Replacement of fish meal by plant protein sources in Nile tilapia (Oreochromis niloticus) diet: growth performance and utilization

The nutritional suitability and cost effectiveness of rice polish and mustard oil cake as protein sources in the diet of Nile tilapia (Oreochromis niloticus) were studied. This study introduced rice polish as a plant protein source for Nile tilapia and three diets were formulated using rice polish (0, 10 and 20%) and mustard oil cake (10.0, 17.6 and 22.0%) for a feeding trail of eight weeks to observe the growth performance and feed utilization. The result was indicated that growth performance tended to decrease with increase in inclusion level of rice polish and mustard oil cake. The control diet (FM35) recorded the highest body weight gain (BWG) (363.79±59.32%) and the least (330.24±32.32%) was in diet FM25. Specific growth rate (SGR) was followed the same trend and no significant differences of SGR was observed among the diets (P>0.05). Feed intake (FI) of different diets was ranged between 30.33 g and 35.08 g per fish at the end of this experiment. Feed intake was also declined with the increase in inclusion level of rice polish, though the feed conversion ratio (FCR) and protein efficiency ratio (PER) were not significantly different (P>0.05) among the diets. The results of this study revealed that partial replacement of fish meal by rice polish and mustard oil cake would be cost effective without any significant change in growth performance.