Effects of Commercial Fish Meal Analogue and Menhaden Fish Meal on Growth of Red Drum Fed Isonitrogenous Diets

Four diets were formulated to determine the effectiveness of supplementing a commercially available protein source (Pro-Pak® from H. J. Baker and Brothers, Inc.) for menhaden fish protein (Special Select® from Zapata Haynie Corp.), in diets for red drum Sciaenops ocellatus. The diets were formulated to be isonitrogenous, each contained 45% total protein. Protein from soybean meal and wheat gluten was kept constant; Pro-Pak replaced 0, 25, 50, or 75% of the menhaden fish meal on an equal protein basis. In the first 8-week growth trial, which used satiation feeding, positive results from high fish meal diets were observed; percent weight gain ranged from 630 to 830%, and there was near 100% survival. In a basal diet containing 40% fish meal, the replacement of 50% of the fish protein with Pro-Pak resulted in minimal changes in growth and feed consumption. The replacement of 75% of the fish protein in the basal diet (diet 4) resulted in reduced performance of the fish. The second growth trial confirmed reduced growth rates of fish fed diet 4 under fixed feeding conditions, confirming nutritional differences between the test ingredients. Based on the results of this study, with appropriate restrictions, Pro-Pak should be considered an acceptable ingredient in practical diets for red drum.