Gestação gemelar em equinos: com ênfase na raça Crioula

Abstract

Twin pregnancies in horses often result in abortion or stillbirths and are responsible for huge losses in the equine industry. Few studies describe reproductive and gestational characteristics in Criollo mares. The aim of this dissertation is to review the main aspects of twin pregnancy in mares and to present scientific results about the incidence of twin pregnancies in Criollo mares. Two articles of bibliographic review were made, the first about the factors that influence the occurrence and the second about diagnostic methods and manipulation of these gestations. The third article presents retrospective study with 814 pregnant mares, demonstrating the incidence of twin pregnancies and multiple ovulations in Criollo mares, correlating the occurrence with reproductive status, age of the mare, use of ovulation inducers and month of breeding season. The incidence of twin pregnancy was 3.44%, being more frequent in single and primiparous mares. Even with low rates when compared to other breeds, it is important to know the risk factors, diagnostic methods and intervention of twin pregnancy to address reproductive aspects in Criollo mares.