Effects of Conjugated Linoleic Acid on the Pituitary-Testes Axis, Thyroid Hormones and Ram Semen Quality in Non-Reproductive Season

摘要

Conjugated Linoleic Acid (CLA) is a group of long-chain unsaturated fatty acids with >1 double bond and a mixture of 28 isomers of linoleic acid (C 18:2) and it is counted as one of the essential fatty acids. The main purpose of this study was to investigate the effect of CLA on some reproductive hormones and ram semen quality in non-reproductive season. In this study, 6 heads of 3-4 years old rams with the average weight of 90 kg were selected. Diet rams were used by NRC. Rams were randomly divided into 3 groups and were treated by CLA for 30 days. The 1st group (as a control group) did not receive CLA. The 2nd group received 0.5 g dayˉ1 and the 3rd group received 1g dayˉ1 of CLA. Consumed CLA included the c9, t11 and t10, c12 isomers. The blood testing was done on rams every 15 days (0, 15 and 30) and sperm measurements were performed every 15 days using an artificial vagina. Data analysis was performed by SAS software. Also, mean comparison was done using Duncan?s test method (p<0.05). Obtained results showed that the serum concentration of testosterone hormone was decreased numerically, as well as the concentration of FSH (Follicle-Stimulating Hormone). However, the concentration of LH (Luteinizing Hormone) was increased. Also, the CLA had a significant effect on leptin concentration. CLA in oral form can reduce the concentration of testosterone and increase sperm motility in rams. According to the obtained results in this survey, CLA is knowingly effective on reproduction. In rams, it caused an increase in dihydroxy testosterone concentrations, however it reduced the total testosterone concentration. Also, CLA caused a significant increase in total motility and progressive motility of sperms in ram.