Effect of certain fatty acids on the fertilizing capacity of frozen ram semen

Abstract

The objective of this study was to determine the effect of alpha linolenic acid, linoleic acid, conjugated linoleic acid isomer (cis-9; trans-11) and arachidic acid on the cytological parameters (sperm progressive motility, alive sperm percentage, functional membrane integrity, percentage of intact acrosome and total abnormalities), biochemical parameters (aspartate aminotransferase, alkaline phosphatase, superoxide dismutase, glutathione peroxidase enzyme and malondialdehyde) and fertilizing capacity (in vitro fertilization and culture of ewe oocytes) of frozen-thawed ram semen. Five mature fat-tailed rams were used in this study. Semen was collected once weekly. Collected semen was transferred to the water bath at 37 oC. The semen samples were pooled and divided into 13 aliquots, each aliquot was diluted using different diluents. Egg yok-Tris diluents containing alpha linoleic acid (50, 100 and 150 µM), linoleic acid (50, 100 and 150 µM), conjugated linoleic acid (50, 100 and 150 µM) and arachidic acid (5, 10 and 20 ng/ml). The diluted semen containing fatty acids was cooled to 5 oC and processed into 0.5 ml straws. The best results based on the protection of semen characteristics and fertilizing potential of ewe oocytes were obtained from alpha linolenic acid (50 µM), conjugated linoleic acid (150 µM) and arachidic acid (10 ng/ml). No significant effect was noticed by addition of linoleic acid to freezing media on fertilizing potential.