Evaluation of brainstem disruption following penetrating captive-bolt shot in isolated cattle heads: comparison of traditional and alternative shot-placement landmarks

Quantification of cooling effects on basic tissue measurements and exposed cross-sectional brain area of cadaver heads from Holstein cows > 30 mo of age

Penetrating captive bolt (PCB) is the primary method of preslaughter stunning for cattle and is also used for on-farm euthanasia. The objective of this study was to quantify the impact of cooling on the soft tissue thickness, cranial thickness, total tissue thickness, and cross-sectional brain area of cadaver heads collected from mature (> 30 mo of age) dairy cows following the application of a PCB stun in a frontal placement. Hide-on cadaver heads were obtained from culled dairy cows (N = 37) stunned in a frontal location using a handheld PCB device (Jarvis Model PAS-Type C 0.25R Caliber Captive Bolt, Long Bolt) at a commercial slaughter establishment. Following transport to the University of Wisconsin-River Falls, heads were split at midline along the bolt path by a bandsaw and then underwent FRESH, CHILL24, CHILL48, and CHILL72 refrigeration treatments. The FRESH treatment involved images collected immediately after splitting each head, the CHILL24 treatment involved images collected after 24 h of refrigeration, the CHIL48 treatment involved images collected after 48 h of refrigeration, and the CHILL72 treatment involved images collected after 72 h of refrigeration. Measurements of soft tissue thickness, cranial thickness, total tissue thickness, and cross-sectional brain area were recorded for each refrigeration treatment. Soft tissue thickness did not differ caudal to (P = 0.3751) or rostral to (P = 0.2555) the bolt path. Cranial thickness did not differ caudal to (P = 0.9281) or rostral to (P = 0.9051) the bolt path. Total tissue thickness did not differ caudal to (P = 0.9225; FRESH: 24.77 mm, CHILL24: 23.93 mm, CHILL48: 24.27 mm, CHILL72: 42.30, SE: 0.86) or rostral to (P = 0.8931; FRESH: 24.09 mm, CHILL24: 23.99, CHILL48: 24.26, CHILL72: 24.43 mm, SE: 0.79 mm) the bolt path. Cross-sectional brain area was not different (P = 0.0971) between refrigeration treatments (FRESH: 9,829.65 ± 163.87 mm2, CHILL24: 10,012.00 ± 163.87 mm2, CHILL48: 9,672.43 ± 163.87 mm2, CHILL72: 10,235.00 ± 166.34 mm2). This study demonstrated that FRESH tissue parameters can be determined from cattle cadaver heads refrigerated for 24, 48, or 72 h.

Assessment of United States Department of Agriculture Food Safety Inspection Service Humane Handling Enforcement Actions: 2018-2020

Federally inspected slaughter establishments in the United States must adhere to the Humane Methods of Slaughter Act and regulations that enforce it. Failure to comply with this law results in a Humane Handling Enforcement Action (HHEA) issued by the United States Department of Agriculture Food Safety Inspection Service (USDA FSIS). The objective of this study was to systematically analyze and describe HHEAs issued between 2018 and 2020. Enforcement action notification letters were accessed from the USDA FSIS website and date, location, regulatory action, reason for noncompliance, species, and follow up action for each HHEA was recorded. Summary statistics (proportions and percentages) were calculated for the entire population dataset. Between 2018 and 2020, FSIS issued 293 HHEAs; 109 in 2018, 85 in 2019, and 99 in 2020. The majority of HHEAs (64.16%; 188 of 293) were related to the mechanical stunning of bovine (39.93%; 117 of 293) and porcine (24.23%; 71 of 293) species. The majority (50.23%; 107 of 213) of causative reasons for mechanical stun failure across all species were not clearly described; however, of those that were, most (39.12%; 68 of 213) were related to the placement of mechanical stuns. Addressing these issues through improved training and research would help to reduce the total number of HHEAs. Additional detail in reporting the events that result in HHEAs from USDA FSIS would aid in guiding corrective actions on an industry-wide scale.

History and best practices of captive bolt euthanasia for swine

The definition of animal welfare includes how an animal dies. As such, euthanasia is intrinsically linked to animal welfare and ensuring a good death through effective, safe, and validated practices is a critical piece of promoting positive animal welfare. The objective of this review is to provide a better understanding of the literature on the euthanasia of swine via penetrating captive bolt (PCB) and nonpenetrating captive bolt (NPCB), as well as a history of captive bolt use, and indicators of sensibility and insensibility. To do this, we performed a systematic review that included 30 peer-reviewed articles and 17 other publications. Nonpenetrating captive bolt devices have been validated as an effective single-step euthanasia method for neonatal and pre-weaning swine, as well as a two-step euthanasia method for nursery swine. Penetrating captive bolt devices have been validated as an effective euthanasia method for nursery and market swine up to 120 kg, but further investigation is required for the use of captive bolt devices on mature breeding sows and boars.

Reduction of the occurrence of incorrect stunning and the occurrence of reflexes and reactions in cattle after pneumatically powered captive-bolt stunning in comparison with cartridge-fired captive-bolt stunning

In this study, the occurrence of repeat stunning, deviations in placement and direction of stun shots, and the occurrence of reflexes/reactions following stunning with a pneumatically powered captive-bolt stunner in comparison with a cartridge-fired captive-bolt stunner in cattle were assessed. Repeat stunning and deviations in placement and direction of the stun shots were less frequent (p < 0.01) with the use of a pneumatic stunner in all cattle. The rate of repeat stunning and deviation from the ideal place and direction of stun shots were lower (5.81%, 24.75%, and 9.60% of all animals, respectively) when a pneumatic stunner was used in comparison with cartridge-fired captive bolt (18.32%, 34.03%, and 47.38% of all animals, respectively). The stunning quality was assessed on the basis of evaluation of signs observed following the stun shot. A pneumatic stunning resulted in a significant reduction of occurrence of signs particularly in bulls in comparison to cows, for which a cartridge-fired stunner already provides an adequate stunning. Our study provides evidence that pneumatic stunning has the potential to be a more effective method than cartridge-fired stunning from the viewpoint of the welfare of slaughtered animals. Pneumatic stunning ensures a high quality of stunning in both bulls and cows.

Quantification of cooling effects on basic tissue measurements and exposed cross-sectional brain area of cadaver heads from market pigs

The objective of this project was to determine the impact of cooling on the soft tissue thickness, cranial thickness, and cross-sectional brain area of cadaver heads from market pigs. Documenting the effect of cooling on tissue dimensions of swine heads is valuable and important for future investigations of physical stunning and euthanasia methods that use cadaver heads. Scalded and dehaired cadaver heads with intact jowls were sourced from market pigs stunned with CO₂ gas. After transport to the data collection location, a penetrating captive bolt (PCB) shot (Jarvis Model PAS—Type P 0.25R Caliber Captive Bolt Pistol with Medium Rod Assembly and Blue Powder Cartridges) was applied in the frontal position. Following PCB application, each head (n = 36) underwent an UNCHILLED treatment followed by CHILLED treatment. The UNCHILLED treatment involved images collected immediately after splitting each head along the bolt path, and the CHILLED treatment involved images of the same heads after storage in a walk-in cooler for 24 h at 2 to 4°C. All measurements for each treatment were collected from images of the heads on the plane of the bolt path immediately prior to and immediately after the refrigeration treatment. Measurements were performed by two observers. Across all measurements, mean interobserver coefficient of variation was 11.3 ± 0.6%. The soft tissue caudal to the bolt path was different (P = 0.0120) between treatments (CHILLED: 6.4 ± 0.2 mm; UNCHILLED: 7.2 ± 0.2 mm). The soft tissue thickness rostral to the bolt path was different (P = 0.0378) between treatments (CHILLED: 5.5 ± 0.2 mm; UNCHILLED: 6.1 ± 0.2 mm). Cranial thickness caudal to the bolt path was not different (P = 0.8659; CHILLED: 18.1 ± 0.6 mm; UNCHILLED: 18.3 ± 0.6 mm), nor was there a significant difference (P = 0.2593) in cranial thickness rostral to the bolt path between treatments (CHILLED: 16.2 ± 0.6 mm; UNCHILLED: 15.2 ± 0.6 mm). Cross-sectional brain area did not differ (P = 0.0737; CHILLED: 3633.4 ± 44.1 mm; UNCHILLED: 3519.9 ± 44.1 mm). A correction factor of 1.12 was determined from this study for cases where estimation of UNCHILLED soft tissue thickness from CHILLED soft tissue thickness is necessary.

Gunpowder-powered captive bolts for the euthanasia of kangaroo pouch young

Euthanasia of macropod pouch young becomes necessary in situations when the mother has died as a result of situations such as: culling programs, vehicle collisions, bushfires, dog attacks, and entrapment in fences. Euthanasia methods currently recommended for older (furred) pouch young are contentious, hence the need to develop a more reliable method of euthanasia. To investigate animal welfare outcomes resulting from the use of a gunpowder-powered captive bolt, an independent veterinarian observed euthanasia of 28 furred kangaroo pouch young. Pouch removal duration was zero for all animals as the captive bolt was applied in situ in the pouch. Immediate insensibility was observed for 27 (96%) of the pouch young, exceeding the commonly used animal welfare standard of 95%. Results indicate that a gunpowder-powered captive bolt can produce favourable animal welfare outcomes for euthanasing kangaroo pouch young by delivering more than 40 times the kinetic energy delivered by previously studied captive bolt units applied to pouch young. When compared with other euthanasia methods for kangaroo pouch young, the use of a gunpowder-powered captive bolt delivers favourable animal welfare outcomes.

Euthanasia of Cattle: Practical Considerations and Application

Simple Summary

Methods recognized as acceptable for the euthanasia of cattle include overdose of an anesthetic, gunshot and captive bolt. The most common injectable anesthetic agent used for euthanasia is pentobarbital and while it may be the preferred method for euthanasia in sensitive situations, it creates significant challenges for disposal of animal remains. Gunshot and captive bolt are the more common methods used on farms and ranches because they are inexpensive, humane and do not complicate carcass disposal. Firearms must be of the proper caliber and loaded with the proper ammunition. Captive bolt, equipped with a penetrating bolt, is to be used on adult animals, whereas the non-penetrating (mushroom head) bolt should be reserved for use in calves (three months of age or less). In addition to selection of the proper firearm or captive bolt, successful euthanasia requires use of the proper anatomic site and adjunctive steps to assure death. The indicators of unconsciousness and death must be clearly understood and confirmed in all situations involving euthanasia. Tools for the efficient depopulation of a large feedlot, dairy or beef cattle operation as may be required in a national animal health emergency situation have been developed and validated as effective. Finally, the human impact of euthanasia cannot be underestimated. Symptoms of mental illness including depression, grief, sleeplessness and destructive behaviors including alcoholism and drug abuse are not uncommon for those who participate in the euthanasia of animals.

Abstract

Acceptable methods for the euthanasia of cattle include overdose of an anesthetic, gunshot and captive bolt. The use of anesthetics for euthanasia is costly and complicates carcass disposal. These issues can be avoided by use of a physical method such as gunshot or captive bolt; however, each requires that certain conditions be met to assure an immediate loss of consciousness and death. For example, the caliber of firearm and type of bullet are important considerations when gunshot is used. When captive bolt is used, a penetrating captive bolt loaded with the appropriate powder charge and accompanied by a follow up (adjunctive) step to assure death are required. The success of physical methods also requires careful selection of the anatomic site for entry of a “free bullet” or “bolt” in the case of penetrating captive bolt. Disease eradication plans for animal health emergencies necessitate methods of euthanasia that will facilitate rapid and efficient depopulation of animals while preserving their welfare to the greatest extent possible. A portable pneumatic captive bolt device has been developed and validated as effective for use in mass depopulation scenarios. Finally, while most tend to focus on the technical aspects of euthanasia, it is extremely important that no one forget the human cost for those who may be required to perform the task of euthanasia on a regular basis. Symptoms including depression, grief, sleeplessness and destructive behaviors including alcoholism and drug abuse are not uncommon for those who participate in the euthanasia of animals.