Saeed Ashrafi , Habib Aghdam Shahryar , Abolfazl Gorbani , Payam Panahi moghaddam and Mehdi Salmanzadeh
The impacts of supplemental L-threonine in broiler breeder molting hen diets were evaluated. 600 hens were obtained from (Cobb-500) broiler breeder strain at 60 weeks of age. All hens were collected from the same breeder flock and weighed on a balance with 10 g precision. At 60 weeks of age, hens based on a completely randomized design were divided into 5 treatments with 4 replicates per treatment and 30 hens and 3 roosters per replicate. Control hens were fed a corn-soybean commercial broiler breeder molting diet containing 0.48% threonine (Thr). Experimental diets containing, basal diet with 0.52, 0.57, 0.62, and 0.67% Thr were fed. Egg samples were analyzed for egg weight, egg production and hatching traits in newly-hatched chickens. The results of the study indicate that, egg production increased with increasing dietary threonine levels up to 0.67% Thr in the diet. But, the weight of eggs was significantly lower than control. Dietary L-threonine supplementation didn’t show any significant effect on hatchability of broiler breeder molting hens from 60 to 63 weeks of age. Weight of newly-hatched chickens was significantly lower when supplemental L-threonine in broiler breeder molting hen diets from 60 to 63 weeks of age were received than control group. These data clearly indicate a potential important impact on egg production by increasing dietary threonine nutrition of a broiler breeder molting hen.
