Modulation of growth performance, immunological responses and disease resistance of juvenile Nile tilapia ( Oreochromis niloticus ) (Linnaeus, 1758) by supplementing dietary inosine monophosphate

This study was investigated to examine supplemental effects of dietary inosine monophosphate (IMP) on growth performance, feed utilization, biochemical, hematological and immunological parameters of juvenile Nile tilapia Oreochromis niloticus. Disease resistance to experimental infection with Streptococcus agalactiae was also assessed. A semi-purified basal diet was supplemented with 0 (IMP0, Control), 1 (IMP1), 2 (IMP2), 4 (IMP4) and 8 (IMP8) g purified IMP kg−1 diet to formulate five experimental diets. Each diet was randomly allocated to triplicate groups of fish (0.59 g) for 60 days. The results indicated that supplementation of IMP significantly (P 0.05). Among whole body proximate composition and somatic parameters, condition factor was significantly influenced by dietary supplementation of IMP. A wide variation in hematological parameters were observed and dietary supplementation increased the hematocrit content (P 0.05). Total serum protein (TSP), lysozyme activity (LA), superoxide dismutase activity (SOD) and bactericidal activity (BA) tended to increase with the supplementation of dietary IMP. TSP and SOD were significantly improved with ≥4 g kg−1 supplementation, while LA with 8 g kg−1 and BA with ≥1 g kg−1 supplementations. IMP supplemented groups showed higher (P > 0.05) cumulative survival compared to that of supplementation free control group. IMP supplemented diet groups also showed significantly higher BA in the post challenge test. Based on the overall performances, the results of the current study indicated that the inclusion of IMP in Nile tilapia diet can improve growth performance, feed utilization, haematological and immunological parameters; and disease resistance of juvenile Nile tilapia