Culture and Transfer of Calf Ova

Modified I-Iam's F10 and TCM 199, each with 1.5% bovine serum albumin, were used to culture superovulated ova from pre-and postpuberal heifers. The maximum cleavage in vitro was from the 1-cell to the 12-cell stage. Twenty-two of 30 normal appearing 2-cell ova recovered from calves cleaved further when cultured in chemically defined media, but five calf ova with four or more blastomeres at the time of collection and ova collected 5 days after ovulation did not cleave further in vitro. This suggests that the reproductive tract of the immature animM may be harmful to ova. Four of 14 calf ova cleaved up to three times in the ligated oviduct of pseudopregnant rabbits.