Open surgical castration is a routine procedure on neonatal boars to prevent the offensive odor known as "boar taint" which is released when meat from affected animals is cooked. Castration produces a predictable incidence of side-effects including stress, hemorrhage, hernia, infection and mortality, which become more prevalent if castration is performed after weaning. Castration also produces a decrease in growth performance and a higher rate of carcass fat deposition. Pilot studies using chymopapain (enzyme) injected into the testes of boars up to nine weeks of age have shown this method has few side-effects and is an effective alternative to surgical castration. This research plan evaluates the potential of enzyme castration to produce similar results in different age boars up to twelve weeks to improve growth performance and carcass characteristics. A graduated dose of enzyme (mg per gram of testis) will be administered to boars in each test group based upon estimated testes weight. Injected boars will be compared with surgically castrated and intact animals. This research plan will demonstrate any tolerances with enzyme castration, improved safety, growth performance gains and meat quality improvement for boars, which might indicate benefits for use in other livestock species.Applications:Results of this research will demonstrate the practical benefits of enzyme castration in boars of various ages prior to marketing. This research will also enhance general pharmacology information on chymopapain. Achieving the objectives of this plan establishes the basis for a multi-site swine production study and application for approval of a veterinary product. Results of this research should also provide information to adapt enzyme castration to other neonatal livestock (rams and bulls). Further adaptation of the technique to wildlife and pet animals may also be planned and investigated based upon the results of the proposed studies.
