A comparison of the carcase characteristics of pigs immunized with a ‘gonadotrophin-releasing factor (GnRF)’ vaccine against boar taint with physically castrated pigs

Evaluating the effect of using a GnRF vaccine against boar taint on the carcase characteristics of boars, vaccinated pigs were compared with physically castrated. In total, 554 male pigs were randomly assigned to treatment groups. T01 comprised physically castrated pigs in the first week of life, T02 comprised pigs vaccinated twice before slaughtering. There was neither significant difference between the groups in terms of average liveweight nor in the hot carcase weight. The mean dressing percentage was 1.5% higher for T01 than for T02 (P < 0.0001). The lean meat percentage was significantly higher in T02 (P < 0.0001). Backfat and backmuscle thickness were significantly higher in T01 (P < 0.0001 and P = 0.0099, respectively). Within the EUROP grading vaccinated pigs were in favour (P = 0.0034). There were no significant differences using the AutoFOM system: weights of the boned ham, boned shoulder and loin (P = 0.5102, P = 0.8881 and P = 0.1919, respectively). The weight of the belly was significantly higher (P = 0.0042) in T01 while the lean meat percentage of belly was significantly higher (P < 0.0001) in T02.