August 6, 2013
First Przewalski’s Horse Born As A Result Of Artificial Insemination
redOrbit Staff & Wire Reports - Your Universe Online
The recent birth of a Przewalski's horse at the Smithsonian Conservation Biology Institute (SCBI) has given new hope for the future of the rare and endangered species, which at one time was believed to be extinct.
"Anne is a young, first-time mother," SCBI supervisory biologist Dolores Reed said in a statement. "She had a normal pregnancy that lasted 340 days and the foaling lasted less than 10 minutes. I've raised a lot of foals and other hoofed stock over the years, but this filly feels like an extra-special triumph for us and her species."
While the pregnancy officially lasted just 340 days, Shenk said the birth was actually seven years in the making. According to Reed and reproductive physiologist Budhan Pukazhenthi, the institute's staff had to begin by learning how to work with the wild horses. Then they had to devise a reproductive game plan.
First, they established a reward system devised to allow them easier access to mares for the collection of urine samples. Next, they needed to learn how to successfully collect semen from stallions, monitor the hormone levels of the mares, and figure out how Przewalski horse estrus cycles compared to those of domestic horses.
"Previous attempts to artificially inseminate the mares were unsuccessful. But last year, after consultation with experts at Auburn University, Pukazhenthi tried a different method that minimized the distance that the sperm had to travel in the uterus," Shenk said. "It worked, making the yet-to-be-named filly the first Przewalski's horse of its kind."
He and Reed told National Geographic, despite increases in the Przewalski's horse through natural means, the limited number of mares and stallions in the wild could result in inbreeding. They believe artificial insemination will help diversify the population, while also allowing ideally matched animals to remain in one location - thus limiting the cost, safety and space issues that typically arise when transporting wild horses for mating purposes.
According to Mother Nature Network's Russell McLendon, Przewalski's horses were declared extinct in the wild 44 years ago. Fourteen survived in zoos, however, and thanks to the breeding efforts of conservationists, there were enough members of the species to begin reintroduction roughly two decades ago.
In 2008, the species was upgraded from extinct to endangered, and McLendon reports there are currently approximately 500 Przewalski's horses living in the wild - all of which still carry the genes of the original 14. In addition, there are about 1,500 more living at zoos and breeding centers, but it has been challenging finding a way to increase the population while also maximizing genetic diversity.
Two years ago, a sequencing of the Przewalski's horse genome revealed the species is far more distantly related to the domestic horse than researchers had previously hypothesized. While scientists had previously believed the two creatures had diverged around the same time horses were first domesticated (6,000 to 10,000 years ago), the divergence actually occurred much earlier than that - perhaps as much as 160,000 years ago.