عنوان مقاله [English]
An experiment was conducted to evaluate the effects of different levels of mineral and vitamin premixes on performance, egg traits and blood parameters of laying hens in late laying period on corn – soybean base diets. Experiment was carried out in a completely randomized design with 240 Hi-Line (W36) laying hens from 65-76 weeks of age with 5 treatments, 3 replicates and 12 hens in each replicate. The levels of mineral and vitamin premixes in experiment diets were 0, 0.25 (factory recommended level), 0.35%, 0.45% and 0.55% and fed to laying hens for 12 weeks. The results showed that using different levels of mineral and vitamin premixes significantly affect the performance and egg traits of laying hens (P0.05). The overall results indicated that in laying hens in late laying period on corn base diets, 0.45% of mineral and vitamin premixes can improve their performance and decrease the feed price for production each kilogram of egg.