July 2017

A top equine reproduction expert in Cambridge

Dr Lee Morris is a highly respected specialist in equine reproduction. Lee grew up in the Hunter Valley in NSW near a town called Scone, which is regarded as the horse capital of Australia.   Thanks to the local vet who used to take her to farms with him from the age of 6, she was very interested in animals despite growing up in town.

Lee graduated from the University of Sydney in 1992 with a Bachelor of Veterinary Science. After two years in rural veterinary practice in northern NSW, she did a three-year residency programme in Theriogenology at the University of Guelph in Canada. She graduated with a Doctorate of Veterinary Science in 1998.  Her thesis studied male infertility.

Theriogenology is the study of reproduction of “beasts” and is a specialised branch of veterinary medicine. Theriogenologists are veterinarians with advanced training in animal reproduction and obstetrics.

Lee is an Honorary Lecturer at the University of Waikato. She’s worked in the Equine Fertility Unit in the UK and was the Senior Registrar in Equine Reproduction at the University of Sydney. She has been in New Zealand since 2002 and is now the Specialist Equine Reproduction veterinarian at EquiBreed NZ Ltd, although her skills are sought after around the world. She has presented her research internationally and published more than 30 peer reviewed scientific papers.

Lee says the fertility of New Zealand horses is not particularly high. She says first cycle conception rate in the thoroughbred industry in New Zealand is only 53% per cycle whereas the perception is that breeders should be getting close to 100% conception using natural mating.

A lot of Lee’s work has been about understanding why mares don’t conceive when they’re first served. She says in other countries the conception rate is more like 60-65% percent.

One challenge is the old population of mares in New Zealand. Lee says that past 14 years of age a mare’s fertility drops but there is little culling taking place in New Zealand. Superimposed on this challenge is the short breeding season for thoroughbreds aimed to optimise the price of yearlings.

Another issue in fertility is the different types of semen. Using frozen semen from overseas is always a bit risky as quite often the sperm numbers are low, which isn’t obvious unless the samples are checked by a lab.

To cover those issues, Equibreed use a range of techniques to try and optimise a successful AI – from managing semen and checking out the best performing sperm, managing and monitoring the mare in the lead up to insemination, and deep uterine insemination techniques to make sure the sperm get the best chance of success by giving them a good start up the reproductive tract.

The Equibreed business is based in Lee’s home farm near Cambridge. She says having the centre at home offers good work/life balance.

Reproductive services include semen collection from stallions and preparing it for either immediate artificial insemination (AI ) or shipping it to other parts of New Zealand, or freezing for use at another date.

Lee’s special interests include artificial insemination (AI), embryo transfer (ET), epididymal spermatozoa, hysteroscopy, equine laparoscopy, semen freezing technology, sex-sorted semen and challenging cases of mare or stallion infertility.

Lee also provides referral consultancy services to equine vet clinics in New Zealand, SCEC Pty Ltd and EquiBreed OZ in Australia.

Some stallions are resident at Equibreed while others are delivered to the facility. The horse is taken out into the “phantom” yard and is persuaded to mount the “phantom” (a padded pretend mare). Semen is collected in an artificial vagina. This is a lot safer than collecting it on a mare.

Semen is brought into the lab and examined for motility, volume and sperm numbers. A substance is added to the semen, which is intended to keep the semen alive. Motility is assessed using a computerised model which also videos the assessment for their records.

If semen is processed for storage, there’s a semen extender added before it is put into liquid nitrogen.

Once the semen is processed Lee says the focus is on preparing the mares for AI. She says the key is the timing. Mares can be in season for 5 to 7 days and then might ovulate in the last two days of being in estrus. If you get the timing wrong you won’t be able to produce a foal.

AI has not been hugely successful in the past. Gisborne horse breeder Bruce Holden of Ngahiwi horses says success rates were very low until Lee came along. He says he has had 90 to 100% success rate with Lee’s team in charge of the AI process.

If they’re using frozen semen it only lives for 6 -12 hours, so they need to scan the mares within 4 to 6 hours of ovulation so the semen gets the best chance of being viable. With fresh semen the management isn’t quite so tough because the semen lives longer.

Another challenge is the seasonality of the business, since the breeding season for horses runs from October until March, so all the income has to be generated within a six-month period.

Adding to the challenge is that in New Zealand, the breeding and the competition seasons for horses are very close, making it very hard to pull out a competitive mare for breeding without affecting its competition opportunities.

Embryo transfer work takes place early or late in the season with competition mares. 7 or 8 days after ovulation, the team flushes the embryos out of the mare’s uterus and places that embryo in a surrogate mare.   Like the AI, Lee says attention to detail is required to get good results from embryo transfer.

She says embryos from Europe will soon be imported into New Zealand, which will be an exciting development. She says if they can bring European genetics to New Zealand, grow them on here and then return those animals, everybody wins.

Lee now has the technology to freeze embryos successfully. This is a great opportunity for New Zealand breeders as she can freeze embryos and transfer them when it suits the owner or even import and export embryos. Maurice Beatson, one of New Zealand’s leading show jumpers, recently purchased the first frozen “show jumping” embryo created in New Zealand.

Lee and some of the students she’s supervised have worked on projects such as sex-sorting semen and collecting semen from gelded colts (meaning you can geld a stallion and still extract his genetics for breeding).

Lee also says there’s research looking at using at extremely low doses of semen for successful AI. There’s also been work on stem cell research largely aimed at lameness in horses, which is achieving good results in racehorses and eventers.

A longer-term project is looking at the impact of the weather on a mare’s fertility.