RACTOPAMINE HYDROCHLORIDE AND IMMUNOCASTRATION EFFECTS ON FRESH PORK PROPERTIES

摘要

One hundred ninety seven crossbred (Tempo, sires and Topigs 40, dams) pigs were penned in 12 groups with a total of 6 treatments and duplicate for the 2-way interaction, ractopamine (RAC, 7.5 mg/Kg during 21 days) versus sex (female, FE, male pigs castrated physically, PC, and immunologically, IC) aiming to clarify the interaction of these two technologies on pork quality traits. The statistical results showed no significant difference for both, RAC treatment and sex considering the ultimate pH measured in Longissimus dorsi (LD) and Semimembranosus (SM) muscle as well as Minolta LD colour (L~*, a~*, and b~*). Nevertheless, the inclusion of RAC increased the objective shear force significantly (3.61 kg, P < 0.03) compared to the control pigs (3.36 kg) and IC pigs also presented greater (3.67 Kg, P < 0.04) shear force values than PC (3.30 Kg). The present study shows no interactive effect of ractopamine (RAC) and sex on the pork quality traits evaluated. The inclusion of RAC increased toughness of pork meat, however the shear force differences found in this study would not be detected by an untrained taste panel, accordingly to the scientific results reported from other authors.