GROWTH PERFORMANCE OF AFRICIAN CATFISH (CLARIAS GARIEPINlJS) FINGERLINGS FED PROCESSED SOYBEAN MEAL-BASED DIET, SUPPLEMENTED WITH PHYTASE

Abstract

A 77-day feeding trial was conducted to evaluate the growth performance of African catfish (Clarias gariepinus) fingerlings (7.0±1.09) fed variously processed Soybean meal-based diets, supplemented with 8000 units phytase per kg diet. Six experimental diets were formulated using raw soybean meal without phytase supplement as control (diet! k raw soybean meal with phytase supplement as the reference diet(diet 2), oven dried soybean meal plus phytase supplement(diet 3), cooked. soybean plus phytase(diet 4), toasted soybean plus phytase( diet 5) and soaked soybean plus phytase( diet6) Evaluation of diets was carried out on the basis of fish growth response, protein utilization, feed conversion and protein digestibility. Fish treated with diets 5 and 4 differed significantly (P<0.05) from fish fed other diets in their mean weight gain, feed conversion ratio, protein efficiency ratio, digestibility, protein productive value and specific growth/rate (SGR). Fish fed diet 1 (control diet) and 2 (reference diet) showed no significant differences (P>0.05) in mean weight gain, specific growth rate and protein efficiency ratio, but significant differences (P<0.05) in feed intake, feed conversion ratio, protein utilization and digestibility. Fish fed diets 2 and 6 exhibited no significant differences (P>0.05) in feed conversion ratio, protein productive value and protein digestibility of the fish, but differed significantly (P<0~05) in mean weight gam, feed intake and protein efficiency ratio. In conclusion, the diet which ,contained toasted soybean meal supplemented with 8000 '-units per kg phytase is moste~onomically and environmentally suitable for raising Clarias gariepnus fingerlings.