EFFECTS OF DIFFERENT DIETARY FEED ADDITIVES ON GROWTH PERFORMANCE AND NON-SPECIFIC IMMUNE RESPONSES OF NILE TILAPIA Oreochromis niloticus

A 6-week feeding trial was conducted to investigate effects of dietary supplementation of four different feed additives on growth and non-specific immune responses of Nile tilapia, Oreochromis niloticus. Twenty fish were randomly distributed into 21 rectangular 30 L volume tanks. Nile tilapia averaging 4.89±0.07 g (mean±SD) were fed until satiation with one of the seven experimental diets. A basal diet without feed additives was used as control (Cont), shrimp soluble extract supplementation at 1% (SSE1), shrimp soluble extract supplementation at 2% (SSE2), combining 98% shrimp soluble extract and 2% inosine monophosphate (SSE+IMP2%) with supplementation at 2% in diet, combining 96% shrimp soluble extract and 4% inosine monophosphate (SSE+IMP4%) with supplementation at 2% in diet, 2% squid soluble extract (SQUID) and 2% tilapia soluble extract (TSE). At the end of the 6-week feeding trial, weight gain (WG) and specific growth rate (SGR) of fish fed diet SSE1 were significantly higher than other groups. However, there were no significant differences in WG and SGR between the Cont group and all the other groups. Feed efficiency (FE) of fish fed diet Cont was significantly higher than SSE2, SSE+IMP2% and SSE+IMP4% diets. However, there were no significantly differences between fish fed diets Cont, SSE1, SQUID and TSE. The results of this study indicated that addition of 1% shrimp soluble extract in diet of Nile tilapia could have beneficial effects on growth performance and feed utilization.