Effects of Dietary Supplementation of Conjugated Linoleic Acid on Pro- and Anti-Inflammatory Cytokines Gene Expression in Uterus of Holstein Dairy Cows

After parturition, inflammation of the reproductive tract in cows is common because of bacterial contamination of the uterine lumen. To investigate the beneficial effects of dietary Conjugated Linoleic Acid (CLA) supplementation on health status mediated by change in pro- and anti-inflammatory cytokine genes expression, endometrial samples were collected from Holstein cows with similar parturition date and reproductive records. From day 21 before calving to day 42 after calving, cows were fed isonitrogenous, isocaloric, and isolipidic diets that differed only in the source of fats. Cows were fed diets supplemented with palm oil as control group (saturated FA; n= 8), and CLA for the treatments, and the rate of each fat in any diet was 75 g d-1</sup>. CLA-supplemented diet was provided with a mixture of trans</em>-10, cis</em>-12 CLA and cis</em>-9, trans</em>-11 CLA isomer. Rumen protected CLA provided 10 g d-1 </sup>each of trans</em>-10, cis</em>-12 CLA and cis</em>-9, trans</em>-11 CLA isomers. Uterine endometrial biopsies were collected at days 21 and 42 after calving and were prepared to determine pro-inflammatory [including Tumor Necrosis Factor-α (TNFα), InterLeukins (IL-1, IL-6, IL-8) and InterFeron-gamma (IFN-γ)] and anti-inflammatory [interleukin 10 (IL-10)] cytokine genes expression. Results showed that dietary CLA supplementation decreased the expression of IL-1 and IL-8 at days 21 (respectively, 1.8 and 3.9 fold) and 42 (respectively, 4 and 104 fold) postpartum and increased expression of IL-10 at days 21 and 42 (respectively, 9.7 and 2.5 fold). The TNFα expression significantly decreased in day 21 in CLA groups compared with palm (2.5 fold). There was no difference between groups for IL-6 expression. IFN-γ expression decreased in day 21 (3.0 fold) and, conversely, increased in day 42 (2.5 fold) in CLA group compared to palm. Our results showed that, during transition period, dietary supplementation with CLA reduced inflammatory processes via inhibiting pro-inflammatory cytokines and stimulating anti-inflammatory cytokines.