Effect of transportation in vapour nitrogen on viability of bovine oocyte

Transporting vitrified oocytes using nitrogen vapour shipment between different places at a long distance is a common practice. However, achieving high viability of bovine oocytes during vapour shipping is a technique that has not been fully studied yet. In this study, the objectives were 1) to determine the efficacy of vitrification and 2) to access the viability of bovine oocytes after vapour nitrogen transportation. Retrieved bovine oocytes (n = 55) from slaughterhouse derived ovaries underwent in vitro maturation for 24 hours prior to vitrification using slightly modified semen straw. The viability of post-warmed bovine oocytes were evaluated after mimicked transportation with liquid and vapour nitrogen on a shaker with 300 rpm for one hour, for treatment group 1, n = 17 and 2, n = 9, respectively. Vitrified bovine oocytes, without transportation were used as control (n = 20). The result showed that post-warmed bovine oocytes in vapour phase nitrogen maintained excellent viability after one hour mimicked transportation, where 91% appeared intact morphology with FDA staining bovine oocytes. There was no significant difference (p = 0.465) of treatment groups with those vitrified control group, which both treatment groups achieved 100% of viability while the control group was 90% of viability. In conclusion, vapour nitrogen transportation proved to be an effective, safer and cheaper method of transporting reproductive cells without adverse effect on the viability of post-warmed oocytes. Thus, vapour nitrogen transportation is recommended in transporting reproductive cells because it is convenient for long distances without compromising the oocytes viability.