Canola meal as an alternative protein source in diets for fry of tilapia (Oreochromis niloticus)

Abstract

Canola meal was used to replace fishmeal protein in diets for fry of tilapia (Oreochromis niloticus L. 1758) at rates of 0 (control), 10%, 20%, 30%, 40%, and 50%. The diets contained approximately 30% crude protein and 3000 kcal/kg digestible energy. The fry were fed 90 days and the growth, feed conversion ratio, protein efficiency ratio, hepatosomatic index, renosomatic index, and body composition were determined. The final weight (5.12 g) and feed intake (7.99 g) of fry fed the 10% diet did not significantly differ from those of the control. Weight gains declined beyond this replacement level, probably because of increased levels of antinutritional factors, particularly glucosinolates. Whole body percentages for moisture, crude lipid, crude protein, and ash were unaffected by the dietary treatment. Results indicate that protein from canola meal can replace up to 10% of protein from fishmeal in diets for tilapia fry.