Effect of dietary lipids on fatty acid composition and lipid peroxidation in sarcoplasmic reticulum of hybrid tilapia, Oreochromis niloticus×O. aureus

Abstract

The effects of dietary lipid sources on the growth response of hybrid tilapia ( Oreochromis niloticus× O. aureus) were investigated. Enzymic lipid peroxidation in the sarcoplasmic reticulum (SR) of these fish fed different dietary lipids was also studied. Experimental fish were given diets containing no additional lipids (control), lard, soybean oil, menhaden fish oil and methyl esters of n-3 highly unsaturated fatty acids (HUFA) for 10 weeks. There was no difference in survival rates among test groups. Compared to fish supplied with dietary lipids, fish consumed control diet with trace lipids (0.02%) were low in final body weights and muscle lipids. The specific growth rates and weight gains of fish fed soybean oil and fish oil were significantly higher than other groups ( P<0.05). Fatty acid compositions of muscle and SR reflected the fatty acid compositions of dietary lipids. The thiobarbituric acid reactive substances produced by iron catalyzed NADH-dependent lipid peroxidation were significantly different ( P<0.05) among SR isolated from fish fed different dietary lipids. Lipid peroxidation activity of HUFA group was the highest, followed by fish oil, soybean oil, lard and control group.