LAUSR

ABSTRACT The study was designed to evaluate the effect of dietary L-lysine supplementation on growth performance and feed utilization of African catfish fingerlings fed diet containing high levels of slaughterhouse poultry by-product meal (SPB). Control diet (CD) without amino acid supplementation or SPB inclusion contained 40% of fish meal (FM) and 20% of soybean meal (SBM), four isonitrogenous and isocaloric diets formulated to represent two levels of SPB (50% and 75%) with two levels of L-lysine supplementation (0.0 and 1.0%), SPB50%0.0, SPB50%1.0, SPB75%0.0 and SPB75%1.0, where the subscripts and superscripts refer to the replacement level of FM with SPB and L-lysine supplementation level respectively. Growth performance and feed utilization in terms of final body weight (FBW), weight gain (WG), feed intake (FI), and specific growth rate (SGR) tended to decrease as SPB levels increased from 50% to 75% with or without L-lysine supplementation. Protein retention (PR) was not significantly different between fish fed CD and those fed SPB50%0.0. Energy retention (ER) was not significantly different between fish fed CD and those fed SPB50%0.0 and SPB75%1.0. Lipid, protein, moisture, and ash of fish fed the experimental diets were not statistically significantly different than the control diet. The partial replacement of FM at the rate 50% and 75% with SPB is possible in diets for African catfish, especially with 1% L-lysine supplementation, and could match growth performance of FM diets, as well as minimize feed cost and improve profitability.