Effect of nutrition on lipid production and composition of Cashmere buck fleece

Abstract

This study examined the lipid content and fatty acid composition of fleece samples collected in April, which is during the breeding period, from different body regions of Cashmere bucks fed ad libitum diets of high (pelleted lucerne, Medicago sativa, 8.3 mJ kg −1 ME, 17.6% CP) and low (coarsely hammermilled pangola grass, Digitaria decumbens, 6.6 mJ kg −1 ME, 6.9% CP) quality. For both groups of bucks the ethyl-branched fatty acid concentrations were significantly greater from the neck region compared with the mid-side or hind regions. Also, for the fleece samples collected in April, bucks fed the high quality diet (lucerne) produced greater amounts of lipid and ethyl-branched fatty acids in their fleece than the bucks fed the low quality diet (pangola grass). These increases occurred for neck, mid-side and hind regions. The lipid content and ethyl-branched fatty acid concentrations of fleece samples from the neck regions of bucks on high and low quality diets were also examined at various times of the year and showed seasonal variation. Both increased earlier in the year for the bucks fed lucerne than for those fed pangola grass. It would appear that the odour (pheromone) of the buck is related to fleece lipid production. Therefore, good nutrition may be a way of maximising the pheromone levels in the buck and consequently the buck effect which initiates ovulation in does.