Effects of Dietary Supplementation of a Single-and a Multi-Strain Probiotic on Growth Performance and Intestinal Histomorphology of Commercial Broiler Chickens

Abstract

Background and Objective: The effects of dietary supplementation of a multi-strain probiotic (MSP) (Bacillus subtilis, B. coagulans, B. licheniformis and Clostridium butyricum HJCB998) on growth performance and intestinal mucosal architecture of broiler chickens were compared with a Bacillus subtilis PB6 (BSPB6) based single strain probiotic through an experiment which lasted for 42 days involving 400 straight run flock of Vencobb chickens. Materials and Methods: The chicks having an initial mean body weight (BW) of 42.6±0.5 g were randomly allocated to four dietary treatments each consisting of ten replicates (n = 10 chicks/replicate) and were fed with a basal diet devoid of any growth promoter (negative control, NC), the basal diet supplemented with 0.2 g kg^–1 BSPB6 (BSPB6) and the basal diet supplemented with MSP either at 0.5 g kg^–1 (MSP 0.5) or 1.0 g kg^–1 (MSP 1.0). Results: The birds fed with the MSP 0.5 and MSP 1.0 diet were found to have numerically better (p = 0.230) BW and average daily body weight gain (ADG) vis-α-vis the BSPB6 and NC group. It was also observed that a higher dietary inclusion of MSP (MSP 1.0) did not yield any additional benefit. Supplementation of the BSPB6 or MSP either at 0.5 or 1 g kg^–1 feed numerically improved (p = 0.638) villus height (VH). However, the effects of these dietary treatments on crypt depth (CD) and VH/CD ratio was not conspicuous (p>0.05). Analysis of economics of feeding different diets indicated that MSP 0.5 group had superior return on feed cost (INR) per kg BW due to numerical improvement (p>0.05) in growth performance than other dietary treatments and control. Conclusion: It was concluded that dietary supplementation with MSP yielded better return on investment than BSPB6 and the effects might be mediated through a better BW and moderate positive impacts on intestinal mucosal architecture.