Effect of Different Levels of Mineral and Vitamin Premix on Laying Hens Performance during the First Laying Phase

An experiment was conducted to evaluate the effects of different levels of mineral and vitamin premix on performance and egg traits of laying hens from 37 to 49 weeks of age. Two hundred and forty laying hens (Hy-Line W-36 strain) were randomly assigned to 5 dietary treatments of four replicates each with 12 hens per replicate). The levels of mineral and vitamin premixes in the experiment were 0, 0.15, 0.25 (as recom-mended by manufacturer), 0.35 and 0.45% of diets and fed to laying hens for 12 weeks. The results showed that the supplementation of different concentration of mineral and vitamin premix improved (P > 0.05) the performance of laying hens. The highest percentage of egg production (83.48), the highest amount of egg mass (47.89 g), the best feed conversion (ratio 2.09 g:g) and the lowest price for production per kilogram of (6760 Rials) were observed in group fed: 0.45% of mineral and vitamin premix. Different levels of dietary mineral and vitamin premix did not affect the eggs weight, the amount of daily feed intake and egg traits of laying hens. The overall results of the present study indicate that during the first phase of egg production in laying hens, increasing the levels of dietary mineral and vitamin premix up to 0.45% can improve the per-formance and reduce the feed cost of egg production.