Abstract: A 3 × 3 factorial feeding experiment was conducted to evaluate the optimal dietary protein and lipid levels of juvenile yellow catfish (Pelteobagrus fulvidraco) with average initial body weight of 10.32 g at water temperature of 23± 5℃. The juveniles were randomly stocked into 27 net cages of each 60 cm × 60 cm × 120 cm with flowing water, and fed nine practical diets containing three protein levels (32.0%, 40.0%, and 48.0%), and three fat levels (3.0%, 10.0%, and 17.0%) for 100 d. The for 100 days. The results showed that at 3.0% dietary lipid level, the significantly higher final body weight, and specific growth rate and lower food conversion ratio were found in the fish fed the diet containing 40.0% protein and 3.0% fat levels compared with other protein levels (P〈0.05). At 10.0% dietary lipid level, significantly lower food conversion ratio was observed in the fish fed the diet containing 48.0% and 40%pro- tein level (P〈0.05). The best apparent digestibility of dry matter was found in the fish fed the diet containing 48.0% protein and 3.0% fat levels and 40.0% protein and 10.0% fat levels (P〈0.01). There was the maximal protein digestibility in the fish fed the diet containing 48.0% protein and 3.0% fat levels (P〈0.01). Fat digestibility was the best in the 40% protein and 10% fat group (P〈0.01). It is suggested that the requirement of the juvenile yellow catfish be 40.0% for protein and 10.0% for fat.

Key words: yellow catfish, fat, protein, requirement