Egg transplant attempt

Press, Volume CXII, Issue 33094, 8 December 1972, Page 10

Egg transplant attempt

What may be a New Zealand veterinary “first” took place last week at Sir John Ormond’s Wallingford station in central Hawke’s Bay, according to the New Zealand Press Association. Waipukurau veterinarians carried out the first stages of a multiple fertilised ova (egg) transplant on a 13701 b Angus cow.

While the operation was not a complete success — the cow had not reacted to a hormone injection to boost its ova production before insemination — it is regarded as a rehearsal of equipment and anaesthesia techniques for another attempt scheduled for about two weeks time. Mr Russell Dreadon, of Waipukurau, one of the veterinarians, said the multiple fertilised ova transplant was the brainchild of Cambridge University in England. Through its use a single cow could produce fertilised ova a maximum of eight times a year, with the ova developing in the wombs of foster mother cows. Mr Dreadon said the donor cow was given a hormone injection before coming into season to produce a large number of ova. The cow was then artificially inseminated and, six days later, the fertilised ova were removed from it

to be transferred to the wombs of “foster mother” cows. In the early days of the operation, the fertilised eggs were taken from the cow’s fallopian tubes, before entering the uterus. Research showed, Mr Dreadon said, that this had a detrimental effect on the donor’s fertility. In last week’s operation the eggs were flushed from the uterus. However, because of the apparent failure of the hormone injection, there was not the expected number of eggs. “The next time we perform it, we will manage it in a fraction of the time — this operation has brought us much closer to making the next one a sucMr Dreadon said. Local veterinarians said this week that the Waipukurau veterinarians were to be congratulated on their enterprise and there was no

doubt that with greater experience of the technique they would be as successful as anywhere else. It was, however, pointed out that the operation involving the removal of the eggs from the donor cow was likely to be an expensive one that should desirably be carried out under good conditions and was not one that would probably be carried out on a farm. A problem with the technique was in having foster cows in a receptive state to take the eggs. There were still problems involved in synchronising cows and even when this was done in the first heat period fertility was disappointing. However, there had been some success with deep freezing fertilised eggs, which might then be held for use with cows at the appropriate time. The technique did offer the opportunity of increasing the number of progeny that could be obtained from a cow of outstanding genetic merit, and it also offered a means of increasing numbers of progeny of an exotic breed. It was a technique that would no doubt be used to increase numbers of exotic sheep breeds, as in this case there was no problem in synchronising ewes to act as foster mothers for eggs from the donor ewe.