FEEDLOT PERFORMANCE, CARCASS COMPOSITION AND MEAT QUALITY OF FREE-RANGE REARED PIGS

The effects of the housing system (confinement versus free-range) and season (summer versus winter) on growth performance, carcass compositi on and meat quality were determined from commercial pigs with known NN genotype at the halothane locus. Free-range-housed pigs reared from 2 5 to 105 kg required 16 +/- 1.2 (SEM) more days to reach market weight compared with confinement-housed pigs. Housing did not affect feed re quirements during the summer, but food consumption increased by 13.7% for free-range pigs during the winter. Confinement-reared pigs had a 0 .75 +/- 0.28 kg heavier commercial carcass weight than free-range-rear ed pigs. While there was no difference in carcass fat thickness, muscl e depth was 2.4 +/- 1.02 mm greater in free-range-reared pigs with inc reased predicted lean yield from 59.1 +/- 0.24% to 59.8 +/- 24%. Free- range-reared pigs had heavier butts, loins and hams, and lighter belli es, which increased their wholesale carcass value by 2.9%. Furthermore , they had greater dissected lean in the picnic (2.0%) butt (4.0%), lo in (4.5%) and ham (2.0%) with no compromise to pork quality. If the wh olesale price is adjusted for the increased lean content of each cut b y an additive or multiplicative model, apparent value was further incr eased to 5.7 or 8.1%. While these results suggest a beneficial effect on carcass merit when rearing hogs in outdoor facilities, they further suggest potential benefits to carcass grading using developing techno logies that recognize differences in carcass conformation.