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Abstract
The current study was conducted to evaluate the effect of adding inactive or active dried yeast (Saccharomyces Cerevisiae) into laying hen diets on their performance and egg quality. For this purpose a total number of 900 white Hy line hens 24 weeks old were divided into nine treated groups of 100 laying hens each. For 16 weeks experimental period the groups were fed on basal diet supplemented with 5 graded levels of active or inactive dried yeast as 0.0% (control), 2%, 4%, 6% and 8%. These experimental diets were formulated to be iso-caloric. The obtained results showed that:
1- Adding yeast either inactive or active to layer diets at most tested levels increased both egg production and egg weight compared to the control group.
2- Adding yeast culture to layer diets at most tested levels significantly reduced the average feed intake and significantly (P≤0.05) improved feed conversion ratio compared to the control group.
3- Values of most egg quality traits especially shell thickness, yolk index and shape index were not affected significantly by suppling layer diets with either inactive or active yeast at most tested levels in comparison to the control group.
4- Suppling layer diets with inactive or active yeast at each tested level improved both crude protein and ether extract digestibilities and nitrogen balance % compared to the control group.
Conclusively, it could be recommended to incorporate 2% inactive yeast or 6% active yeast into laying hen diets for improving their performance, egg quality and economic efficiency.