Random Forest Approach Applied to Italian-French Beef Production Systems: Sex Differences and Key Meat Standards Australia Traits Affecting Beef Eating Quality

International audience

English. The European beef carcass grading scheme prioritizes meat yield over consumer eating experience, in contrast to the Meat Standards Australia (MSA) grading scheme, which is more focused on eating quality. The Italian-French beef production system, mostly characterized by young bulls and heifers imported from France and then fattened within Italian specialized fattening units, has been underexplored using the MSA grading system. This study examines the impact of animal sex on performance, MSA traits, and predicted MSA quality scores (MQ4 and MSA index) using carcasses from an Italian commercial abattoir. It also assesses how animal performance and MSA traits influence predicted beef eating quality. A Random Forest classifier demonstrated high performance with an accuracy of .98, a specificity of .99, and a sensitivity of .97 after 10-fold cross-validations, confirming key traits such as hot carcass weight, European carcass grading scheme fatness score, and general muscular characteristics as being significantly different due to sex. Entire males had greater muscle development, whereas females had notably higher MSA marbling scores, MQ4 scores, and MSA index (P < .05). Furthermore, categorizing the MSA index into 2 classes and applying a similar Random Forest classifier approach revealed that MSA marbling was the primary factor influencing variability of the MSA index. These findings suggest that beef cuts from females may better meet consumer expectations when using the MSA grading scheme in Europe, making them a suitable category for premium beef branding. Grading carcasses from entire male animals for sensory quality is also important, as it demonstrates their potential to produce good-quality beef with a higher lean meat yield; however, their sensory quality tends to be lower than that of heifers and this is in part reflected by their lower marbling score resulting from reduced intramuscular fat deposition.