Muscle fibre types and beef quality
Meat comes from the transformation of the skeletal muscle of meat animals after slaughter. Cattle are generally reared to produce either milk or meat, and breeds are purpose-adapted to each type of production. However, dairy-herd animals such as culled cows, bullocks or heifers represent a large share of meat consumed (more than 50% in the European Union (EU)). In the United States and Australia, most beef from males is from steers. The age of the slaughtered animals is, therefore, highly variable, as it extends from calves aged a few weeks to cull cows that may count up to 15 years. The upshot is that there is high variability in the cattle providing meat and, consequently, high variability in meat quality. Pre-slaughter stress, slaughtering technology and the differences in muscle composition are known to be partly responsible for the heterogeneity of meat quality.