Hormonal control of grooming behavior in domestic goats

In this study, further documentation of the modulation of self-grooming by testosterone was provided by an experiment which showed that self oral grooming in long-term castrated male goats of the dwarf Shiba breed was significantly down-regulated to one-third of the baseline grooming rate by testosterone supplementation. Observations on grooming in gonadally intact female Shiba goats in the summer (July) and in the fall (October) showed that the oral grooming rate was significantly higher in the fall, occurring at about twice the rate in the summer. The female oral grooming rate in the fall was the same as the baseline rate of castrated males before testosterone supplementation. The seasonal increase in females was not attributed to changes in gonadal hormones. The adaptive significance of hormonal regulation of the timing mechanism for grooming in both male and female goats, and possibly other ungulates, is discussed.