Preliminary examination of the histochemistry of the semitendinosus muscle microstructure in Bali cattle (Bos javanicus) and the correlations with muscle score

Bali cattle (Bos javanicus) are a local breed from Indonesia with the potential for beef production, but its meat has been reported to be tough. This indicates that there is a need to develop various methods that can be used for assessment to improve the quality of the meat. One such method is muscle scoring (MS), which is often used to predict the amount of meat in the carcass from live animals, but the muscle microstructure contributing to the quality is often neglected. Therefore, this study aims to evaluate the correlation between the muscle score of Bali cattle and the quality of muscle microstructure in terms of myofibril morphometric and connective tissue composition using a histochemistry approach. The population consisted of 31 Bali cattle, and MS was performed by evaluating the muscle line using a range of 1 to 15. The three individuals with the highest scores (Hi) and the three with the lowest (Lo) were sampled for semitendinosus muscle microstructural observation. The results showed that cattle in the Hi group had a higher surface area of myofibril and sarcomere length, but had a significantly lower relative percentage of intramuscular collagen compared to others in the Lo group (p < 0.05). Generally, muscle score had a positive correlation with body weight, surface area of myofibril and sarcomere length. In all cattle, the fibres identified were similar, where the thick types were dominant in the epimysium and perimysium, followed by the thin variants. Furthermore, the endomysium prominently contained non-fibrous or other types of fibre. This study can provide the basic data that can be used as a pilot for future studies of muscle score assessment in Indonesian cattle.