Growth performance and carcass traits of boars raised in germany and either surgically castrated or vaccinated against gonadotropin-releasing hormone

Abstract

Objectives: To test the effect on male growth performance and carcass traits in a typical German production operation comparing vaccination against gonadotropin- releasing hormone (GnRH) with surgical castration early in life to control boar taint. Material and methods: Boars were either surgically castrated within the first week of life (Gl; n = 91), vaccinated against GnRH (Improvac; Pfizer Animal Health, Louvain- la-Neuve, Belgium) twice at 10 and 21 weeks of age (G2; n = 89), or not treated (G3; n = 12). Animals were slaughtered at 25 to 26 weeks of age. Growth performance (overall daily weight gain; Gl and G2) and carcass traits (% lean muscle, loin muscle, and backfat thickness; Gl and G2) were recorded, and intensity of boar taint was organoleptically assessed (G2 and G3). Results: Boar taint was observed in intact boars (G3) but not in vaccinated boars (G2) at slaughter 4 to 5 weeks after the second vaccination. The carcasses of G2 boars were significantly leaner and had less backfat than those of surgical castrates (G1). There was a tendency of G2 boars to have greater weight gain than G1 pigs during growing-finishing. Implications: Vaccination of boars against GnRH, as performed in this study, reliably controls boar taint and yields superior carcass traits when compared with surgical castration.