Nile tilapia (Oreochromis niloticus) is one of the most widely farmed fish species globally, contributing significantly to nutrition and economic growth, particularly in developing regions. This study examined the effects of diets containing 5%, 7% and 10% fish meal on the growth performance of O. niloticus under controlled aquaculture conditions for 90 days. Fish that fed a 10% fish meal diet (T3) had the best growth performance as compared to other treatment groups. The T3 group showed a significant increase in body weight and body length, which were significantly higher (P < 0.05) compared to control, T1 and T2 groups (178.92%, 97.64% and 120.96% respectively). This significant improvement in body weight and length illustrates that a 10% of fish meal inclusion rate has been the optimal point of growth efficiency of Nile tilapia, presumably because it increases protein supply and nutrient utilization. The proximate analysis of Nile tilapia also indicate that the high concentration of moisture (80.77 ± 0.81), ash (4.28 ± 0.07), crude fat (3.29 ± 0.11) and Crude Protein (63.06 ± 0.56) was recorded in T3 among the other diet treatments. The results suggest that moderate fish meal supplementation can enhance growth level and sustainable aquaculture production.
