GnRH-Based Immunocastration Vaccines: Comparative Analysis and Role in Boar Taint Reduction

Boar taint is a persistent challenge in pork production, caused primarily by the accumulation of androstenone and skatole in adipose tissue. It affects 5-40% of uncastrated male pigs and is perceived negatively by a substantial proportion of consumers, with skatole detectable by almost all individuals. Traditional surgical castration effectively prevents boar taint but is increasingly criticized on animal welfare grounds. Immunocastration using gonadotropin-releasing hormone (GnRH) vaccines has emerged as a promising alternative, providing reversible suppression of reproductive function while maintaining growth efficiency. This review integrates current knowledge on the biochemical basis of boar taint, evaluates the performance of commercial vaccines such as Improvac^® and GonaCon^®, and examines economic, regulatory, and consumer factors influencing adoption. Immunocastration presents limitations due to variability in immune responses, the need for multiple doses, and challenges related to public perception. To address these challenges, intensive research is underway on single-dose formulations, precision adjuvants, and advanced delivery technologies, all of which are expected to drive the next generation of immunocastration vaccines.