Superstimulation of ovarian follicles in cattle: Gonadotropin treatment protocols and FSH profiles

• Published in: Theriogenology 2020-07, Vol.150, p.353-359
• Main Authors: Bó, Gabriel A., Mapletoft, Reuben J.
• Format: Article
• Language: English
• Subjects: Animals; Bovine; Cattle - physiology; Clinical Protocols; Dose-Response Relationship, Drug; Embryo; Embryo Transfer - veterinary; Estrus Synchronization; Female; Follicle Stimulating Hormone - administration & dosage; Follicle Stimulating Hormone - pharmacology; FSH; Gonadotropins - pharmacology; Oocytes - drug effects; Ovarian Follicle - drug effects; Ovaries; Ovulation Induction - veterinary; Superovulation; Superovulation - drug effects
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2020.02.001

The objective of ovarian superstimulatory treatments in cattle is to obtain the maximum number of viable embryos by stimulating growth of antral follicles and ovulation of competent oocytes. While factors inherent to the donor animal are critical, an increased knowledge of ovarian physiology, gonadotropin biochemistry and the ability to manipulate ovarian function have provided alternatives for the design of simple and successful protocols for superovulation in cattle. Recent protocols have also been made more user-friendly and allowed for the grouping of donors for successful superovulation. Although the number of reports associating FSH profiles with superovulatory response is limited, studies designed to reduce the number of FSH treatments necessary to induce superstimulation may provide guidance for the development of optimized gonadotropin treatment protocols. Although high peak levels of circulating FSH following a single administration of Folltropin-V have been shown to be associated with a reduced superstimulatory response, the ideal treatment protocol would seem to be to increase circulating FSH levels to values comparable to those required for the induction of follicle wave emergence, and to maintain these levels for at least 72 h (or 36 h for superstimulation prior to ovum pick-up) to allow follicles to reach an ovulatory size and acquire the capacity to ovulate. •The objective of superovulation is to obtain the maximum number of viable embryos.•Several hormonal treatments have been investigated during the past 40 years.•The reports associating FSH profiles and superovulatory response are limited.•However, analysis of these studies might help to find the ideal treatment protocol.•The search for a simple and consistent protocol warrants further investigation.