A Dead Cert : Experiment 9
9. Mares given drug to improve outcome of pregnancy by embryo transfer – and then deliberately aborted
Equine Fertility Unit, Cambridge
Researchers in Cambridge studied the effect of a prostaglandin-inhibiting drug on the pregnancy rate of mares made pregnant through embryo transfer.
Prostaglandins are hormone-like substances that stimulate heat cycles. A total of 72 recipient mares – half of whom were given the experimental drug – each had one embryo flushed into her womb. All of the animals used in this study (i.e. donor and recipient mares) were young, healthy, fertile mares who had been resident at the Equine Fertility Unit for more than a year.
Blood samples were taken from all the recipient animals on a regular basis throughout the entire experiment. Two weeks after the embryo transfer, pregnancy was confirmed using ultrasound. At this point, all of the pregnancies were deliberately terminated by the administration of an aborting drug, with the exception of four mares, who were aborted 10-14 days later.
Comment: While embryo transfer and similar artificial reproductive methods are currently not allowed for race horses, one of the authors (WR Allen) is an outspoken advocate for the ban to be lifted.
Wilsher S, Kolling M, Allen WR. Equine Veterinary Journal, 2006; 38(5): 428-432. Meclofenamic acid extends donor- recipient asynchrony in equine embryo transfer.