BACKGROUND: Using methionine in the diet of the small ruminants can induce the growth of follicles and their fibre growth. OBJECTIVES: In this study, the effect of oral coated methionine on the hair follicles was determined in female Rayeni goats and their breastfed kids during the first 2 months of infancy. METHODS: For this purpose, 60 healthy singleton born Rayeni goats, approximately 3 to 4 years of age with their one-day-old kids were randomly divided into 4 equal groups. The treated mothers group was given 3 gr/day pure oral methionine manually for 60 days. Skin samples of the 4 groups were taken from the middle of the left and right side, on zero, 30 and 60 days of experience. Routine histological processes were done. In each sample, primary and secondary follicles and skin follicles traits, the diameter of the primary and secondary follicles, the diameter of hair and cashmere, the diameter of dermal papilla of primary and secondary follicles and the number of primary and secondary follicles were measured respectively by linear graticule under light microscope. The diameter and percentages of the cashmere of mothers and kids, the firmness, and the length of the cashmere of kids were measured macroscopically. All data were analyzed with SPSS statistical software. RESULTS: The results showed that the oral coated methionine in the diet of the mothers could significantly increase the diameter of primary and secondary follicles and their dermal papilla. In the treated kids, the diameters of the primary and secondary follicles, the dermal papilla of the primary and secondary follicles and the number of secondary follicles showed significant change. CONCLUSIONS: According to the study, the oral coated methionine in the diet of the mothers during the first 2 months of infancy can significantly increase the diameter of primary and secondary follicles and their dermal papilla in the mothers and their treated kids. It can also increase the number of secondary follicles in the kids.