Abstract:
The carcass quality of pigs, hence price per kilogram, is primarily determined by hot carcass weight and the subcutaneous backfat thickness at the P2 site. In recent years people have questioned whether P2 is an accurate predictor of carcass composition in modern genotypes. To date many of the reports have largely been anecdotal but recent quantitative data supports this suggestion. Trezona et al. (1999) reported that when the growth of pigs was manipulated through changes in feed intake the P2 changed yet the fat and lean muscle percent in the carcass remained similar, perhaps indicating a redistribution of fat within the carcass. The export of pork carcasses to Singapore has highlighted the variability of fat content in the belly, which is considered to be a premium cut. Carcasses selected for export must meet very stringent criteria, including a specific P2, yet there are complaints that the bellies are too fat. It was hypothesised that some carcasses considered as lean could have increased belly fat due to a redistribution of fat in the carcass.