EFFECT OF DIFFERENT LEVELS OF SELENIUM-ENRICHED SACCHROMYCES CEREVISIAE ON THE PRODUCTION PERFORMANCE, EGG QUALITY, LIPID PROFILE, ANTIOXIDANT STATUS, AND INTESTINAL MICROBIAL STRUCTURE OF LAYING HENS UNDER HOT CONDITIONS

This study aimed to investigate the effects of different levels of selenium-enriched Saccharomyces cerevisiae (S. cerevisiae) on the production performance, egg quality, lipid profile, antioxidant status, and intestinal health of laying hens under hot environmental conditions. A total of 200 healthy 23-wk-age Brown Lohmann layers were randomly divided into 4 treatments, each in 5 replicates as follows: the first group (Se-ES0) fed the basal diet without supplementation (control), the second group fed the basal diet supplemented with 0.25 g selenium-enriched S. cerevisiae (Se-ES1), the third group fed the basal diet supplemented with 0.5 g selenium-enriched S. cerevisiae (Se-ES2), the fourth group fed the basal diet supplemented with 1.0 g selenium-enriched S. cerevisiae (Se-ES3). After 8 weeks, the results showed a deterioration in the productive performance and egg quality of laying hens fed on a diet without additives under heat stress conditions (P < 0.05). Compared with the control group, the feed conversion ratio (FCR) improved (P < 0.05), and the egg production%, albumen weight, albumen height, and Haugh unit in the Se-ES2 and Se-ES3 groups increased significantly (P < 0.05). Furthermore, the antioxidant capacity in the Se-ES3 group was enhanced than that in the other groups (P < 0.05) decreased MDA and increased SOD levels. Additionally, the lipid profile improved in the Se-ES3 group (P < 0.05) by decreased cholesterol and increased HDL levels. Moreover, supplementation with Se-ES modified the microbial content, as the Lactobacillus count increased, and the E. coli and Coliform count decreased. It can be concluded, that adding selenium-enriched S. cerevisiae improved the egg production%, FCR, and Haugh unit and enhanced microbial community, lipid profile, and antioxidant status of heat-stressed laying hens.