Comparative Value of Fish Meal Alternatives as Protein Sources in Feeds for Hybrid Striped Bass

Numerous alternative proteins have been assessed and reported as adequate for fish meal (FM) sparing; however, few studies have directly compared the value of alternative proteins in side-by-side comparisons. Previous research also suggests that changes in dietary protein source may affect fillet quality, but comprehensive data on this subject are lacking. We assessed the production performance and consumer acceptance of hybrid Striped Bass (White Bass Morone chrysops x Striped Bass M. saxatilis; mean weight +/- SE = 43.4 +/- 0.2g) reared on a control diet containing menhaden FM (30% FM) as the primary protein source or on experimental feeds containing approximately 10% menhaden FM and one of the following protein sources: soybean meal (10% FM-46% SBM), poultry byproduct meal (10% FM-21% PBM), grain distillers' dried yeast (10% FM-36% GDDY), corn gluten meal (10% FM-21% CGM), or distillers' dried grains with solubles (10% FM-33% DDGS). Weight gain (1,055-1,323%), specific growth rate (SGR; 1.29-1.40% of body weight [BW]/d), and feed intake (2.10-2.28% BW/d) were equivalent among groups, except that fish receiving the 10% FM-36% GDDY feed exhibited reduced performance (weight gain = 929%; SGR= 1.23% BW/d; feed intake = 1.95% BW/d) that appeared to be related to feed palatability. Feed conversion ratio was relatively consistent among the dietary treatments, with only the highest (1.39; for 10% FM-33% DDGS) and lowest (1.16; for 10% FM-21% PBM) values being significantly different. Dietary protein source had no effect on fillet color or consumer acceptance; consumers were unable to differentiate between control and experimental portions in 64% of comparisons. Each of the alternatives used in the present study appeared, to various degrees, to be suitable alternatives to FM. The results of this and other trials suggest that the FM content in feeds for hybrid Striped Bass can be significantly reduced beyond the current standard levels without negative effects on production performance or product acceptance. Received October 19, 2012; accepted January 13, 2013