Studies in electrical stimulation: Post-mortem decline in nervous response in lambs

Abstract

A study has been made of the effects of electrical stimulation, either indirectly through the nerves or directly through the muscles, on glycolysis in lamb hind leg muscles. Responses were affected by delay before application and the stimulating voltage. At 5 min post mortem the same fall in pH during stimulation (ΔpH) and subsequent increased rate of pH fall (dp H/dt) occurred in muscles stimulated both directly and indirectly with 12 V. With 200V, ΔpH was 50% greater in muscles stimulated directly and 30% less if stimulated indirectly. At 30 min post mortem there was very little effect of stimulation at either voltage on glycolysis when muscles were indirectly stimulated, indicating that the nerves had lost their capacity to trigger muscles to contract. In contrast, if the legs were stimulated directly, maximum ΔpH and dpH/dt values were achieved with 200 V pulses. The significance of these findings to the application of electrical stimulation to commercial meat processing is discussed.