The effect of nutrition on muscle pH decline and ultimate pH post-mortem in sheep and cattle

This paper reviews the effect of nutrition on rate of post–mortem pH decline, pH change after electrical stimulation (delta pH) and ultimate pH in skeletal muscle of sheep and cattle. The importance of muscle glycogen concentration as a determinant of ultimate pH, delta pH and rate of pH decline post–mortem is illustrated. As delta pH and rate of pH decline are increased by high muscle glycogen concentration, nutrition may affect the rate of pH decline through its effect on glycogen concentration. Muscle type also has an effect on the rate of pH decline: white muscles comprised of fast glycolytic fibres have greater rates of pH decline and delta pH than red, oxidative muscles. The effect of nutritional restriction on muscle fibre type and rate of pH decline through its effect on physiological maturity and metabolic enzyme expression is discussed.