Growth performance, reproductive organs and carcass characteristics of immunocastrated pigs

Abstract

To evaluate growth performance, reproductive organs and carcass quality 40 piglets were used, 20 surgically castrated (CQ) and 20 immunocastrated (IM). The daily weight gain (GDP) was higher in IM pigs after revaccination, which increased body weight (PV) at weeks 22, 23 and 24 of age (P<0.01), slaughter weight (PS) and hot carcass weight (PCC; P<0.05). The feed conversion rate (CA) was lower in IM pigs after the first immunization (P<0.01) due to increased plasma testosterone concentration after this event and its tendency to remain high after revaccination. The reproductive organs of IM pigs were similar to those reported in previous studies that confirm their atrophy. Fat thickness at Gluteus medius was similar (P>0.05) between treatments. The number of skin lesions (LES) was also similar (P>0.05) due to the similar incidence of fights reported. IM pigs showed greater leg length (LP), ham length (LJ), tarsus circumference (CT, P<0.05) and hand length (LM, P<0.01) due to the anabolic effect of testicular hormones and increased blood levels of growth hormone (GH) after revaccination. Immunocastration promotes better CA after the first immunization and increased PV and GDP after revaccination, and favors some economically important carcass traits such as PCC and LJ.