Equine Embryo Production by Means of Double Ovulation Protocols in Colombian Creole Mares

Abstract Equine reproductive efficiency can be improved through the development of technologies such as embryo transfer, where the use of protocols that allow the presence of double ovulations can contribute to increasing the number of offspring per female per year. The objective was to evaluate the presence of double ovulation and embryos in Colombian Creole mares treated with deslorelin and histrelin. Twenty mares were taken and divided into 2 groups as follows: Treatment 1: 150 mg of deslorelin every 12 hours intramuscularly. Treatment 2: 80 mg of histrelin every 12 hours intramuscularly. In both treatments, the hormone was administered until two follicles with diameters greater than 35 mm were found to administer 2,000 U. I of human chorionic gonadotropin and were artificially inseminated 12 to 24 hours later with 300 million motile spermatozoa. Seven days after insemination, uterine lavage was performed to collect embryos. It was found that 60% of the females treated with histrelin presented double ovulation with a follicular diameter of 31.7 mm, and 8 mares had double embryos, while 45% of the mares treated with deslorelin presented double ovulation with a follicular diameter of 33 mm, and 5 mares had double embryos. An association between the presence of double ovulation and the presence of embryos was found in 45% of the mares treated with deslorelin. It is concluded that histrelin treatment presented better results in obtaining double ovulation in mares.