SUMMARYStage of maturity, genetic background, and post‐slaughter holding temperature have been studied in relation to their effects on the rate of post‐mortem glycolysis, change in gross muscle morphology, and alteration of muscle protein solubility. Muscle from 5‐lo‐kg animals tended to have more glycogen and less myo‐globin as well as less total nitrogen than muscle from 250–300‐kg animals. Glycolytie rate appeared to be slightly faster in the postmortem muscle of mature animals, but differences among weight groups were minor. Muscle from mature animals exhibited a greater loss of color after slaughter. Protein solubility also decreased to a greater extent in these mature muscles. This was especially evident in the myofibrillar fraction. Post‐slaughter holding temperature did not affect the rate or ex‐tent of glycolysis in the muscle, hut chilling gave benefits to subjective score for color and juice‐retaining capacity. It also tended to make the loss of protein solubility less severe, particularly for the myofibrillar fraction.