Effects of substituting plant-based protein sources for fish meal in the diet of Nile Tilapia (Oreochromis niloticus)

The purpose of this study was to evaluate the nutritional adequacy and suitability of rice polish and mustard oil cake as protein sources in the diet of Nile Tilapia (Oreochromis niloticus). To assess the growth performance and feed utilization of Nile Tilapia, three diets containing rice polish (0, 8, and 16%) and mustard oil cake (8, 16, and 24%) were formulated and fed to the fish over a period of 60 days. According to the findings, the growth performance tended to decline as the levels of rice polish and mustard oil cake increased. The control diet (30% Fish meal) resulted in the highest weight gain (373.79±49.78%), whereas the diet (20% Fish meal) resulted in the least weight gain (341.24±27.23%). The specific growth rate (SGR) followed the same pattern, and there were no statistically significant differences in SGR between diets (p>0.05). At the end of this trial, the feed intake (FI) of the various diets ranged between 32.37 g and 37.78 g per fish. Although feed conversion ratio (FCR) and protein efficiency ratio (PER) were not significantly different among diets (p>0.05), feed intake decreased as the incorporation of rice polish increased.