Innovative strategies for superovulation in cattle

Although superstimulatory protocols in cattle are usually initiated during mid-cycle, the elective control follicular wave emergence and ovulation have had a great impact on the application of on-farm embryo transfer. However, the most commonly used approach for the synchronization of follicular wave emergence involves the use of estradiol which cannot be used in many parts of the world. Therefore, the need for alternative treatments has driven recent research. An approach that has shown promise is to initiate FSH treatments at the time of the emergence of the first follicular wave following GnRH-induced ovulation. Alternatively, it has been shown that it may be possible to ignore follicular wave status, and by extending the treatment protocol induce smaller follicles to grow and reach maturity and superovulate. Finally, the short half-life of pituitary FSH necessitates twice daily treatments which are time-consuming, stressful and subject to error. Recent treatment protocols have permitted superstimulation with a single or alternatively, two FSH treatments, reducing the need for animal handling during FSH treatments.