Evaluation of dietary Heat-killed Lactobacillus plantarum strain L-137 supplementation on growth performance, immunity and stress resistance of Nile tilapia (Oreochromis niloticus)

摘要

Four feeding trials were carried out to investigate the effect of immunobiotic (Heat-killed Lactobacillus plantarum strain L-137-HK L-137) supplement in diets on growth, immune responses and stress resistance of Nile tilapia (Oreochromis niloticus). For the growth evaluation, three different feeding regimes allocated for tilapia juveniles including 0, 10, 20 and 50 ppm concentrations of HK L-137 for the first 50-day feeding period, and then fish were continuously fed diets with reduced HK L-137 levels of 0, 2, 4 and 4 ppm, respectively for 70 days, and finally the last feeding period prolonged for 30 days without HK L-137 in diets. In terms of the immunity test, fish were exposed to ammonium chloride and Streptococcus agalactiae to investigate the immune responses and stress resistance.