INFLUENCE OF EQUILIBRATION TIME DURING VITRIFICATION AND CULTURE MEDIUM ON DEVELOPMENT OF IN VITRO-DERIVED BOVINE EMBRYOS

Abstract

The objective of the present study was to examine the influence of culture mediumand equilibration time during vitrification on development of cryopreserved in vitro-derived bovine embryos. Following insemination, 50% cumulus-enclosed presumptive zygotes were designated as controls and returned to the original microdrops for further incubation and theremaining of the embryos microdrops, randomly assigned into two culture groups, TCM-199 containing 10% (v/v) fetal bovine serum and SOM prepared with the elevated potassium formulation (KSOM) supplemented with 1%BSA were vitrified. Embryos were recovered from the cryo-vials and warmed at 37oC in 0.3 M trehalose in TCM-199 for 1-2 min. Each group of embryos was immediately washed 3 times with its respective culture medium, KSOM or TCM, and returned to their corresponding microdrops containing the cumulus cell complement. Embryos were cultured for an additional seven days and evaluated at 24-h intervals to assess development. Development of presumptive bovine zygotes was similar in KSOM and TCM prior to vitrification. Development of bovine embryos was significantly greater (P0.10) percentages to control and both were greater (P