The Impact of Deviation of the Stun Shot from the Ideal Point on Motor Paralysis in Cattle.

The effect on motor paralysis of a deviation in the stun shot placement from the ideal point on cattle skulls was monitored in 627 bovine animals (271 bulls and 356 cows) stunned with a captive bolt during slaughter in a slaughterhouse. The number of animals that experienced motor paralysis and the necessary fall of the animal in the stunning box were recorded after the stun shot. Subsequently, the position of the stun shot was measured on the skull of the slaughtered cattle in relation to the ideal point on the skull, and at a deviation from the ideal point, the quadrant on the skull in which the bullet was located was determined. The results show that with the increasing distance of the placement of the stun shot from the ideal point on the skull, the incidence of failure to induce motor paralysis in cattle increases significantly ( < 0.01) from 2.4% (within 3 cm of deviation) to 72.2% (at deviations ˃ 7 cm). There was a significant increase in the failure to induce motor paralysis in bulls as well as in cows, but this was more frequent in bulls regardless of the magnitude of the deviation from the ideal point (with the exception of a distance greater than 7 cm where the chances of inducing motor paralysis in bulls and cows are equally low). The incidence of failure to induce motor paralysis in cattle was not dependent on the placement of a stun shot in various quadrants on the skull. With the increasing deviation in any direction from the ideal point, the likelihood of effective stunning of cattle decreases. The results are important from the animal welfare point of view of the slaughter of cattle, and demonstrate the necessity of optimum placement of the stunning shot on the bovine skull in order to achieve the successful motor paralysis of cattle during their stunning at the slaughterhouse.