Seasonal Variation in Hair Follicle Activity and Fiber Growth of Both Male and Female Merghoz Goats in Western Iran

In a study conducted over a year with 10 female and 10 male Merghoz goats in Western Iran, researchers found significant seasonal variations in hair follicle activity and fiber growth. The study measured follicular density, the percentage of active primary and secondary follicles, the ratio of secondary to primary follicles, clean fiber yield, and fiber diameter, with skin biopsies and fiber samples taken monthly. Results showed that primary and secondary follicle activity varied significantly with the seasons (p < 0.001), with the highest activity in summer and spring and the lowest in winter. However, no seasonal differences were observed in follicular density and the secondary to primary follicle ratio. Additionally, there was a significant interaction between season and sex on both fiber growth rate and fiber diameter. The study concluded that goats experience seasonal cycles in feed intake, growth, hair follicle activity, and fiber growth.