Effects of different diets on fatty acid composition and nutritional values of largemouth bass ( Micropterus salmoides )

Abstract

This study investigated the effects of different diets (formulated feed, frozen trash fish and conversion of two diets) on fatty acid composition of largemouth bass Micropterus salmoides. A total of 184 food-size individuals were collected from 21 commercial largemouth bass ponds. In all samples, thirty-two fatty acids were detected, and five fatty acids (C14:0, C16:0, C18:1n9c, C18:2n6c, C20:5n3 and C22:6n3) were major, which accounted for 75% of the total fatty acid content. There was a positive correlation between the fatty acid composition in diets and fillet. Significant differences were detected in the fatty acid composition of largemouth bass between frozen trash fish group and formulated feed group. Statistical analyses revealed that 17 fatty acids, including DHA (Docosahexaenoic Acid), were highly significantly different between three diet groups (p < 0.01). The levels of ω-3 PUFAs (Polyunsaturated fatty acid), ω-6/ω-3 PUFAs ratio, and S: M: P ratios of frozen trash fish group were significantly higher than formulated feed group. These results could provide theoretical basis for the transformation and upgrading of diets for largemouth bass and have important significance for promoting healthy and sustainable aquaculture methods.