The Effect of Dietary Protein Level on Channel Catfish Production Characteristics when Feeding on Alternate Days in Multiple-Batch Production

Abstract

Pond studies were conducted in 2002 and 2003 to determine whether reduced growth from feeding channel catfish Ictalurus punctatus every other day in multiple-batch systems could be overcome by offering feeds with a higher crude protein level. In the 2002 study, fish were fed a commercial diet containing either 28% or 36% crude protein every other day to apparent satiation. Survival, net yield, total yield, and weight at harvest of either fingerlings or carryover fish (second year of production; mean weight, 300 g) fed a 28% crude protein diet were not significantly different from those of fish fed the 36% crude protein diet. Fingerling growth was less than 1.0 g/d for both diets, while carryover fish reached market size with both diets when fed every other day. The study was expanded in 2003 to include a 32% protein treatment and control (fed daily). Fingerling growth, weight at harvest, and feed conversion ratio (FCR) were significantly lower when fingerlings were fed every other day than when the fish were fed daily. Higher protein levels did not improve survival, FCR, growth, weight at harvest, or net yield of fingerlings. Carryover fish in all treatments reached market size by the end of the study, but yield was lower when fish were fed every other day and was not affected by protein level. Partial budget analysis indicated a positive change in revenue the first year from switching from feeding every day to feeding every other day, but returns turned negative during the second year. Feeding every other day resulted in smaller fish, lower carryover biomass, and second-year yields below the break-even level. No evidence was found to support the use of higher-protein diets when feeding every other day.