The aim of this study was to determine the effect of electrical stimulation applied soon after slaughter on the meat quality of pork. The examinations were carried out in a South German EU approved slaughterhouse under routine slaughter conditions. Electrical stimulation was performed in the slaughterhouse using the device Beef Low Voltage Stimulator, Modell BV 80 (Jarvis, New Zealand), a stimulation apparatus for cattle. A group of stimulated (n = 492) and a control group of nonstimulated carcasses (n = 267) was included in the study. The main parameter pH value, as well as electrical conductivity, water-holding capacity and reflection value were determined and related to each other. In addition, individual influences of the slaughter animals (origin, gender, class) and influences of the slaughterhouse (staff, water used while driving animals into the restrainer) were recorded. Analytical values were obtained from carcasses of 150 farms of origin and the results observed with and without stimulation were compared. In the case of three farms of origin details concerning breed, stabling, transport and lairaging were also registered. These carcasses originated from the Bavarian Hybrid Pig Breeding Program, the German Hybrid Pig Breeding Program and the Danish Hybrid Pig Breeding Program.

Electrical stimulation triggered an advanced onset of glycolysis, which resulted in an accelerated decline in post mortem pH values. Differences in meat quality due to individual influences of the slaughter animals or the slaughterhouse, which were observed in the pH of nonstimulated carcasses, were levelled out after application of electrical stimulation. The breed of the slaughter animals in combination with the duration of lairaging in the slaughterhouse considerably influenced early post mortem pH development. The electrical conductivity values measured in this study confirmed literature data. Yet, new insights were gained inasfar as the values of electrical conductivity were determined to be clearly elevated already 30 min post mortem after stimulation. The maximum difference was detected 4 hours post mortem amounting to an increase of the average conductivity value of approximately 47 % after stimulation. The reflection values of the stimulated slaughter pigs were shown to be clearly elevated in comparison with the values of the nonstimulated carcasses. Yet, the range of the values measured varied similar to those of the electrical conductivity and did not in all cases permit a sure evaluation of the meat quality to be expected in the individual animal. The nonstimulated slaughter animals showed higher average Q-values which indicated a superior meat quality concerning the PSE properties of the slaughter pigs.

Electrical stimulation resulted in the development of paler and more exudative meat in all carcasses and therefore in an enormous increase of carcasses with obvious PSE qualities. It is liable to cause a deterioration in meat quality and is not to be recommended for pork production.