Alternative Market Weights for Swine. II. Carcass Composition and Meat Quality

An experiment was conducted to investigate the effects of extended slaughter weight on carcass composition and meat quality in a population of swine selected for carcass leanness on a full feed regimen. A total of 126 gilt and 132 barrow carcasses was evaluated over a range of slaughter weights from 73 to 137 kilograms. Growth of carcass and individual primal cuts was linear over the entire weight range studied. Sex interactions were evident for ham only. Expressed as a percentage of side weight, shoulder and ham decreased and loin and belly increased as weight increased. Sex × weight interactions for percentage ham and belly were observed. Examination of carcass dissection data indicated linear accumulation of lean, fat and bone, with lean accumulation continuing uninterrupted for both sexes up to 137 kilograms. On a percentage basis, however, important sex × weight interactions were evident, reflecting the increased advantage of gilts in carcass leanness as slaughter weight increased. It was concluded that live slaughter weights of up to 126 kg did not adversely affect carcass lean yield of gilts and that there may be potential advantages in carrying certain pigs to well above conventional slaughter weights. Notwithstanding continuing growth of lean tissue, however, slaughter weights in excess of 90 kg in barrows on the present feeding regimen resulted in decreased carcass lean yield. Pork quality was not adversely influenced by the extension of slaughter weight for either sex.