Production characteristics of pond-raised channel catfish Ictalurus punctatus fed diets with and without animal protein for three growing seasons

An experiment was conducted to determine the long-term effects of an all-pl ant-protein diet on production characteristics (harvest yield, dressing per centage, and body composition) of catfish Ictalurus punctatus taken from to p-harvested, multiple-stocked ponds over a 2.5-yr period of continuous prod uction. Fish in eight 0.08-ha ponds were fed an extruded, 32% protein contr ol diet (CON) containing animal and plant proteins, while fish in eight rep licate ponds were fed an isonitrogenous diet containing only plant proteins , primarily from cottonseed meal and soybean meal (APP). Diets were fed onc e daily to apparent satiation during the growing season. Ponds were top-har vested twice per year in the spring and fall and partially restocked after each harvest. CON-fed fish received 13,335 kg of feed during the 2.5-yr per iod. APP-fed fish received 13,506 kg of feed. Total yields were 5,562 kg of CON-fed fish and 5,840 kg of APP-fed fish; average annual yields were 3,47 7 kg/ha per yr and 3,650 kg/ha per yr, respectively (P > 0.05). Feed conver sion ratios, 2.5 for CON-fed fish and 2.6 for APP-fed fish, did not differ significantly (P > 0.05). Live weights at harvest averaged 529 g (CON) and 481 g (APP), and were not significantly different. Dressing percentages wer e 59% for fish fed both diets (P > 0.05). APP-fed fish had less (P < 0.05) visceral fat and less (P < 0.05) muscle lipid than CON-fed fish. Results in dicate that a lysine supplemented, allplant-protein diet containing 40% cot tonseed meal and 20% soybean meal is suitable for long-term production of c hannel catfish in earthen ponds and such a diet can reduce the fat content of pond-reared fish.