Nasiri K - Department of Animal Science, Sari Agricultural Sciences and Natural Resources University, Sari, Iran
Kazemi-Fard M - Department of Animal Science, Sari Agricultural Sciences and Natural Resources University, Sari, Iran
Rezaei M - Department of Animal Science, Sari Agricultural Sciences and Natural Resources University, Sari, Iran
Yousefi S - Department of Animal Science, Sari Agricultural Sciences and Natural Resources University, Sari, Iran

Effects of sodium selenite (SS) in offspring of broiler breeders has been reported, but the comparison between SS and different level of methionine on offspring has received limited, so this study was conducted to investigate sodium selenite and methionine effects on concentration of selenium in egg and serum of Iranian native broiler breeders. An experiment was conducted in 3 × 3 factorial experiment with three levels of sodium selenite (0.0, 0.3, and 0.5 mg/kg of diet) and three levels of methionine (0.23, 0.31 and 0.33 % of diet) to investigate reproductive performance and immune status of broiler breeders (64-74 wks). The higher methionine levels increased the egg weight until the dose of 0.31% of diet (P < 0.05). In this experiment, 0.5 mg/kg SS with 0.31 % methionine in the diet was found to increase egg weight (P < 0.05). The highest salable chicks were obtained by supplementing 0.3 mg/kg SS (P= 0.07). Increasing the level of methionine from 0.23 to 0.33% without SS and also, supplementation SS at 0.3 mg/kg with 0.33 % methionine exhibited higher serum selenium, although, no effect of methionine levels was observed on concentration of selenium in serum and transfer rate. Concentration of selenium in eggs and serum were significantly affected by interaction of SS and methionine levels in diet. An increment in glutathione peroxidase (GSH-Px) level tended to increase with SS (0.5 mg/kg) and methionine (0.33%) interaction (P=0.06). The results showed that increasing the level of methionine increases the immune response against influenza (AI) and Newcastle disease (ND) (P = 0.0001). These results suggest that higher level of methionine at 0.31% could improve egg weight and Influenza and ND titers, SS at dose of 0.5 could increase concentration of selenium in serum, whereas increasing of SS levels significantly raised embryonic mortality.

Methionine, Broiler breeder, Sodium selenite, Immune response, Antioxidant enzyme