Survivability of caprine oocytes vitrifed in conventional and open pulled straws

Abstract

The aim of this study was to compare the efficacy of conventional straw vitrifcation with open pulled straw vitrifcation interms of cryosurvivability and damages caused to the oocytes. Two hundred immature goat cumulus oocyte complexes (COCs) werevitrifed in a solution of ethylene glycol, dimethyl sulfoxide, and sucrose using either conventional straws (100 COCs) or open pulledstraws (100 COCs). Te COCs were warmed and observed for morphological damages and viability afer 7 days of preservation inliquid nitrogen. Among the 100 COCs cryopreserved in each case, only 83 COCs were recovered afer warming in conventional strawvitrifcation as compared to 94 COCs in open pulled straw vitrifcation. In terms of morphological survivability, the percentage ofmorphologically normal oocytes was greater (P < 0.01) in the case of open pulled straw vitrifcation (86.2%) as compared to conventionalstraw vitrifcation (59.0%). Viability percentage of live oocytes was greater (P < 0.01) in the case of open pulled straw vitrifcation(90.4%) as compared to conventional straw vitrifcation (66.3%). Te results indicate that open pulled straw vitrifcation is better thanconventional straw vitrifcation for rapid freezing of immature goat COCs in terms of both morphological survival and viability.