I MEET with Dr John Haughey on a wild January day in South Armagh and already, the breeding season has begun.

Now into the third year of running his new clinic, John has successfully put healthy foals on the ground for some of Ireland’s best-known equestrians using both embryo transfer (ET) and artificial insemination (AI).

The Carrickview Stud yard is non-stop, and John finds time to chat to me, not over tea, but while scanning a stunning former Longines Global Champions mare who will soon be going for intracytoplasmic sperm injection treatment (ICSI).

“There has been a massive increase in clients requesting embryo transfer,” John tells me.

“ET allows foals to be born from mares with subfertility or uterine pathology or older mares. The main benefit is the ability to produce foals from competition mares and allowing their genetics into specific breeding programmes. In the past, quite often these genetic lines were lost as successful mares were so often sold on. ET can also allow high genetic mares to produce more than one foal in a season and it also allows mares who can’t carry a foal for medical reasons to produce offspring.”

Affordable

With the rise in popularity of ET and its affordability increasing, it’s easy to forget what a complex and delicate veterinary procedure it actually is, with pregnancy rates varying from 70%-90%.

John explains: “From the initial request, I advise the client to find two recipient mares. The donor mare and the two recipients are scanned to establish at what stage of cycling they are, and then a plan is made to synchronise all three mares, with the aim of the donor ovulating just before the recipients. I will only use a recipient that has ovulated on the same day or up to five days after the donor. Once the donor has been artificially inseminated with the chosen semen, the donor mare is flushed.”

The flushing of a mare for embryo collection is a delicate procedure, done with a transcervical uterine lavage which involves fluids ‘flushing’ the embryo out of the mare’s uterus and through a filter system which catches the embryo, or in the case of twins, embryos. John details: “If we retrieve an embryo or embryos, we check both recipients and determine which looks more suitable, and the embryo is then implanted into that recipient or in two recipients for twins. The recipient will then return to her own environment and be checked after seven or eight days for pregnancy. When the donor is flushed, we inject her with prostaglandin (PG) to ensure no embryo is left inside. The mare will come back into season in a couple of days, and if desired, the process can begin again.”

With an upsurge in ET, there has also become a greater need for recipient mares. Still, not just any mare is suitable as a recipient, and John is very clear in his view that owners must provide healthy mares for successful pregnancies via embryo transfer.

“All recipient mares will be scanned for breeding soundness before we consider using them. In terms of outward health, in my opinion, a recipient should be a good solid mare, with good body condition and be three to 10 years old. Maiden mares are desirable as they are clean without any internal infection; however, I will also consider mares who have foaled before, as long as they have good reproductive health. Good recipient mares can vary, but in general, I prefer a cob over 15.2hh or a sports mare over 16hh. There must be no previous history of reproductive problems; a mannerly mare is always a plus and mares must be wormed and vaccinated.”

Monitor

Once the embryo transfer is made, the complexities don’t cease, and the pregnancy must be very carefully monitored in the following weeks. John reiterates: “Like everything, lots can go wrong: sometimes the embryos retrieved can be weak. However, I believe that if you have an embryo, no matter what grade or shape it is, you should transfer it. Nature is powerful, and there is always a chance of a healthy pregnancy. A recipient’s failure to hold the embryo can be another problem, and not always one we have an answer for. If a recipient does not hold an embryo following a flush that has gone well and a good healthy embryo has been retrieved, I tend not to use that particular recipient mare a second time. In any pregnancy, you can lose a foal at any time, but generally, if it gets to 60 days, the foal will make it to full term.”

Influence

When I question John on the notion that a recipient mare can influence the resulting foal, he responds: “Lots of research is being done on the impact of the recipient on the resulting foal from ET, and I think it’s pretty much determined by the donor, although minor influences on some physical traits such as height and birth weight have been attributed to the recipient. Generally speaking, and according to the research to date, the recipient does not appear to impact the athletic ability of the foal or resulting adult athlete animal.”

ICSI is slowly following in the footsteps of ET in terms of availability in Ireland, but the cost is currently prohibitive for many owners. There is minimal access to the procedure here, and most clients go abroad to seek the method.

When I question John about the use of ICSI, he explains: “I am undergoing ICSI training myself, and hopefully we will offer this service at Carrickview Stud in the not too distant future. ICSI differs from ET as the entire fertilisation process is done physically by the veterinarian. A single sperm cell is injected directly into a mature oocyte (egg), and the embryo is then grown in an incubator – the resulting embryo can then either be transferred or frozen. ICSI is becoming quite mainstream, and I believe it will go from strength to strength within the industry here.”

Gene pool

Some believe that ET and ICSI have a negative impact upon breeding in terms of promoting a restricted gene pool, I ask John how he feels about this as both a veterinarian and as a breeder himself.

“Ultimately, it’s difficult to determine its influence as a positive or negative just yet. I think these procedures are certainly useful in competition mares who cannot stop their career to foal down. It can also be helpful for older mares who have been prolific producers: many mares that produce top progeny are often in their teens before it is determined how good they are. ICSI is also an important tool for using semen of which supply is restricted (deceased stallions) or of poor quality. But ET for ET sake and ICSI for ICSI sake is not a positive move for any breed. Long-term it will stop exclusivity of dam-lines and lead to a palpable restriction on our gene pool. While on the one hand, I do think it’s great to use both methods in specific cases; I believe there should be some policing on how much can be done because we must consider our mares’ welfare at all times and the greater breeding picture too.”