Channel catfish were stocked in 27, 1/10-acre ponds at the rate of 3,000 per acre and fed nine commercial-type rations containing three protein percentages and three levels of fish meal for 200 days. Average survival for the experiment was 96.8% and 93% of the fish were over 12 inches in length at harvest. Average yield for treatments ranged from 2,330 to 3,030 Ib/acre and the average for all treatments was 2,638 lb. The results indicated that satisfactory production can be obtained with all-plant rations. The 29%. all-plant protein diet yielded 2,330 Ib/ acre of harvestable size fish. Increasing total protein in the all-plant rations to 36 and 43% resulted in production of 2,475 and 2,640 lb/acre, respectively. Replacing 1/6 of the plant protein with fish meal protein, at the 29 per cent protein level, increased production by 100 Ib/acre; however, replacing 1/3 of plant protein with fish meal protein yielded an increase of 430 lb. At the 36 and 43% protein levels, 1/6 fish meal protein significantly (P<.05) increased weight gains over the all-plant protein rations; however, a further increase to 1/3 fish meal protein did not significantly increase fish yield. Under these management conditions and current feed ingredient costs, the extra yields obtained by increasing protein level and replacing plant protein with fish meal protein were profitable; particularly in the 36 or 43% protein diets in which 1/6 ofthe protein was fish meal.
