Oxidative status, immune response and growth performance of broiler chickens treated with different multi-strain probiotics

This study was conducted to evaluate the effects of different sources of probiotics (based on Lactic acid bacteria or Bacillus strains) on growth performance, antioxidant status and immunity. Therefore, two hundred eighty-eight 1-d-old male Ross broiler chicks were allocated to three experimental groups for 35 days. The dietary treatments included: basal diet-unsupplemented (C), supplemented with lactic acid bacteria (LABP), and/or Bacillus strains-based probiotics (BP). LABP led to reduced feed intake, while both LABP and BP improved the feed conversion rate as compared to the control group on day 7 (P < 0.05). BP increased serum total protein level compared to the control group at the end of the experiment (P < 0.05). However, supplementation with probiotics did not affect the relative weight of carcass components, immune organs, malondialdehyde, reactive oxygen species levels and the heterophil/lymphocyte ratio. These findings suggest similar efficacy and potency between probiotics based on Bacillus strains-based and lactic acid bacteria-based probiotics in enhancing early-life growth performance and increasing blood total protein. However, there is insufficient evidence to support an improvement in antioxidant status or modulation of the immune system through the addition of LABP or BP.