With breed registries admitting more than one foal per mare per year, the use of frozen embryos is becoming more mainstream.

The freezing of equine embryos is getting increased attention from researchers. For years embryo freezing for horses has lagged well behind the same procedure in the bovine industry. The reasons have been quite basic. First, equine embryos are more difficult to harvest in suitable numbers and more complicated to freeze than their bovine counterparts.

Second, there hasn’t been that much demand. One reason for the lack of demand was the fact that many registries imposed restrictions on embryo transfer of frozen embryos. In a number of cases, those restrictions recently have been lifted.

It now appears, says E.L. Squires, MS, PhD, professor in the Department of Biomedical Sciences at Colorado State University’s (CSU) veterinary school, that embryo freezing is heading toward its own niche in the horse industry.

The reasons are in direct contrast to the reasons for slow progress in the past. Now, science is at work to superovulate mares–so they release greater numbers of eggs and, thus, produce multiple embryos–and new and improved methods have been found to successfully freeze equine embryos