Inhibin Immunization to Enhance Reproductive Performance in Livestock: A Review

Reproductive efficiency substantially determines livestock productivity, and suboptimal fertility continues to limit productivity across species. Inhibin immunization represents a novel strategy to enhance fertility by neutralizing inhibin's negative feedback on follicle-stimulating hormone (FSH) secretion. This comprehensive review synthesizes evidence from ruminants (cattle, sheep, goats, camels, and buffalo) and non-ruminants (pigs, donkeys, rabbits, and avian species), evaluating inhibin immunization mechanisms and reproductive outcomes. Immunoneutralization of inhibin consistently elevates FSH, activin A, and estradiol, thereby promoting ovarian follicular recruitment and spermatogenesis. In females, this approach has been widely reported to increase ovulatory activity and improve embryo production and quality. In males, immunization enhances testicular function and semen quality while mitigating seasonal infertility. However, species-specific variations in response and dose-dependent luteal suppression (particularly in pigs) necessitate optimized protocols. While inhibin immunization shows consistent benefits when integrated with multiple ovulation and embryo transfer (MOET) and in vitro fertilization (IVF), standardized protocols and long-term fertility data remain insufficient for commercial implementation. This review identifies critical evidence gaps and safety considerations essential for clinical translation.