Abstract
It is well documented that aging has negative effects on fertility. With increasing age, the activity of antioxidant enzymes are reduced and because of roosters sperm composition, a high proportion of polyunsaturated fatty acids (PUFAs), the probability of sperm damage increases. The objective of the present study was to compare the effects of nano-selenium and sodium selenite on fertility in aged male broiler breeder chickens. Thirty-five male broiler breeders (Cobb 500)(®) at 50 weeks of age were randomly divided into five equal groups: The control group was fed on a commercial diet, group T1 was fed on a commercial diet supplemented with sodium selenite (0.30 mg kg(-1) feed), group T2, T3 and T4 were fed on a commercial diet supplemented with nano-selenium (0.15, 0.30 and 0.60 mg kg(-1) feed, respectively). Sperm characteristics (sperm count, motility, viability, and maturity) as well as testicular histomorphometric features [tubule differentiation (TDI), spermiation (SPI), Sertoli cell (SCI) and meiotic (MI) indices] were assessed. The results showed that sperm characteristics were gradually decreased with age in the control group, however, it increased in group T3. Also, TDI, SPI, SCI, and MI in group T3 were higher than those of other groups. Our findings revealed that dietary supplementations with nano-selenium boosted fertility in aged male broiler breeders and the best results were obtained when the roosters received 0.30 mg kg(-1) nano-selenium. Supplementation of nano-selenium in aged broiler breeder males might be effective to maintain flock fertility and/or increase the flock fertility.