The effects of probiotics-supplemented diets on Asian sea bass (Lates calcarifer): Growth performance, microbial flora, digestive enzymes activity, serum biochemical and non-specific immune indices

The present research aimed to investigate the effects of probiotic bacteria isolated from fish intestines of Khuzestan, Bushehr and Hormozgan provinces on growth performance, microbial flora, digestive enzymes activity, serum biochemical and non-specific immune indices of Asian sea bass (Lates calcarifer). Four experimental groups were tested: control group (without probiotic), Diet 1 (probiotic bacteria isolated from Asian sea bass intestines in Khuzestan province), Diet 2 (probiotic bacteria isolated from Asian sea bass intestines in Hormozgan province) and Diet 3 (probiotic bacteria isolated from Asian sea bass intestines in Bushehr province). Fish sampling was performed on days 30 and 60 of the experiment. Results revealed that the use of the different dietary administration of probiotic bacteria significantly improved growth indices and increased the alpha-amylase, protease, lipase and alkaline phosphatase (ALP) activities of the L. calcarifer. Serum alternative complement, lysozyme, respiratory burst activities and glucose levels of those fish received diet included with probiotic bacteria significantly increased. At the end of the trial, fish fed diet containing probiotic bacteria had a significant increase in the total aerobic heterotrophic bacteria and Lactobacillus spp counts compared to the control group. The findings of this research suggest that the dietary administration of probiotic bacteria, particularly in the Diet 2 group (Hormozgan Province), could modulate the growth performance, non-specific immune response, microbial flora and digestive enzymes activity of L. calcarifer during 60 days.