The effects of dietary conjugated linoleic acid (CLA) on fatty acid composition and key enzymes of fatty acid oxidation in liver and muscle of geese

Abstract

The objective of this study was to determine the influence of conjugated linoleic acid (CLA) on fatty acid composition and key enzymes of fatty acid oxidation in liver and muscle of geese. A total of 192 1-day-old geese were randomly assigned to 1 of 4 dietary groups, and were fed for 56 days on diets containing 2.5% soybean oil (group A, control group) or 2.0% soybean oil with 0.5% CLA (group B), 1.0% soybean oil with 1.5% CLA (group C), and 2.5 % CLA (group D). Geese fed CLA had a decreased abdominal fat percentage (AFP) (P < 0.01) compared with the control. It was observed that dietary CLA levels had a significant effect on the body weight, weight gain, feed conversion rate (FCR) (P < 0.05), and feed intake (P < 0.01). Fatty acid composition showed a significant increase of the biologically active cis-9, trans-11 and trans-10, and cis-12 CLA isomers in both liver and muscle of geese fed CLA (P < 0.01). Dietary CLA led to an increase (P < 0.01) in saturated fatty acid (SFA) and a reduction in monounsaturated fatty acid (MUFA) (P < 0.05) concentrations in both liver and muscle. In liver, dietary CLA increased (P < 0.05) acyl CoA oxidase (ACO) activity, but did not affect carnitine palmitoyltransferase-I (CPT-I) activity compared with the control. CPT-I activity was significantly increased by 2.5% dietary CLA in muscle, where ACO activity was decreased at 1.5% CLA level. The results obtained suggested that geese can successfully incorporate CLA in both liver and muscle, which could be beneficial in the human diet, through provision of bioactive fatty acids with no detrimental effects on n-3 PUFA levels.