Six experimental catfish feeds, containing 29, 36, and 42% crude protein at metabolizable energy (ME) levels of 1000 and 1300 kcal per Ib, were fed to fingerling channel catfish in 24, 1/ I0-acre earthen ponds for 165 days. Each dietary treatment was randomly assigned to four ponds which were stocked at a rate of 4,000 fish per acre. Feed allowance was increased biweekly on the basis of fish weight gain until a maximum daily allowance of 40 Ib per acre was reached. The higher energy plane resulted in greater weight gains, more fish protein produced per acre, and slightly fatter fish, at each dietary protein level. At the lower ME level the difference in growth among fish fed the 29, 36, and 42% protein diets was not significant (PV.05). At the higher ME level the fish showed increased gains with each increase in diet protein percentage. The high protein (42%) - low energy (1000 kcal) diet produced the lowest gain of the six treatments, indicating that high levels of protein may be toxic to catfish with low amounts of nonprotein energy.
