In the current study, the effects of dietary supplementation of protein, probiotics and vitamins (C and E) on semen quality and immunohistochemistry of pituitary gland in zinc-induced molted male layer breeders were evaluated. For this purpose, male layer breeders (n=270) at the age of 59 weeks were used. After acclimatization of one week, all birds were subjected to forced molt by dietary supplementation of ZnO for a period of two weeks. After completion of molting, the birds were divided into six equal groups, keeping one group as control. The other groups were fed diet supplemented with protein (12%), probiotics (50 mg/kg feed), vitamin C (500 mg/kg feed), vitamin E (100 mg/kg feed) and combination of all above treatments, respectively. The birds took about 5 weeks to produce semen after molting. The trial continued for next 5 weeks during which semen and pituitary samples were collected from 5 and 3 birds of each group respectively, once a week. The results indicated that semen volume and sperm motility increased, while %age of dead sperm decreased, significantly in vitamin C and E treated groups. The results of immuno-histochemistry also showed that the size of FSH gonadotrophs, LH gonadotrophs and lactotrophs were significantly higher in vitamin E supplemented group which ultimately caused an increase in semen quality. Hence, the above results advocate the use of vitamin C and E in post molt male layer breeders to improve their reproductive performance.

Key words: Immunohistochemistry, Layer breeder, Molting, Pituitary gland, Probiotics, Semen quality, Vitamins