Effect of terminal sire line and timing second vaccination on effectiveness of immunocastration, performance, and carcass and meat quality

Performance (from 10 weeks until slaughter), carcass and meat quality, and effectiveness of immunocastration was compared in crossbred offspring of stress positive (BP+) and negative (BP-) Belgian Pietrain and Canadian Duroc (CD) given the second vaccination of Improvac (R) at different times (4, 6, 8 weeks before slaughter). CD offspring had a significantly higher daily gain (DG) and feed intake (DFI), and lower predicted lean meat percentage (LMP) and dressing yield compared to BP+ and BP-, while feed conversion ratio (FCR) did not differ. CD offspring had significantly lower drip loss and higher pH(i), intramuscular fat content than BP+ and BP- (except for pH(i)). No significant effect of vaccination time on DG nor FCR was observed. Predicted LMP tended to increase as time-post injection decreased, while meat quality was minor affected. Earlier vaccination had no effect on the effectiveness of immunocastration based on testosterone and GnRH-binding.

Automated summary

This study compared the effects of different immunocastration times on the growth performance, carcass quality, and effectiveness in piglets. The results showed that Canadian Duroc offspring had better growth rate and feed intake compared to Belgian Pietrain offspring, but slightly inferior meat quality; however, vaccination time did not significantly affect growth performance and feed conversion ratio, while predicted lean meat percentage seemed to be influenced.