Skip to main content

Town and Country Vet Equine A I Programme

By Bill Moore

In a converted old stables at the top of a long driveway in the Richmond foothills some delicate work is going on that is pumping new life into the South Island’s horse stock.

The Town and Country Vet Equine, operated by Town and Country Vet Richmond, is producing foals fathered by stallions not only from around New Zealand and Australia, but now from anywhere in the world, where owners find the bloodlines they want.

The breeding season is in full swing and this year mares at the Paton Road clinic are being impregnated by stallions from Germany, the United States and Britain.

In the thoroughbred racing world, it has to be done the old-fashioned way, with mares shipped to stand with stallions at stud. For other horse types, including the standardbreds who trot and pace ahead of sulkies, artificial insemination (AI) has caught on. It’s getting more and more popular as success rates rise and the cost falls.

Town and Country Vet Equine veterinarian Roger Bay says the 80-hectare property is ideal for the job, because mares can be kept there until they are ready for insemination – the timing is crucial – and afterwards.

Fresh semen is sourced from around New Zealand and Australia, flown in chilled containers. The breakthrough has come with the use of frozen semen. This can be brought in from around the world.

AI for horses has been around for two decades, but the frozen variety did not really catch on until the technology advanced.

The freezing process is very harmful to the semen, Dr Bay says. “You get a lot of attrition.”

Once it has been defrosted and put inside a mare, the success rate has climbed from the 30 to 40 per cent to the 60 to 70 per cent range.

“A lot of that is to do with the technology of freezing semen well and defrosting it in the right procedure, but also understanding a mare’s ovulation pattern and making sure that semen is imported ideally just after she’s ovulated so that you can get semen in there. The best time is within six hours of ovulation.”

So the mares are faced – rear-ended, to be more accurate – with a series of ultrasound scans.

“We might have to do it multiple times through the day and through the evening. We’ve been artificially inseminating mares late at night and in the early hours of the morning to time that.”

When the moment arrives, a pipette is used to deposit the semen into the uterus. Fourteen days later, pregnancy can be determined. This is also when twins can be detected, which means that one can be terminated, avoiding the high possibility of spontaneous abortion later.

At 28 days detection of a heartbeat confirms the foetus is growing healthily and then comes the 42-day scan which tells the practice that the mare can safely go.

That’s also when the stud that the semen came from is notified, because the contract is often based around live foal guarantees.

Often, they remain until the 42- day mark that indicates a safe pregnancy is achieved. Sometimes they are there longer.

While fresh chilled semen survives for days, the frozen article can be held for years, but while there’s enough for three inseminations, the buyer can only use it for one pregnancy. Standardbred stud fees can be $10,000. Fees are lower for other types of horse – $2000 to $4000 – and frozen imports are now competitive with fresh semen, boosting their popularity.

Dr Bay explains much of this while quietly scanning a pregnant mare who stands patiently in the purpose-built crush, an essential part of the setup.

This mare, inseminated with semen from a Wellington region stallion with German bloodlines, is calm and co-operative, while her insides are probed and inspected. The most she does is shift from foot to foot. They are not all like that.

“There have been some serious injuries to vets and personnel around the issue of working around the back end of horses,” Dr Bay says. “They can lash back with ferocity.”

Three years ago, a highly experienced North Island equine vet was rendered comatose and permanently disabled after a mare got her back legs over a gate and kicked him in the head.

“These days, leaning over a gate or standing behind a hay bale – you can’t defend that in terms of what safety and health requirements are, so we’ve invested in a solid strong crush based on some of the breeding centres in the North Island.”

A mare might be at the centre for up to four months if an initial pregnancy is lost and the process has to start again. Pregnancies average 340 days, but can go for longer than a year.

Human mothers will be impressed or horrified to learn that mares can conceive again eight days after giving birth.

“The older they get, the more difficult they are to breed; the younger the more fertile,” Dr Bay says. “A lot of mares are straight back in. A breeding mare will go through into her 20s, but their fertility falls off after about 15 or 16.

“But we get a lot of mares who have been worked, eventing, racing or whatever, then people want later in life to breed.

“When they come in in the mid-teens or late-teens bracket, they can require quite a bit more skill and care to get them through.”

Dr Bay says the practice has benefited from the knowledge of Dr Jeff Grimmett, who trained overseas in equine reproduction. The only registered specialist in the South Island and one of only four in the country, he has been a “hands-on mentor and tutor” to the other vets in the practice.

Fresh semen from New Zealand or Australia can usually be organised for a mare on heat within a couple of days.

Dr Bay says a good stallion’s semen can last for five days. “It’s chilled down to 3 to 5 degrees, then warmed back up and off they go.”

The process for frozen semen is longer and more complicated, taking between two and four weeks to import it and get it through quarantine.

That has not stopped it becoming about 15 per cent of the AI business.

One enthusiast is the clinic’s leading stablehand, Laurie Arnold. A qualified vet nurse, she is a keen horse breeder, trainer and eventer and has just paid for her hanoverian mare Gem to be inseminated with semen from a young hanoverian stallion in Germany.

“She’s only three. She’s already been to the show and she got champion,” Ms Arnold says. “The stallion is a hanoverian as well, a show-jumping horse. He’s a young horse too. She’s due for a scan this week, so fingers crossed.

“Using frozen, you can get the best bloodlines in the world, where you wouldn’t be able to otherwise.”

Dr Bay says it’s hard to estimate the size of the Nelson region’s horse population.

“There are horses everywhere, tucked up in paddocks and up valleys.”

But it is very diverse, including a “solid, small and committed” standardbred scene, western horses, showjumpers, dressage horses, ponies, and “right down to the little tiny miniatures”.

All are candidates for AI, except the miniature horses, and there’s a simple reason for that.

Ponies can be artificially inseminated by women vets, with their smaller hands, Dr Bay says.

“But the miniatures are not suitable for AI – they’re just too small to get your hands in.”

For them, thoroughbreds and some other horses who don’t take to AI, it’s still done the old-fashioned way, and purists will be pleased to know that there are still, as Dr Bay puts it, “a few stallions standing in Nelson”.

The clinic is also used for in-patient surgeries, lameness clinics and dental clinics.

Although the focus is on horses, they aren’t the only visitors. The more unusual include alpacas, llamas, bulls, cows, pigs, sheep, goats and the occasional yak.