Effects of FSH treatment in seasonally anestrous ewes on egg production, retrieval, and quality for use in in vitro fertilization procedures

Through the use of assisted reproductive technology (ART), we will be able to extend the use of genetically superior animals, and perhaps increase the number of offspring. These technologies include such procedures as estrus synchronization, superovulation, artificial insemination, embryo transfer, in vitro fertilization (IVF), and cloning. Because they exhibit seasonal breeding and multiple ovulations, sheep have a tremendous potential for improvement and manipulation of reproduction with the use of ART. Most sheep normally exhibit estrous cycles and mate during late summer, fall, and early winter. During winter, spring, and early summer they exhibit anestrous, and thus, are reproductively inactive. Reproductive performance of sheep, in some cases, can be maximized by utilizing this anestrous period or non-breeding season. Manipulations to maximize reproductive performances during seasonal anestrous include hormonal stimulations and estrous synchronization. However, many improvements are still needed to enhance the reproductive efficiency of ewes during seasonal anestrous.