In an 8-week trial, 300-g channel catfish (Ictalurus punctatus) were fed at five feeding rates: a control group which was fed at a rate that approximated the ad libitum rate for this size fish, and four groups which were fed at 110, 90, 75 and 50% of the control rate. Significant decreases in growth and feed conversion (feed/gain) rates were obtained in treatments fed 110% of the control rate. Water quality monitoring indicated that this reduction in performance was not due to poorer water quality. Gains were not significantly affected by feeding 90% of the control level, but were reduced in the 75 and 50% treatments. Food efficiencies were improved by reduction of the feeding rate to 90 and 75% of the control level, but were not further improved at the 50% feeding level. Total absorbability and digestible energy values for the test diet were improved by restricting the rate to 90% of the control, but protein absorbability was not affected. © 1979.