Cashmere production from feral and imported cashmere goat kids

Abstract

AbstractCashmere production was evaluated on Scottish feral (F) goats, on goats imported from Iceland (I), Tasmania (T), New Zealand (N) and Siberia (S), and on two- and three-way crosses between feral and imported lines. Evaluations were based on the weight of cashmere in 10 cm2 mid-side patch samples taken at 5 months of age, with annual cashmere production being predicted from sample cashmere and body weights. Data were collected on 121 purebred and 706 crossbred kids of both sexes. Mean fibre diameter for the F, I, T, N and S lines was 13-75 (s.e. = 0.82), 14·04 (s.e. 0·41), 16·13 (s.e. 0·35), 16·63 (s.e. 0·49) and 17·97 (s.e. 0·50) μm, mean estimated annual cashmere production was 37·3 (s.e. 71·3), 914 (s.e. 31·7), 227·1 (s.e. 28·1), 275·1 (s.e. 42·5) and 579·8 (s.e. 44·7) g, and mean live weight was 15·71 (s.e. 2·16), 17·65 (s.e. 0·93), 16·39 (s.e. 0·83), 16·53 (s.e. 1·28) and 21·9 (s.e. 1·28) kg, respectively. Significant positive heterosis existed between some lines for body weight and cashmere production, with the I line goats consistently showing the largest effects. Combining fibre diameter and cashmere production by their relative economic importance into an index designed to indicate the total value of the fibre produced by each genotype, the cashmere production index, reduced the large production differences between the lines, although the S line was still superior to all other lines. When the cashmere production index was adjusted to account for the economic importance of fibre colour, however, the T and N lines, the only lines which produced white fibre, were comparable to the S line. The cashmere production index for the S line was very sensitive to changes in the relative economic weight for fibre diameter, and if the price differential for high quality (i.e. fine) fibre was increased by a factor of 1·36, or greater, then the T and N lines were superior to the S line. Three-way cross means were estimated from line means and heterosis effects. No cross was consistently superior to all other genotypes, but several of the crosses showed the advantages of potentially producing white fibre as well as having high cashmere production indexes, with their indexes being insensitive to changes in the relative economic weights. Future selection for cashmere production in this population should concentrate on individuals of outstanding genetic merit, regardless of their line or cross.