Effect of dietary Bacillus subtilis, dried whey powder, and Saccharomyces cerevisiae on the production performance, egg quality, blood biochemical parameters, and ileal histomorphology in late-phase Lohmann LSL- lite laying hens.

The current study was conducted to investigate the effects of dietary whey powder (WP), Bacillus subtilis (B. subtilis), and Saccharomyces cerevisiae (S. cerevisiae) and their combination on the production performance, egg quality, blood biochemical and ileum histomorphology parameters of Lohmann laying hens. A total of 288 Lohmann LSL-Lite laying hens (75 wk) were randomly allocated to 8 treatments with 6 replicates of 6 hens each, over a 12-week period. A 2 × 2 × 2 factorial arrangement was used, consisting of a basal corn-soybean meal diet with two levels of B. subtilis (0 and 1 g/kg diet, 10 CFU), two levels of WP (0 and 1 g/kg diet), and two levels of S. cerevisiae (0 and 3 g/kg diet, 5 × 10 CFU). The control group received a standard diet without any additive. No significant three-way interaction among WP, B. subtilis, and S. cerevisiae was observed for the studied parameters, except for malondialdehyde level (P < 0.05), where a significant three-way interaction was detected, resulting in reduced malondialdehyde concentrations (P = 0.028). The simultaneous inclusion of WP and B. subtilis improved ileum villus length and serum calcium levels. A significant two-way interaction between WP and B. subtilis indicated a synergistic effect on egg production, weight, and mass during 75-80 weeks (P < 0.05). In conclusion, it seems that the simultaneous use of WP and B. subtilis is effective in improving performance and ileum histomorphology in Lohmann laying hens in the late production phase.