Comparison of meat quality between barrows, boars and boars vaccinated against GnRH

摘要

The aim of this study was to investigate potential differences in carcass and meat quality between barrows, boars and boars vaccinated against GnRH.Ninety-seven barrows (BA), 54 boars (BO) and 100 boars vaccinated against GnRH (Improvac®, IMP) were raised on the same farm. All pigs (hybrid sow x Pietrain boar) received the same diet. Individual lean meat percentage and warm carcass slaughter weight were determined at the slaughter line. On the day after slaughter, loin samples were collected the day after slaughter, vacuum packed and refrigerated until analysis of meat quality (meat colour, ultimate pH, drip loss, cooking loss and shear force). Boar taint of 25 BA, 46 IMP and 53 BO was assessed by evaluation with the hot iron method.Carcass weight was comparable for all three groups. Meat percentage was lower (P<0.001) in BA (57.70%) than in IMP (60.23%) or BO (60.30%). Muscle thickness, measured on the longissimus dorsi (LD), was higher (P=0.021) for BA (62.4mm) and IMP (62.5mm) compared to BO (60.4mm). For IMP (14.2mm) and BO (13.6mm), fat thickness was lower (P<0.001) than for BA (17.7mm).The ultimate pH in the loin was lower (P<0.001) in BO (5.4) than in BA or IMP (both 5.6). The CIELAB colour determinants did not differ between groups (P>0.1). Drip loss was lower (P<0.01) in BA (2.9%) than in both IMP (3.8%) and BO (3.8%). Cooking loss differed significantly (P<0.001), with the lowest loss for BA (28,3%), intermediate for BO (29.8%) and highest for IMP (30.8%). No differences in shear force were found between treatment groups (P>0.1).Boar taint assessment with the hot iron method yielded more boar taint (P<0.001) in BO than in BA or IMP. Vaccination thus reduced the incidence of boar taint.In the present study, carcass and meat quality of IMP was comparable to BO, but with a slightly higher ultimate pH.