The study investigated the effect of dietary inclusion of different proportion of heat treated and heat untreated Jatropha curcas kernel meal (JCKM) on growth performance, feed utilization efficiency and survival rate of juvenile Nile tilapia. Ten fish with an average body weight of 2.36 g fish-1 were randomly distributed in each experimental aquarium in triplicates, and fed with experimental diets for 65 days. The results revealed that the highest growth performance in terms of final body weight and specific growth rate was observed on the fish fed with heat treated control diet followed by heat untreated control diet and 10% heat treated JCKM with same survival rate. Similarly, the best feed utilization efficiency in terms of feed conversion ratio and feeding efficiency was observed on the fish fed with heat treated control diet followed by 10% heat treated JCKM and heat untreated control diet.
All fish fed the above three diets had higher growth performance, feed utilization efficiency and survival rate without significant (P>0.05) variation to each other. However, fish fed with the rest of the experimental diets had significantly (P<0.05) lower. Thus, the inclusion of excess dietary JCKM (above 10% heat treated dietary JCKM and at any level of heat untreated dietary JCKM) depressed growth performance, feed utilization efficiency and survival rate of the fish. This implies that heat treatment has an effect on reduction of some of anti-nutritional factors and toxicants in JCKM. In conclusion, dietary inclusion of heat treated JCKM in fish diet increases growth performance and feed utilization efficiency of the fish without increasing mortality rare, and thus, it is a future promising feed ingredient for fish feed production.