Effects of Direct Fed-Microorganisms and Enzyme Blend Co-Administration on Growth Performance in Broilers Fed Diets With or Without Antibiotics

Direct-Fed Microorganisms (DFM) and exogenous enzymes have been demonstrated to improve growth performance in poultry and are potentially important components of management programs for antibiotic-free (ABF) poultry production. In this study, we evaluated the effect of a feed additive composed of a DFM product containing spores of 3 Bacillus amyloliquefaciens strains and a multi-enzyme complex of xylanase, amylase, and protease on the performance of broilers with or without an antibiotic growth promoter (AGP), either bacitracin methylene disalicylate (BMD) or virginiamycin. Growth performance of broilers fed one of 6 treatments arranged in a 3 (AGP) × 2 (additive) factorial was evaluated over a 42 d production period. Overall, administration of the feed additive improved body weight, body weight gain, and feed conversion ratio. Administration of either antibiotic significantly reduced cumulative FCR when compared to the control, while BMD administration reduced foot pad lesions as compared to the control. Our results suggest the co-administration of DFM and enzymes may be an important component of ABF poultry production programs and the benefits of their use are not dependent on the presence or absence of AGP.