APPARENT DIGESTIBILITY OF NUTRIENTS IN COMMERCIAL AQUAFEEDS BY THE AFRICAN CATFISH, CLARIAS GARIEPINUS (BURCHELL 1822)

Abstract

Commercial aquafeeds FA, FB and FC were obtained from renowned aquafeed store in Akure. Apparently healthy catfish were distributed into nine rectangular glass tanks (60 x30 x20 cm) at 12 catfish per tank of average weight 4.13 g. The experimental design was Completely Randomized Design. Each aquafeed was fed by hand to three groups of catfish in three replicates for 84 days. The catfish were fed twice daily at 08:00-9:00 hours and 16:00-17:00 hours. All groups were fed their respective diets to satiation. Each group of fish was batch-weighed weekly using electronic weighing balance Toledo PB 8001, London. Catfish faecal samples were collected by sieving water using muslin cloth. The faecal samples were air-dried at ambient temperature of 26 o C prior to analyses. The proximate composition of the aquafeeds and faecal samples were determined according to the procedures of AOAC 1990. Growth performance and nutrient utilization were estimated using standard procedures in fish nutrition. Water quality parameters which include pH, temperature and dissolved oxygen concentration were determined weekly. At the end of the 84 days feeding trial, growth performance, nutrient utilization, fish carcass composition and apparent nutrient digestibility were determined. The values of apparent digestibility of protein for the three commercial aquafeeds obtained during the experiment ranged from 51.30 in feed C to 60.29 in feed A while the lipid digestibility values ranged from 53.52 in feed B to 64.10 in feed A. The good performance of catfish fed feed type B growth indicates that the feed contained a well-balanced nutrient, high digestibility and nutrient utilization.