, requiring greater energy intake needs than does in Australia, which are normally pregnant in April-Sep. Feed enough during the winter to maintain body weight or gain 1-2 kg. Feeding more will only increase your fiber diameter and decrease your total cashmere.