Submitted to: Florida Beef Cattle Short Course
Publication Type: Review Article
Publication Acceptance Date: 5/3/2000
Publication Date: 5/3/2000
Technical Abstract: Superovulation and embryo transfer techniques can be successfully used to accelerate the production of desirable animals. These technologies also are useful for the safe and efficient movement of cattle genetics on a world-wide basis. In addition to the importance of selecting the donor cows and sires used to produce the embryos it is also important to consider the recipient dams. In our studies conducted in the subtropics of Florida, using available estrous synchronization protocols, similar calving rates were observed after the transfer of embryos to Angus and Brahman recipient dams as well as to Angus and Senepol recipient dams. Although breed of recipient dam is likely to significantly influence length of gestation and birth weight, the effect of breed of recipient dam on weaning weight was inconsistent. Reproductive characteristics do differ between tropical and temperate breeds of cattle and must be considered in designing synchro- nization and superovulation protocols. However, embryos can be successfull recovered and transferred from tropically adapted cattle including the Brahman, particularly when conducted in the tropics or subtropics. Trop- ically adapted Bos taurus breeds, such as the Senepol and Romosinuano appear to be as heat tolerant as Brahman and may offer some alternative traits for beef cattle producers. In the future, new estrous synchroniza- tion and superovulation regimens will undoubtedly be designed for better control of the estrous cycle and superovulation. These new products and regimens will need to be examined using tropically adapted cattle in warm regions of the United States to ensure the efficient propagation of superior genetics to a large segment of the U.S. beef cattle population and producers.