Effects of Extrusion on Nutritional Value of Diets Containing CornGluten Meal and Corn Distiller's Dried Grain for Rainbow Trout,Oncorhynchus mykiss

摘要

The effects of diet processing methods on diets containing increasing levels of a combination of corn distiller's dried grain with solubles (CDDGS) and corn gluten meal (CGM) to replace fish meal in diets of rainbow trout were investigated. A two by four factorial treatment arrangement was used with two types of diet processing methods (cold-pelleted and extruded) and four levels of corn products replacing fish meal protein (0, 25, 50, or 75%). There was an effect of processing method and level of corn products on weight gain and feed conversion ratio, and an interaction of those effects. Extrusion of diets containing the corn products did not improve fish growth compared to fish fed the cold-pelleted feed (extrusion of the wheat-containing diet did improve weight gain and feed conversion). There were interactions between process type and level of corn products on protein retention efficiency, and apparent digestibility coefficients for both dry matter and energy. The presence of indigestible carbohydrate in the CDDGS limited replacement of fish meal with the corn products to 18% of the protein.