New trends in immunocastration and its potential to improve animal welfare: a mini review

Castration is frequently used to reduce aggressive behavior and improve the meat quality of animals. Traditionally, surgical and mechanical castration are used to sterilize the animals, but these approaches are associated with a high level of pain, stress, long recovery periods, and post-operative infections. Immunocastration is a new animal-friendly, painless alternative castration technique that is used to prevent undesired sexual behavior, reduce aggressive behavior, prevent unwanted pregnancy, control wildlife populations and wandering species, enhance growth performance, improve meat quality, and treat various sex hormone–dependent disorders. The mechanism of immunocastration includes the immunological block of the hypothalamic-pituitary–gonadal axis (HPG axis) which inhibits gonadotropin secretions, causes atrophy of gonadal tissues, and inhibits gametogenesis, resulting in infertility in both female and male mammals. By the mid-1990s, various immunocastration vaccines have been tested in different animal models to achieve successful castration effects. Recently, genetic immunocastration especially DNA vaccine has gained increasing attention due to its safety, being animal-friendly, and being easy to use. This review aims to evaluate the potential of traditional castration methods, as well as the current status of immunocastration vaccines, their effects, and future prospective.