Fertility is one of the most important parameters in breeder farms and cockerels play an outstanding role in the fertility of eggs in broiler breeder farms. Todays, supplementation of chicken diet with additives such as organic selenium is used to increase fertility. The aim of this study was to evaluate the effects of different levels of nano-selenium (Nano-Se) on the expression of molecular markers of spermatogonial stem cells (SSCs) in the testis of broiler breeder males. A total of 30 roosters of 40 weeks of age were randomly divided into five groups. Groups were as follows: 1) control (normal diet) group, 2) diet supplemented with 0.30 mg kg-1 sodium selenite, 3) diet supplemented with 0.15 mg kg-1 Nano-Se, 4) diet supplemented with 0.30 mg kg-1 Nano-Se, and 5) diet supplemented with 0.60 mg kg-1 Nano-Se. At the end of the experimental period (5th week), birds were autopsied and samples from testis of all birds were collected. The testis samples were used to examine the β1-integrin (CD29), thy-1 (CD90) and NANOG mRNA expression by real-time PCR. The results showed that testis of the groups fed with the diets supplemented with 0.60 mg kg-1 and 0.15 mg kg-1 of Nano-Se had the highest and lowest mRNA expression of SSCs markers, respectively. In conclusion, the present study indicated that Nano-Se had advantages over sodium selenite. Diet supplemented with 0.60 mg kg-1 of Nano-Se may contribute to optimal fertility via increasing the mRNA expression of SSCs markers of roosters' testis and could be used to delay the reduction of fertility caused by aging in broiler breeder males.
Keywords: Broiler breeder males; Molecular markers; Nano-selenium; Spermatogonial stem cells.