The classification of beef, pork and mutton carcasses in a selected high throughput abattoir in the Eastern Cape, South Afric

Abstract

The carcass classification system was implemented in South Africa as a quality assurance scheme to address consumer uncertainties on the quality of meat they purchase. Although carcass classification is presumed to provide information that can be useful to the meat industry from primary producers to customers, it is argued that the standards used in the system provide inadequate description of the carcass quality related characteristics as it only describes scores and measurements but does not rank for meat quality. Nonetheless, attributes used to evaluate meat quality include eating quality, appearance, freshness, and nutritional value. However, these attributes are neglected in the South African classification system. Two trials were, therefore, conducted to evaluate the classification of red meat and characterise the quality of beef carcasses subjected to the SA classification system at a high throughput abattoir, where five different classification characteristics (age, sex, conformation, bruising and fatness) were used for sheep and cattle carcasses, while the PORCUS classification system was used for pigs. On the first trial a total of 300 animals comprising of 100 cattle, 100 sheep and 100 pigs were used to evaluate the associations between animal traits, carcass traits and carcass classification, while on the second trial beef samples from the Muscularis longissimus thoracis et lumborum of Angus, Bonsmara, Fleckvieh, Non-descript and Simmental genotypes (n=175) were harvested to characterise the quality of beef carcass classes. Significant associations (P<0.05) were found between carcass classes and genotypes of cattle, sheep and pigs. Almost 70 percent of cattle carcasses were in the C classes mainly in the C2 carcass class, while 77 percent of sheep carcasses were of A2 class and 50 percent of pig carcasses were of P class. Significant differences (P<0.05) were observed across genotypes on some meat characteristics (a*, Hab, pH24, TL percent, CL percent and WBSF) of beef carcass classes. The C2 carcass class of Angus genotype had a darker colour (L*) than the Non-descript and Bonsmara genotypes. Redness (a*) of the Bonsmara C2 carcass class differed (P<0.05) from that of Angus, Fleckvieh and Non-descript genotypes. The Non-descript genotype had more yellow subcutaneous fat than all other genotypes. Angus and Simmental genotypes had the toughest meat (40.29 ± 11.62 and 38.71 ± 9.33, respectively), while Non-descript and Fleckvieh genotypes had tender meat (31.53 ± 12.62 and 32.00 ± 7.92, respectively). It was concluded that meat quality characteristics varied within carcasses of the same class across genotypes. Thus consumers might pick differences on the quality of carcasses falling within the same class due to the breed effect which, however, does not form part of the SA classification system.