Surgical and non-surgical transfer of bovine embryos

Methods of transferring one bovine embryo to the ipsilateral uterine horn have been compared. In heifers mid-ventral surgical laparotomy under general anaesthesia (n=22) was compared with flank surgery with paravertebral anaesthesia (n=21). Pregnancy rate was higher with a midventral approach (P less than 0.05) (77.3 per cent of 42.9 per cent respectively). In heifers mid-ventral surgery (n=36) was compared with two methods of non-surgical transfer either using the Cassou insemination gun (n=36) or a modification of it (n=39) with embryos collected on days 7, 8 or 10 after oestrus. There were no differences in pregnancy rate between methods or different ages of embryos (methods: 55.6, 55.6, 43.6 per cent respectively; Day: 48.8, 55.8, 48.1 per cent respectively) but the condition score of recipients affected success (P less than 0.05). Of 10 cows which each received an embryo using the modified Cassou gun eight became pregnant.