Characteristics of commercially graded pig carcases and their relationships to appraisal system standards

Abstract

Characteristics of eight carcases from each of three grades were examined after adjustment for total dissected weight by analysis of covariance. Grading by visual estimation of depth of fat on the split carcase separated the carcases into three grades in which backfat measurements taken at four standardized positions differed significantly between grades. Premium grade carcases contained a higher percentage of muscle and bone and a lower percentage of fat than carcases of first and second grades. Internal fat and fat plus skin measurements taken over the m. longissimus dorsi differed between grades. Measurements of m. longissirnus dorsi used as indices of carcase muscle content did not differ between grades. Carcase length did not differ significantly between grades. Per cent shoulder did not differ significantly between grades but there were significant differences in per cent middle and ham. Backfat measurements of premium grade carcases satisfied the standards of the Queensland and Downey appraisal systems and the mean measurement of m. longissirnus dorsi of premium grade carcases was awarded 86 per cent of possible marks for this feature on the standard scale of the Queensland system.