Pork quality and histological properties of longissimus muscle from boars and early and late immunocastrated pigs

Immunocastration has been introduced in pig production to reduce boar taint. However, there is not much information on how different schedule of immunocastration affects meat quality, especially muscle histological properties. In this study, carcass and meat quality characteristics, histological properties of the longissimus dorsi muscle, sensory characteristics and fatty acid composition of meat and fat from entire males (EM), late immunocastrated (LIC, first dose 8 weeks before slaughter, second dose 4 weeks before slaughter) and early immunocastrated pigs (EIC, first dose 13 weeks before slaughter, second dose 8 weeks before slaughter) were compared. Fat thickness was greater in EIC than in LIC and EM. Meat quality parameters differed mainly between EIC and EM, as EIC had a higher pH 45, lower electrical conductivity, lighter and more yellowish loins and lower drip loss than EM. EM had a higher protein and moisture content and a lower fat content than EIC and LIC. No major effect on histological properties was observed, however, the percentage of fast-twitch oxidative fibres tended to be lower in both LIC and EIC animals compared to EM. Pork from EM had higher boar taint and lower pork odour and flavour scores and higher pig and boar taint flavour scores. The results of this study show that the immunocastration schedule influences some carcass, meat and fat quality traits and, because of that, it can be modified to obtain the desired final product.