Fat quality of South African pigs with different carcass classification characteristics
The carcasses of South African pigs are classified into six groups (PORCUS) according to their calculated lean meat content and measured backfat thickness. Pigs with the highest lean meat content and lowest backfat thickness belong to the P group. Fat quality of backfat from 2107 pig carcasses, sampled within the different pork classification groups at a major South African pig abattoir, was evaluated to determine the relationship between carcass classification and backfat quality. Extracted fat was used to determine the iodine value of these samples. Significant differences in carcass characteristics and iodine value were observed between the classification groups. Improved fat quality, indicated by a lower iodine value, was associated with increased backfat thickness and decreased lean meat content. The P and O classification groups (with backfat thickness <17 mm) could not conform to international standards proposed for good technological quality backfat. The C, U and S groups (with backfat between 23 and >32 mm) possessed good technological quality backfat. Backfat from the R group had borderline fat quality. Correlation analyses were employed to acquire equations to describe relationships between iodine value and carcass classification data. The French classification system predicts fat quality by utilizing backfat thickness and lean meat content. It was proposed, through modification of the French system, that South African pig carcasses with a backfat thickness >17 mm and a lean meat content <67% would potentialy deliver good quality backfat. Results from this study indicate that carcass classification data may be used to improve the probability of selecting pig carcasses with good quality fat.
Keywords: Backfat, fatty acid(s), iodine value, meat processing, South Africa, survey, swine