Liu Y., Tang G., Yang J., Li W. (2017): Effects of dietary conjugated linoleic acid on lipid peroxidation in breast and thigh muscles of broiler chickens. Czech J. Anim. Sci., 62, 331-338.The effect of dietary supplementation with conjugated linoleic acid (CLA) on lipid peroxidation in the breast muscles (Pectoralis major and Pectoralis minor) and thigh muscles of broiler chickens was investigated. A total of ninety-six 21-day-old Arbor Acres male broiler chickens were assigned to 2 dietary treatments (0 and 1.5% CLA) with 8 replicates per 6 chickens each. The left breast and thigh muscles of broiler chickens were excised on day 42. The broilers receiving the CLA diet exhibited lower malondialdehyde content and reactive oxygen species production (P < 0.01) in the breast and thigh muscles than the broilers receiving the control diet. After the dietary CLA supplementation, the glutathione (GSH) content in the breast and thigh muscles of the broiler chickens fed the CLA diet increased by 21.89 and 21.56%, respectively (P < 0.05) while the γ-glutamylcysteine synthetase（γ-GCS）activity increased by 28.57 and 25.80% (P < 0.05), respectively. Dietary CLA significantly increased the CLA content (P < 0.01) and saturated fatty acid content (P < 0.05), and decreased the monounsaturated fatty acid content (P < 0.01) in the breast and thigh muscles. These results showed that dietary CLA may decrease the lipid peroxidation level in the breast and thigh muscles of broiler chickens perhaps through increasing the γ-GCS activity to induce GSH synthesis and changing the fatty acid composition to increase oxidative stability.

The effects of dietary conjugated linoleic acid (CLA) on the intestinal mucosal immunity of broiler chickens were investigated. A total of 96 1-day-old Arbor Acres male broiler chickens were assigned to two dietary treatments (0 and 1% CLA) with eight replicates/each of six chickens. The intestinal mucosal immune status of broiler chickens was evaluated at 21-day old. The jejunal mucosa SIgA level increased by 43.58% (p < .01) while its mRNA expression increased by 22.95% (p < .01). The broilers receiving the CLA diet exhibited higher gene expression of jejunal peroxisome proliferator-activated receptor c (PPARc) (p < .01) while the mRNA expression level of transforming growth factor b4 (TGFb4) was not different between two dietary treatments group (p > .05). After dietary CLA supplementation, the percent of Peyer's node CD8 þ T lymphocytes increased (p < .01) and lymphocytes proliferation of Peyer's node increased (p < .05). In conclusion, the CLA diet enhanced jejunal SIgA expression, and increased lymphocyte transformation rate and the percent of CD8 þ T lymphocyte in Peyer's node of broiler chickens.ARTICLE HISTORY