Movements after Captive Bolt Stunning in Cattle and Possible Animal- and Process-Related Impact Factors-A Field Study

Movements in cattle after captive bolt stunning cause problems in the slaughter process and lead to uncertainties in assessing stunning effectiveness. The objective of this study was to categorize and quantify these movements and determine animal- and process-related impact factors, as well as connections to stunning effectiveness and shooting position. In total 2911 cows, heifers, and bulls (dairy, beef, and crossbreeds) were examined (mean age 3.02 years). Movements from landing until at least four minutes after sticking were recorded by action cams (Apeman® A100). Nine movement categories were defined ("kicking hind limb", "twitching", "bending and stretching hind limb", "lifting and bending forelimb", "body arching laterally", "body arching ventrally", and "arching backwards"). According to the movement severity, a score was assigned to each category. The scores were summed, either for certain process intervals, e.g., LANDING (ejection from the stunning box), HOISTING, or STICKING, or for the total time between LANDING and end of the FOURTH MINUTE OF BLEEDING (sum score). Statistical analysis (ANOVA) was performed on the scores. Only 6.6% of cattle showed no movement. Most movements occurred during STICKING and FIRST MINUTE OF BLEEDING, occurring rarely up to 8 min after sticking. While cows moved most at LANDING, bulls and heifers moved more if all process intervals were considered. The sum score was highest in German Angus, Charolais, and Limousin and lowest in Brown Swiss and Simmental. The score at LANDING was highest in German Angus and Black Holstein. The use of pneumatic stunners and an increase in bolt-exit length significantly reduced movements. No impact of stunning effectiveness on movements was found, but only 19 cattle showed reduced effectiveness.

Ballistic study on the penetration potential and injury potential of different bullet types in the use of a newly developed bullet shooting stunner for adequate stunning of heavy cattle

Introduction

Recently, a special bullet shooting stunner for heavy cattle has been developed that fires a bullet instead of a bolt. In the search for a suitable ammunition, the following criteria must be met: First, the energy of the bullet must be sufficient to penetrate the thick frontal bones of heavy cattle. Second, the injury potential at the corresponding penetration depth should preferably be large in order to damage brain tissue relevant to stunning. Third, the bullet must not perforate the occipital bone (over-penetration).

Methods

Four different bullet types [Hornady FTX, Hydra-Shok, Black Mamba, and a common full metal jacket (FMJ) bullet] were evaluated in a series of experiments on soap blocks and removed bone plates followed by computed tomography examinations. Penetration potential was evaluated in terms of kinetic energy relative to the caliber of the bullet, i.e., mean energy density (ED). Injury potential was evaluated by the mean extent of the cavity volume (e _CV ) at the relevant penetration depth of 5.5 to 7.5 cm in the soap block.

Results

All four bullet types passed through the frontal bone plate. The ED was 17.50 J/mm² (Hornady FTX), 17.46 J/mm² (Hydra-Shok), 13.47 J/mm² (Black Mamba), and 13.47 J/mm² (FMJ). The Hornady FTX and the Hydra-Shok each fragmented heavily. The FMJ was excluded after three experiments due to over-penetrations. The e _CV was e _CV = 3.77 cm² (Hornady FTX), 2.71 cm² (Hydra-Shok), and 1.31 cm² (Black Mamba), with a significant difference (p = 0.006) between the Hornady FTX and the Black Mamba.

Discussion

For use in heavy cattle, the Hornady FTX and the Hydra-Shok are recommended due to the larger e _CV than the Black Mamba.