POSTMORTEM CHANGES IN THE MUSCLE OF HORSE MACKEREL SACRIFICED BY NECK-BREAKING

Specimens of horse mackerel were killed by stabbing in the spinal bulb or neck-breaking. After death, the fishes were stored at 0 degrees C. The rate of progress of rigor-mortis, and the rate of change of conce ntrations of energy-related compounds and breaking strength of the dor sal muscle were investigated, The rate of progress of rigor-mortis in the neck-breaking group was slower than that in the stabbing in the sp inal bulb group. The concentrations of ATP and creatine phosphate in t he dorsal muscle immediately after killing in the neck-breaking group mere higher than those in the stabbing in the spinal bulb group. Conve rsely, the initial values of concentrations of IMP and lactic acid wer e lower in the neck-breaking group. No significant differences were ob served in the changing rates of breaking strength of the muscle and K- value. From these results, if. was considered that the killing procedu re by neck-breaking was able to delay the changes in rates of rigor-mo rtis and energy-related compounds in muscle compared with the treatmen t by stabbing in the spinal bulb.