Effects of Bacillus subtilis PB6 supplementation on productive performance, egg quality and hatchability in broiler breeder hens under commercial farm condition.

The aim of the present study was to determine the effects of Bacillus subtilis PB6 supplementation on productive performance, egg quality and hatchability of broiler breeder hens. A total of 20,000 broiler breeder hens (ROSS 308), 57 weeks old, were assigned to the two equal groups as follows: The first group was fed a basal diet and the second group was fed the basal diet that supplemented with the Bacillus subtilis PB6 (2 × 107 cfu/g) at the rate of 1 g/kg of diet. Results indicated that adding Bacillus subtilis significantly improves egg production (P < 0.05). The body weights and egg weight were not affected by the dietary treatments (P > 0.05) but Bacillus subtilis improved the egg haugh unit (P < 0.05). Adding Bacillus subtilis significantly increased hatching egg, eggshell thickness and egg hatchability (P < 0.05). A highly significant improvement was noticed in the faecal score of the group fed with Bacillus subtilis (P < 0.01). Adding Bacillus subtilis increased the level of total cholesterol (P < 0.01) and decreased the blood heterophil to lymphocyte ratio (P < 0.01) in breeders' serum. It is concluded that Bacillus subtilis PB6 supplementation at the level of 1 g/kg of broiler breeder diet, significantly improve the egg production, egg quality, hatchability, faecal score and return on investment. [ABSTRACT FROM AUTHOR]