Probiotic supplementations improve growth, water quality, hematology, gut microbiota and intestinal morphology of Nile tilapia

A 75-day long experiment was performed to evaluate the effects of probiotic supplementations on rearing water quality, hematology, intestinal morphology, and gut bacterial load of Nile tilapia, Oreochromis niloticus. Fifteen ponds were used for 5 treatments with 3 replications, and 400 fingerlings per pond were fed with pre-starter feed twice a day at 5–8% of body weight. First treatment (T1) was supplemented with the soil probiotic Super PS/ week, T2 was designed to add gut probiotic Zymetin with feed, T3 contained half of the recommended doses of soil, gut, and water probiotics pH FIXER, T4 was planned to supplement with pH FIXER/ week, and no probiotic was used in T5 (control). Growth parameters (net weight gain, weight gain (%) and specific growth rate (%), SGR), survival, feed utilization (feed conversion ratio, FCR and feed conversion efficiency, FCE); water quality (dissolved oxygen, DO, free ammonia, temperature, alkalinity and pH), hematological parameters (RBC, WBC, hemoglobin, glucose, mean corpuscular hemoglobin, MCH), gut bacterial load and intestinal histomorphology (villi length, and enterocyte height) were analyzed fortnightly by sacrificing 3 fish/ treatment. Significant improvements in water qualities, growth performance, feed utilization, hematological parameters, intestinal microbial load and morphology were found with probiotic supplemented treatments than the control group where supplementation of gut probiotic (T2) and combination of soil, gut and water probiotics (T3) significantly augmented growth performance and feed utilization with improved gut microbiota and intestinal morphology. Hence, the findings recommended probiotic supplementation as an eco-friendly health management approach for tilapia aquaculture.