Effect of probiotic Bifidobacterium animalis as an alternative to growth-promoting antibiotics on performance, egg quality, and health parameters in young laying hens

Abstract Probiotics are live microorganisms that promote the selective growth of beneficial bacteria in birds and can be an effective alternative to growth-promoting antibiotics (GPAs) in poultry. The present study was conducted to determine the effects of dietary probiotics in the diet of early phase laying hens on laying performance, egg quality, blood parameters, and organs morphological characteristics. Seventy-two 13-week-old Lohman White hens were randomized into three dietary groups feed diets with GPA (0.5% of COLI-ZIN), probiotic (PRO; 0.1% Bifidobacterium animalis ssp lactis) or without additive (control; CON) for a 90-days feeding trial. Significant differences were observed in feed intake and feed conversion ratio in PRO with respect to GPA and CON at 90-days treatment (p<0.05). PRO-treated group improved egg weight compared with the GPA and CON groups, but with no statistically significant difference. The air cell height, yolk volume, and yellowness of yolk color were lower, and thick and thin albumen were greatest in PRO than CON and GPA groups (p<0.05). Dietary PRO decreased the number of heterophils and increased the number of lymphocytes, improving the H/L index significantly (p<0.05). PRO treatment increases the relative weight of crop and duodenum compared to GPA (p<0.05). No significant changes in the relative weight of reproductive organs were observed. Based on the results of the present study, it can be concluded that, Bifidobacterium animalis ssp lactis supplementation can be used as a safe alternative in young laying hens.