Histochemical characterisation of high-value beef muscles from different breeds, and its relation to tenderness.

The aim of the present study was to characterise and compare the muscle fibre traits of five muscles: longissimus lumborum (LL), semitendinosus (ST), biceps femoris (BF), semimembranosus (SM) and psoas major (PM) collected from four cattle breeds (Aberdeen Angus, AA; Gascon, GS; Holstein, HO; Fleckvieh, FL) differing in maturity type (early-and late-maturing) and production purpose (beef and dairy), but maintained under identical husbandry conditions. The relationships between histochemical characteristics and instrumental meat tenderness (WarnerBratzler shear force) were evaluated. The most significant differences in muscle fibre traits were seen in the hindquarter muscles of Aberdeen Angus and Gascon cattle, with muscle location also having a large effect on tenderness. Under the identical husbandry practises used, the differences in muscle fibre composition were seemingly linked more so to muscle location and maturity type of the breed, rather than the production purpose of the breed. Based on their effects on high-value muscles in beef breeds, continuous evaluation of muscle fibre traits together with their association with various meat quality traits is required, as breeds progress genetically. However, various intrinsic and extrinsic factors, such as husbandry practises, need to be controlled so that accurate conclusions may be drawn from such investigations.