Development of Recombinant Follicle-Stimulating Hormone for the Superovulation of Cattle: A Review

Embryo transfer technology is extensively utilized in cattle breeding, with superovulation serving as its foundation. Superovulation currently relies on the administration of exogenous hormones to stimulate follicular development and maturation in the ovaries, with porcine pituitary-derived follicle-stimulating hormone (FSH) being the most commonly used. However, pituitary-derived FSH requires multiple injections, contains luteinizing hormone (LH) and other proteins, and carries a risk of disease transmission. The development of recombinant FSH proteins through protein recombinant technology represents a significant research direction for addressing the aforementioned challenges. Over the past 30 years, extensive studies have been conducted on the development of recombinant bovine, ovine, or porcine FSH. Nevertheless, to date, no commercially recombinant FSH has been widely applied in the superovulation of cattle. This review provides an overview of the molecular design, selection of expression systems, and biological activity of recombinant bovine, ovine, or porcine FSH. This review also summarizes the results of utilizing recombinant FSH in superovulation protocols for cattle. The utilization of recombinant proteins as an alternative to traditionally extracted products in livestock production represents an irreversible trend. The livestock industry is highly sensitive to costs; therefore, it is essential to develop high-quality and cost-effective recombinant FSH products through appropriate molecular design and the use of suitable expression systems.