The Endocrine control of fibre growth and shedding in cashmere goats

Extract

The coat of the cashmere goat consists of two types of fibre, a coarse outer coat of guard hair produced by the primary skin follicles and a fine undercoat of cashmere (˂18.5 microns diameter) produced by the secondary follicles. In the spring both the primary and secondary follicles shed their fibres and a sparse coat of mainly guard hair is maintained over the summer. Many temperate mammalian species display photoperiodically regulated changes in the pelage which alter the insulating properties of the coat and prepare the animal for large variations in ambient temperature. The timing of the moult can be manipulated by changes in photoperiod (Allain et al, 1986) or treatment with melatonin or prolactin. Smith et al (1987) demonstrated that melatonin treatment from August in the male Blue-fox prevented both the onset of the moult and the spring rise in prolactin. In the Djungarian hamster prolactin treatment induced the spring moult and the suppression of prolactin by bromoergocriptine inhibited the moult (Duncan and Goldman, 1984).