Cold shortening capacity and beef muscle growth

Abstract

AbstractCold shortening capacity is related to animal growth. For unloaded strips of beef sternomandibularis muscles the degree of cold shortening developed at 2 °C during the pre‐rigor period increased from approximately 0.2 for small young calves to 0.6 for large old bulls. This growth‐dependent capacity to cold shorten is even more pronounced in muscle strips shortening isometrically. Thus in terms of power development, it increases forty‐fold with the growth of beef sternomandibularis muscles to their mature sizes. In contrast, temperature sensitivity of the phenomenon is virtually the same for both small and large animals with the tendency to cold shorten declining in both to zero at 35 °C. These findings are important to meat chilling since they imply that cold shortening will be more pronounced the larger the carcass. This is offset to a degree by the fact that large carcasses will chill more slowly than smaller carcasses.