The potential of two vegetable-carried blood meals as protein sources in African catfish ( Clarias gariepinus, Burchell) juvenile diets

Abstract

The study was designed to determine the growth response of African catfish (Clarias gariepinus) juveniles on diets with two vegetable-carried blood meals (brewers’ dried grains with blood meal (BB) and rumen contents with blood meal (RB)) as protein sources and alternatives to imported commercial fish feed (CatCo®). Diets, with BB and RB included at 10%, formulated to supply 45% crude protein and 4,300 Kcal di-gestible energy/kg in similarity with CatCo®, were used in a 49-day trial in plastic tanks (L × B × H: 53 cm × 37 cm × 29 cm; capacity 50 liters). Juveniles were evaluated in terms of mean final body weight (MFBW), mean weight gain (MWG), average daily gain (ADG), specific growth rate (SGR), average daily feed intake (ADFI), feed conversion ratio (FCR), protein efficiency ratio (PER), feed cost/g gain (FCGA), and mortality (as % survival). CatCo® was superior (P < 0.05) to BB and RB diets in supporting MFBW, MWG, ADG, FCR, SGR, ADFI and mortality. However, CatCo® was similar (P > 0.05) to BB in PER but inferior in FCGA (0.46 vs. 0.36 Naira/g gain; 1 US$ = N150). RB was similar (P > 0.05) to BB in PER but least economical in FCGA. The study demonstrated the potential of vegetable-carried blood meals from brewers’ dried grains and dewatered rumen contents as alternatives for use as feed for African catfish especially juve-niles.