Impact of fish meal replacement with full-fat soya on the muscle and liver fatty acid composition in rainbow trout

Abstract

The aim of the present study was to determine the impact of partial replacement of fish meal and fish oil with full-fat soya (FFS) on muscle and liver fatty acids composition in rainbow trout (Oncorhynchus mykiss). The fatty acid compositions of the rainbow trout muscle and liver were affected by the dietary treatment, and linear relationships between dietary and tissue FA concentrations were observed for some of these. The liver of fish fed with the fish meal and fish oil diet had significantly higher levels of 16:0, 20:5n-3, n-3 polyunsaturated fatty acid than those of fish fed with the full-fat soya diets, whereas increases in 18:1n-9, 18:2n-6, n-6 polyun-saturated fatty acid and polyunsaturated fatty acid /saturated fatty acid were observed in the liver of fish fed the FFS diets. The present results showed that the replacement of fish meal and fish oil with full-fat soya caused significant reductions in the muscle eicosapentaenoic acid, docosahexaenoic acid and n-3/n-6 polyunsaturated fatty acid ratio, and consequently reduced availability of these essential n-3 polyunsaturated fatty acid to consumers.