Interactive effects of feed allowance and ractopamine supplementation on growth performance and carcass traits of physically and immunologically castrated heavy weight pigs

Abstract One experiment was conducted to investigate the impact of feed allowance and ractopamine supplementation on growth, carcass and meat quality traits in barrows and immunocastrated male pigs. Eighty finishing male pigs (95.79 ± 1.71 kg) were allocated in a 2 × 2 × 2 factorial treatment design with two castration methods (CM) (physically (BA) x immunologically (IM) castrated pigs), two ractopamine supplementation programs (RAC) (0 vs 10 ppm in the feed) and two feeding allowance schemes (FA) (restricted (RT) vs ad libitum (AL)) from 131 to 160 days of age. RAC-fed pigs were heavier (P