Methionine-supplemented Soybean Meal for Catfish

Two experiments were conducted to evaluate the effects of methionine-supplement soybean meal on the growth of catfish (Silurus meridionalis). In the first experiment, six levels (0, 11.6, 23.1, 34.7, 46.3, and 57.9%) of solvent extracted soybean meal replaced fish meal in an isonitrogenous (48% crude protein) and isoenergentic (20KJ/g gross energy) diets. The six diets were fed to triplicated tanks of ten fish weighing about 24 grams. Results indicated that 39% of the fish meal protein could be replaced with soybean meal in the diets of southern catfish without significantly reducing growth. In the second experiment, seven diets were formulated to examine the effects of methionine supplementation on the growth performance of catfish weighing about 20 grams. The diets were formulated so that soybean meal replaced either 39 or 52 percent of the fish meal. The results indicated no significant differences in feeding rate; digestibility and growth rate between fish fed the diets containing 39 percent soybean meal with or without methionine. Supplementing methionine to the 53 percent soybean meal diets resulted in significantly (P<0.05) higher growth rates and feed conversions in the fish compared to those without supplemental methionine. These results indicate that at high levels of soybean meal replacement of fish meal in catfish diets, methionine may be a limiting amino acid needed to maximum growth and feed utilization.

Ai, Q.H. and X.J. Xie. 2005. Effects of replacement of fish meal by soybean meal and supplementation of methionine in fish meal/soybean meal-based diets on growth performance of the southern catfish Silurus meridionalis. J. World Aquaculture Soc. 36(4): 498-507.