Abstract
Bovine embryos recovered 7-8 days after estrus were stored for 6-7 h at room temperature in BMOC-3 or Ringer's solution supplemented with 50% bovine serum which had been collected from superovulated heifers 7 to 8 days after estrus.
Single embryo was transferred to the uterine horn ipsilateral to the corpus luteum-bearing ovary 7-8 days after estrus using Cassou apparatus with 0.25 ml French straw. To prevent bacterial con-tamination, the Cassou gun was covered with a sterile plastic tube which was not punctured until the cervix was catched.
Pregnancy rate was not different between embryos kept in Ringer's solution supplemented with 50% bovine serum (8/14, 57.1%) and those kept in BMOC-3 (6/10, 60%).
Another group of bovine embryos were cultured at 37 C for 72 h in a stoppered test tube contain-ing 1 ml medium and air. Five embryos were cultured with Dulbecco's PBS plus 20% bovine serum and two embryos with Dulbecco's PBS plus 20% ovine serum (GIBCO). After 24 h of culture, all em-bryos were developed into expanding blastocysts. After 48-72 h, all embryos cultured with Dulbecco's PBS plus 20% bovine serum hatched from zona pellucida, and they did not degenerate after this time.
Whereas two embryos cultured with Dulbecco's PBS plus ovine serum degenerated after 48 h of culture.
These results suggest that supplementation of the serum of the same species is beneficial for the survival of the embryos cultured in vitro.
