Effects of water additive probiotic, Pediococcus acidilactici on growth performance, feed utilization, hematology, gene expression and disease resistance against Aspergillus flavus of Nile tilapia (Oreochromis niloticus)

Probiotics are live beneficial Micro-organism introduced into the gastrointestinal tract through food or water, probiotics confer several benefits and play important roles in improving growth performances, disease resistance, immunity, health status, gut microbiome, and water quality. The present study examined the effects of water additive probiotic, Pediococcus acidilactici, on growth performance, feed utilization, hematology, gene expression, and disease resistance in tilapia Oreochromis niloticus fingerlings challenged with fungus (Aspergillus flavus). Triplicate groups of Nile tilapia fingerlings (20.0 ± 0.4 g) were fed a commercial diet in four water treatments control (0 g/m3), 0.1PA (0.1 g//m3), 0.2PA (0.2 g/m3) and 0.3PA (0.3 g/m3) of P. acidilactici respectively. The water quality parameters particularly total ammonia nitrogen (TAN) and ammonia (NH3) decreased significantly (P ≤ 0.05) in all three water treatments 0.3PA treatment was the lowest) when compared to the control treatment. The highest significant values (P ≤ 0.05) of growth performance, feed utilization and hematology recorded of either 0.2PA or 0.3PA group, in addition, the expression of innate immune genes were significantly upregulated (P ≤ 0.05) of tilapia fingerling at 0.3PA group compared to the control. The results also showed that juveniles reared in three water treatments with additive probiotics had a significantly lower (P ≤ 0.05) mortality when challenged with Aspergillus flavus. Hence, the water additive probiotic used in this study is a promising solution as an alternative product to improve the water quality, growth, and health of O. niloticus.