Artificial Insemination vs. Live Cover
There is an eternal debate in horse breeding on whether to use artificial insemination or live cover. Excellent foals are produced regularly using both methods. This week we’ll explore the pros and cons of both.
Artificial insemination (AI) is a centuries-old practice, stemming from an age-old story of the first AI taking place in 1322. Since then, scientists and veterinarians have improved the method using ultrasound machines, fertility drugs, semen extenders, and antibiotics to boost AI’s success rate.
With experienced handlers and proper equipment, collecting semen from the stallion can be an easier process than live cover. After collection, fresh semen can be used to inseminate the mare directly into her uterus, which is less traumatic for her.
AI also removes geographical restrictions, allows performance stallions to stay involved in their sport, allows for the storage of semen, helps preserve rare breeds, can control disease, reduces the risk of injury, and extends the breeding season.
“There are lots of reasons why I prefer artificial insemination over live cover,” said Tish Quirk, owner of Tish Quirk Equine for The Chronicle of the Horse. “For the safety of the stallions, for one. I don’t need a mare to kick one and end his breeding career. But I also prefer AI for quality control purposes.
The Jockey Club demands that all registered Thoroughbreds be bred through live cover. Their rules state that artificial insemination is “expressly prohibited.” They claim it safeguards the breed from a practice they consider to be harmful to other breeds, like the Quarter Horse.
Economics play a factor, too, of course. Live cover is a limited commodity whose price depends partly on demand. AI makes the product nearly limitless and reduces its value due to abundance. AI also reduces the need for transport services, mare boarding, and small stallion farms, among other breeding services.
Timing is everything, too. Between the mare’s cycle, the semen’s arrival, the owner’s availability, and the vet’s examination, there are many factors that play into a timely impregnation.
“One of the advantages of live cover is that all of the stallion’s sperm are deposited into the mare, so there are typically better conception rates,” said Ellen Stephens, DVM, who owns and runs Laurel, Inc., an equine reproduction facility.
“You’re going to take a precipitous drop in fertility when you start breeding with cooled semen,” says Benjamin Espy, DVM, Dipl. ACT, a private practitioner who specializes in equine reproduction in Texas, says. “Frozen sperm is also under a tremendous amount of duress. Its conception rate is maybe half that of chilled semen.”
Live cover encourages genetic variety within the breed. If the mare has a healthy reproductive system and responds well to the process, live cover can be an excellent option. In some instances, a stallion’s semen does not fit well into a cooled or frozen program, while it may be strong in a live cover or fresh insemination process.
Live cover is significantly more dangerous to the stallion, the broodmare and handlers, and there is no way to be sure that the stallion actually ejaculates into the mare.
Getting the two horses together can be a challenge both schedule-wise and temperament-wise. Most breeders work full-time jobs outside of their farms, so coordinating the veterinarian, stallion and mare as well as the appropriate handlers at the same time can be nearly impossible.
A stallion can cover a mare up to 10 times in a 24-hour period, which increases the likelihood of fertilization, however ensuring this length of access to each other can be one of the most difficult aspects of live cover.
“I think there should be equally high rates with either artificial insemination or live cover,” says John Hurtgen, DVM, PhD, owner of Nandi Veterinary Associates. “I don’t think AI will step you up in terms of conception rates in part because the stallion is going to deliver semen directly to the uterus. Any time you collect, there are things you can do that can negatively impact semen quality, whereas a stallion does not have the opportunity to mishandle semen.
“But at the same time, there are some stallions that don’t cover mares well, or in a normal fashion,” Hurtgen adds. “For example, they ejaculate while they’re dismounting, or the mare moves or outside contamination enters the mare during the cover. And then there are some stallions that are accustomed to being manipulated while others refuse guidance, so there are a lot of scenarios involved in live cover as well.”
This debate comes down to knowing your mare and what time and resources you can dedicate to the process, as well as the result – a healthy and possibly lucrative foal.
“Everybody knows how breeding is supposed to get done, but applying it is not so easy. Getting good semen to the mare, whether it is through live cover or artificial insemination, is most important because the goal is to get the mare pregnant,” emphasizes Hurtgen.