Quality of Bovine Chilled or Frozen-Thawed Semen after Addition of Omega-3 Fatty Acids Supplementation to Extender

Background: This study was conducted to evaluate the potential protective effects of omega-3 poly unsaturated fatty acids (?-3 PUFAs) on bovine sperm quality in response to cooling and cryopreservation. Materials and Methods: In this experimental study included ejaculates from five proven fertile bulls, allocated to the control and the four experimental groups. For group 1, polyethylene glycol (PEG) as a solvent was added alone to the extender, while for groups 2, 3 and 4, different concentration of omega-3 PUFAs (1, 2.5 and 5%, respectively) in combination with PEG were added to the semen extender. Motility [using computer aided sperm analysis (CASA)], viability and morphology of bovine sperm were investigated after 24 and 48 hours in both cold liquid storage and frozen-thawed conditions. Results: Our findings showed that PEG has some detrimental effects on sperm quality. Cooling as well as cryopreservation decreased significantly most of measured variables of sperm as compared to fresh semen, whereas the treatments did not improve sperm quality. Furthermore, levels of some variables were decreased significantly during treatments (p < 0.05). Conclusion: Addition of ?-3 PUFAs to semen extenders cannot be effectively introduced to conservation media as well as sperm membrane in order to protect spermatozoa in response to cooling and freezing. It can be suggested if ?-3 PUFAs is supplemented to the diet of bulls in order to modify the fatty acid compositions of sperm, they might perform their preventive properties.