Penetrating Captive Bolt Research Articles

Relationship of tissue dimensions and stun placement on cadaver heads from 2-to-3-year-old male bison (Bison bison).

The bison industry in the United States has been growing rapidly. In 2023, over 75,000 bison were commercially slaughtered, but stunning methods for bison did not appear to be scientifically evaluated at the time of our study. Our primary objective was to evaluate tissue thicknesses at the frontal (FRONTAL: 2.5cm above a line connecting the bottom of the horns) and poll (POLL: below the crest of the head at the midline and angled toward the ventral aspect of the nose) placements in bison. Secondary objectives were to assess potential for bolt-thalamus contact and determine an optimal stunning placement based on thalamic location. Fifteen cadaver heads from 2- to 3-year-old bulls (HCW: 300.50 ± 27.42kg; mean ±SD) with hide-on were obtained from a commercial slaughter establishment after being stunned with a 0.410-bore shotgun at a frontal location. All heads were shaved, and external head features were measured. A 0.25R-caliber Jarvis free-flight penetrating captive bolt (PCB) was applied at the POLL placement. Heads were split at the midline and soft tissue and cranial thicknesses were measured with a digital caliper. Digital images were obtained of the split head to evaluate brain and thalamic contact plane. From these images, an IDEAL placement was determined to ensure bolt-thalamic contact. The IDEAL placement is in a significantly different (P < 0.0001) location than the FRONTAL placement and is located 8.33 ± 0.36cm above the base of the horns at the midline with the shot placed perpendicular to the surface of the head. For the IDEAL placement, the bolt path was in the plane of the thalamus for 14/14 heads (100.00%, 95% CI: 76.8 to 100.0%) while only in the plane of the thalamus at the FRONTAL placement for 11/14 heads (78.57%, 95% CI: 49.2 to 95.3%) and at the POLL placement for 10/14 heads (71.43%, 95% CI: 42.0 to 91.6%). Total tissue thickness was significantly greater (P < 0.0008) at the FRONTAL placement (75.00 ± 1.84mm; URL: 89.31mm) than the IDEAL (60.92 ± 1.90mm; URL: 70.64mm) and POLL (64.60 ± 1.84mm; URL: 85.52mm) placements. There was no evidence to support a difference (P = 0.5166) in total tissue thicknesses between the IDEAL and POLL placements. Thalamic depth at the IDEAL placement was 115.27 ± 8.36mm (URL: 133.96mm). Therefore, to consistently reach the thalamus and cause insensibility, it is recommended to stun at the IDEAL placement and have a penetration depth of at least 133.96mm for PCB use in young male bison.

Pathophysiology of Penetrating Captive Bolt Stunning in Horned and Polled Sheep and Factors Determining Incomplete Concussion.

Penetrating captive bolt (PCB) is widely used for stunning and on-farm dispatch of livestock, yet its efficacy can vary, with the potential for animal welfare compromise. This study investigated the pathophysiology of PCB-induced trauma in horned and polled sheep (Ovis aries), focusing on factors contributing to incomplete concussion. Thirty-seven (n = 18 horned Scottish blackface and n = 19 polled North Country mule) mature ewes (aged 4-10 years) were shot with PCB with varying cartridge power and PCB modifications, followed by clinical assessment and post-mortem analysis using magnetic resonance imagining (MRI) and gross pathology. The results indicated that damage to the reticular activating system, bolt velocity and penetration depth are crucial for inducing irreversible unconsciousness, with depths less than 37 mm often resulting in incomplete concussion. MRI provided detailed insights into brain injuries, aligning well with gross pathological findings. This study highlights the importance of precise bolt placement and appropriate PCB configurations in ensuring humane outcomes, with MRI proving to be a valuable tool for assessing brain trauma in stunned animals. These findings enhance the understanding of effective stunning techniques and support improved welfare practices in livestock management.

Clinical and electrocardiographic evidence of death following use of a poll shot with a penetrating captive bolt as a single-step method for euthanasia of cattle

The objective of this study was to validate the effectiveness of a penetrating captive bolt when positioned behind the poll as a single-step method for humane euthanasia of cattle. Seven­teen bovine animals of various ages (neonate to mature) that were eligible for euthanasia were enrolled in the study. Cattle were euthanized using a penetrating captive bolt gun with an extended bolt positioned flush against the parietal bone on midline just behind the poll and aimed toward the base of the tongue. Clinical and ECG parameters were monitored and recorded following application of the poll shot method. One animal required a second shot due to improper angle of the captive bolt device. All properly placed and aimed shots suc­cessfully induced immediate loss of consciousness without re­turn to sensibility which was followed by clinical death. Once unconscious, none of the cattle required a secondary step to assure clinical death. Following death, the head was removed, transected sagittally on midline, and brain trauma was as­sessed and scored. A properly placed and aimed poll shot was determined to be an effective single-step method of euthana­sia of cattle when using a penetrating captive bolt.

A preclinical model for osteoarticular fracture fragment preservation for delayed re-implantation

A preclinical model for osteoarticular fracture fragment preservation for delayed re-implantation

Evaluation of the capacity and effective angle of thalamic damage for 2 commercially available captive bolt tool types on cadaver heads from sows >200 kg body weight.

This study evaluated the ability of 2 penetrating captive bolt (PCB) types (PISTOL, INLINE) to reach and disrupt the thalamus when applied in 2 placements (FRONTAL, BEHIND EAR) to chilled cadaver heads (N = 60) from sows >200 kg. Heads were randomly distributed across 6 treatments (n = 10): FRONTAL-INLINE, FRONTAL-PISTOL, FRONTAL-NO SHOT, BEHIND EAR-INLINE, BEHIND EAR-PISTOL, and BEHIND EAR-NO SHOT. The FRONTAL shot was placed 3.5 cm superior to the optic orbits at the midline; the BEHIND EAR shot was placed directly caudal to the pinna of the ear on the same plane as the eyes and targeting the middle of the opposite eye. For INLINE treatments, a Jarvis PAS-Type C 0.25R Super Heavy Duty PCB with a Long Bolt and 6.0 GR power loads was used. For PISTOL treatments, a Jarvis PAS-Type P 0.25R Pistol PCB with a Long Stunning Rod Nosepiece Assembly and 3.5 GR power loads was used. Heads were split along the bolt with a band saw. Tissue depth measurements are reported as Mean ± SE followed by 97.5% one-sided upper reference limit (URL). Total tissue thickness was less (P < 0.0001) at the FRONTAL (56.31 ± 1.76 mm; URL: 73.17 mm) than the BEHIND EAR placement (95.52 ± 3.30 mm; URL: 126.53 mm). Thalamic depth was less (P < 0.0001) at the FRONTAL (78.31 ± 1.32 mm; URL: 88.19 mm) than the BEHIND EAR placement (111.86 ± 3.22 mm; URL: 135.99 mm). The effective angle was greater (P < 0.0001) at the FRONTAL (4.72 ± 0.20°) than the BEHIND EAR placement (3.22 ± 0.17°). Potential for bolt-brain contact was not different (P = 1.0000) between FRONTAL-INLINE (10/10, 100% ± 0.01%), FRONTAL-PISTOL (10/10, 100% ± 0.01%), BEHIND EAR-INLINE (9/10, 90% ± 9.49%), and BEHIND EAR-PISTOL (10/10, 100% ± 0.01%); brain damage (P = 0.5577) between FRONTAL-INLINE (9/9, 100% ± 0.02%), FRONTAL-PISTOL (10/10, 100% ± 0.02%), BEHIND EAR-INLINE (4/10, 40% ± 15.49%), and BEHIND EAR-PISTOL (1/10, 10% ± 9.49%); potential for bolt-thalamus contact (P = 0.0683) for FRONTAL-INLINE (2/10, 20% ± 12.65%), FRONTAL-PISTOL (8/10, 80% ± 12.65%), BEHIND EAR-INLINE (7/9, 77.78% ± 13.86%), and BEHIND EAR-PISTOL (9/9, 100% ± 0.02%); or thalamic damage (P = 0.8041) for FRONTAL-INLINE (1/10, 10% ± 9.49%), FRONTAL-PISTOL (1/10, 10% ± 9.49%), BEHIND EAR-INLINE (2/8, 25% ± 15.31%), and BEHIND EAR-PISTOL (0/9, 0% ± 0.00%). The FRONTAL placement with an INLINE PCB may present the least risk of failure for the PCB euthanasia of mature sows >200 kg body weight due to less total tissue thickness and thalamic depth, greater effective angle, and prevalent brain damage.

Validation of a poll shot captive bolt as a single step method of euthanasia of cattle

Euthanasia should occur with minimal pain and distress for the animal and the person administering the procedure. The AVMA Guidelines for Euthanasia lists a frontal shot as the recommended anatomical location for both penetrating cap­tive bolt and gunshot euthanasia. However, in many situations access to the frontal site is not possible or may cause exces­sive distress to the animal. The objective of this study was to validate the effectiveness of a penetrating captive bolt when positioned behind the poll as a single step method for humane euthanasia of cattle.

Description of tissue profiles, thalamic location, and recommended penetrating captive bolt placement in cadaver heads from domesticated 24- to 48-mo-old male yaks (Bos grunnians).

Yaks are a domesticated species utilized for meat, fiber, and transportation in many countries. In the United States, yak meat is growing in popularity due to its classification as a "healthy" meat. Penetrating captive bolt (PCB) is an approved method of preslaughter stunning and euthanasia for cattle. At the time of our study, peer-reviewed literature or industry guidelines for PCB stunning or euthanasia did not appear to exist for yaks. This study aimed to identify and describe an ideal placement based on the location of the thalamus, part of the brain that is important for sensibility, and to describe the tissue depths at this placement. To do this, 10 hide-on cadaver heads from yaks were sourced from a population of 30 yaks aged 24 to 48 mo, which had a mean hot carcass weight of 180.1 ± 52.0kg (±SD). Source animals were stunned in a frontal location with a handheld PCB during normal slaughter procedures at the collaborating slaughter establishment. Cadaver heads were stored in a walk-in freezer for 96 d before head processing. Head weight, total head length, horn tip spread, and horn base circumference were measured. Heads were split down the midline using a band saw. Heads were imaged and tissue thicknesses of the exposed surface of each head were measured. Thalamic depth and measurements to describe the location of the thalamus relative to external head anatomy were recorded from these images. Results are reported as mean ± SD. On average, the total length of the head from the poll to the nose was 37.74 ± 2.83cm. The center of the thalamus was located 11.86 ± 1.32cm below the poll: 23.88 ± 1.56% down the frontal plane of the head. The exposed diameter of the thalamus on the frontal plane of the head was 3.43 ± 0.31%. Thus, an ideal PCB placement for yaks is located approximately 25% of the way down the frontal plane of the face of the animal. Tissue depth measurements are reported as mean ± SD followed by a 97.5% one-sided upper reference limit (URL). Soft tissue thickness was 16.03 ± 3.26mm (URL: 23.77mm), cranial thickness was 30.69 ± 4.34mm (URL: 40.97mm), and total tissue thickness was 46.71 ± 7.15mm (URL: 63.68mm). Thalamic depth was 92.22 ± 11.60mm (URL: 119.74mm). These results show that an ideal PCB placement for yaks is located at 23.88 ± 1.56% of the distance from the poll to the nose down the frontal plane of the head and a penetration depth of 92.22 ± 11.60mm is required to reach the thalamus.

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 24h of refrigeration, the CHIL48 treatment involved images collected after 48h of refrigeration, and the CHILL72 treatment involved images collected after 72h 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: 24.77mm, CHILL24: 23.93mm, CHILL48: 24.27mm, CHILL72: 42.30, SE: 0.86) or rostral to (P = 0.8931; FRESH: 24.09mm, CHILL24: 23.99, CHILL48: 24.26, CHILL72: 24.43mm, SE: 0.79mm) the bolt path. Cross-sectional brain area was not different (P = 0.0971) between refrigeration treatments (FRESH: 9,829.65 ± 163.87mm2, CHILL24: 10,012.00 ± 163.87mm2, CHILL48: 9,672.43 ± 163.87mm2, CHILL72: 10,235.00 ± 166.34mm2). This study demonstrated that FRESH tissue parameters can be determined from cattle cadaver heads refrigerated for 24, 48, or 72h.

Assessment of time to death, brain tissue damage and clinical signs of consciousness in mature Jersey x Holstein cattle receiving a secondary penetrating captive bolt gunshot at the poll or frontal sinus locations

Providing cattle with a good death is an ethical imperative for the dairy industry. When using a penetrating captive bolt gun (PCBG), a secondary (adjunctive) method is currently recommended. Some farms prefer to apply the secondary shot in the poll location whereas others prefer the frontal-sinus location. Unfortunately, little is known about the efficacy of these alternative secondary shot locations. The purpose of this study was to compare clinical signs of consciousness and time to death for 2 different secondary PCBG shot locations in mature Jersey x Holstein cross dairy cattle. Data was collected contemporaneously at 6 dairy operations located in the Midwest U.S. After receiving the first PCBG shot in the frontal-sinus location, cattle requiring euthanasia (n = 46) were randomly assigned to receive a secondary PCBG shot in either the poll (Frontal- Poll) or the frontal-sinus location (Frontal-Frontal) and continuously monitored for clinical signs of consciousness (corneal and palpebral reflex, rhythmic breathing, threat response, etc.) and heartbeat. Signs of consciousness were rarely observed immediately following the first frontal-sinus shot. The median time period when the last heartbeat was heard (7-8 min) did not differ between groups (P = 0.253) nor did gross brain trauma scores (P = 0.247). We conclude the location of the secondary PCBG shot (frontal vs poll) does not seem to impact time to death or gross brain trauma scores. These findings confirm results of previous research involving younger cattle and suggest additional research is needed to better understand the effect of different PCBG locations.

Field Based Assessment of Clinical Signs of Irreversible Loss of Consciousness and Death Confirmed by Brain Destruction in Juvenile American Alligators (Alligator mississippiensis) After Penetrating Captive Bolt Stunning or Electrostunning with Probe Pithing

ABSTRACT To determine the humane use of slaughter methods we examined the clinical signs of life in 61 American alligators harvested on-farm using one of three methods: (i) captive bolt and spinal cord severance; (ii) electrostunning, spinal cord severance and pithing; and (iii) spinal cord severance and pithing. Loss of consciousness and the six clinical signs of life that can be used on-farm were assessed for evidence of irreversible unconsciousness and death at Time 0, 0.5, 1, 2, 5, 10, 20, and 30 min post slaughter. The brains of alligators from each slaughter method were removed to assess brain tissue disruption. A combination of loss of blink reflex, pupillary light response, jaw tone and respiration are a reliable on-farm tool for determining death. Heartbeat and withdrawal reflex persisted. Captive bolt and electrostunning methods were effective in immediately producing loss of response consistent with irreversible unconsciousness, subsequent death and destruction of neural tissue integrity in the mid and hind brain. They are therefore humane forms of slaughter in American alligators.

Highly Effective Frontal Stunning Procedure Using a Pneumatic Penetrating Captive Bolt in Water Buffaloes

An effective frontal stunning procedure in water buffaloes was assessed using a pneumatic penetrating captive bolt (PPCB) with high air pressure. The study contemplated two phases; first, 352 buffaloes and 168 post-mortem heads were evaluated to determine the most effective anatomical site for stunning. Then, the second phase (n = 182) was used to validate the stunning procedure at the discovered anatomical site in the first phase, which was located 8 cm dorsal above the middle of the forehead on an "X" formed between the eyes and the base of the contralateral horns, and 2 cm lateral, avoiding the midline, where the skull tended to narrow. A total of 95.1% of buffaloes received effective stunning at the first shot with evidence of the presence of collapse, absence of rhythmic breathing, and absence of ocular reflexes (corneal and palpebral). There were no differences in the stunning efficacy by sex, breed, or skull thickness. These findings demonstrated that stunning with a PPCB at pressures of 1379-1516.8 KPa (200-220 pounds per square inch (psi)) in the site reported here produces a highly effective stunning at the first shot in water buffaloes.

Evaluation of tissue depth, captive bolt penetration force and energy, and potential for bolt-thalamus contact in cadaver heads from physically castrated market barrows and immunocastrated boars.

The main objective of this study was to describe tissue thicknesses of cadaver heads from physically castrated market barrows (PC MARKET BARROWS) and immunocastrated boars (IC BOARS) at the frontal penetrating captive bolt (PCB) placement. Other objectives were to describe differences in bolt force and energy requirements to penetrate and describe potential for bolt-thalamus contact. Forty-four heads were obtained from PC MARKET BARROWS (n = 22) and IC BOARS (n = 22) of similar age and size that were rendered insensible with CO2. Mean HCW was 117.32 ± 3.52 kg. Snout to poll distance (cm) and maximum deflection distance (cm) were collected in duplicate. Heads were split at midline with a bandsaw and soft tissue and cranial thicknesses were measured with a digital caliper. Images of each cut surface were collected to evaluate the potential for thalamic damage. Tissue samples were retained from each half of each head and a universal tester was used to determine maximum force and energy of bolt penetration. There was no evidence to support a significant difference (P > 0.05) in tissue thicknesses between PC MARKET BARROWS and IC BOARS. Maximum deflection distance (maximum distance from a straight edge that was placed from the tip of the snout to the poll of the head) was not different (P = 0.10) between PC MARKET BARROWS (3.31 ± 0.10 cm) and IC BOARS (3.08 ± 0.10 cm). There was no evidence to support a difference (P = 0.77) in maximum force between PC MARKET BARROWS (7130.32 ± 483.23 N) and IC BOARS (6974.60 ± 463.70 N). There was also no evidence to support a difference (P = 0.62) in maximum energy between PC MARKET BARROWS (33.37 ± 2.77 J) and IC BOARS (32.04 ± 2.50 J). For PC MARKET BARROWS, there was a difference (P = 0.05) between the number of heads where the thalamus was located within the theoretical plane of bolt travel for market placement (21/21) versus mature placement (16/21). For IC BOARS, the number of heads where the thalamus was located within the plane of theoretical bolt path was not different between the two PCB placements (19/21 each). Overall, the data suggest that tissue profiles of PC MARKET BARROWS and IC BOARS do not differ at the frontal PCB placement site and the mechanical tools that are effective for PC MARKET BARROWS should also be effective for IC BOARS.

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. NPCB devices have been validated as an effective single-step euthanasia method for neonatal and preweaning swine, as well as a two-step euthanasia method for nursery swine. PCB 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.

Technical Note: Validation of the effectiveness of electric stunning for euthanasia of mature swine (Sus scrofa domesticus).

Electrocution and the use of a penetrating captive bolt gun (PCBG) are both acceptable methods of euthanasia for market weight swine. Research has demonstrated that a PCBG is effective in both growing and mature swine. Given limited to no published research base on electrocution in mature swine, the objectives of the present study were to evaluate the efficacy of a two-stage (head only followed by head to heart, 10s contact for each) mobile electric stunner (E-STUN, Hubert HAAS TBG 96N) and to assess euthanasia outcomes when comparing E-STUN with the frontal placement of a heavy-duty PCBG (Jarvis, In-line Cylinder Style) when applied to heavy-weight (>200kg) mature boars and sows. Effectiveness of the E-STUN and PCBG was evaluated first in unconscious anesthetized mature swine (n = 7 boars and sows per treatment; average weight 282±48kg, n = 28) to reduce the risk of failure in a conscious animal and then in conscious mature swine (n = 3 boars and sows per treatment; average weight 282±63kg, n = 12). Data from both stages were combined for analyses. Treatment efficacy was defined as any pig that achieved cardiac and respiratory arrest within 10min after treatment application. A three-point traumatic brain injury score (0 = normal; 1 = some abnormalities; and 2 = grossly abnormal, unrecognizable) was used to evaluate six neuroanatomical structures (cerebral cortex, cerebellum, hypothalamus, thalamus, pons, and brain stem), and the presence of intracranial hemorrhage was also noted. All animals were immediately rendered insensible with E-STUN and PCBG, and no difference was noted between treatments for the detection of corneal reflex following treatment application (P = 0.11). Rhythmic breathing was absent following the administration of either E-STUN or PCBG. When evaluating the time to last heartbeat, there was a significant interaction between sex and treatment. Boars euthanized via E-STUN had a 346.8-s decrease in time to last heartbeat compared with boars euthanized via PCBG (P < 0.001), and females euthanized via E-STUN had a 479.3-s decrease in time to last heartbeat compared with females euthanized via PCBG (P < 0.001). Intracranial hemorrhage was common for both methods, and visible disruption of neural tissue was evident due to the physical nature of the PCBG. This study demonstrated that a mobile E-STUN system is as effective as a heavy-duty PCBG in inducing insensibility and death and shows promise as an alternative method for euthanizing mature pigs on-farm.

Comparison of frontal-sinus and poll shot locations as secondary methods for euthanizing dairy cattle with a penetrating captive bolt gun

Humane euthanasia is a crucial component of dairy farm animal welfare programs. When using either a gunshot or captive bolt, the frontal-sinus area is well established as the primary shot location, but a secondary shot is often used as well. The objective of this study was to evaluate the efficacy of 2 different secondary shot locations. Cattle from a commercial dairy operation (n = 44) were randomly assigned to receive a secondary shot in the frontal-sinus or poll location and clinical signs of consciousness were assessed. A subsample of adult cattle heads (n = 6) were also evaluated to assess the extent of trauma. With the exception of heartbeat, all signs of sensibility were absent immediately following the first frontal-sinus shot and remained absent until confirmation of death, regardless of treatment (P &gt; 0.05). Relatively fewer animals shot in the poll location had a heartbeat 5 min after being shot (P = 0.03). Pathology results on the subsample of adult cattle showed poll shots rarely penetrated beyond the cerebrum and only 1 of 6 animals had a severed brainstem. We conclude the frontal-sinus and poll locations are similarly effective secondary shot locations, and brainstem damage may not be necessary for irreversible insensibility and death.

Relationship of tissue dimensions and three captive bolt placements on cadaver heads from mature swine (Sus scrofa domesticus) > 200 kg body weight.

Three penetrating captive bolt (PCB) placements were tested on cadaver heads from swine with estimated body weight (BW) >200 kg (sows = 232.9 ± 4.1 kg; boars = 229.3 ± 2.6 kg). The objectives were to determine tissue depth, cross-sectional brain area, visible brain damage (BD), regions of BD, and bolt-brain contact; and determine relationships between external head dimensions and tissue depth at each placement. A Jarvis PAS-Type P 0.25R PCB with a Long Stunning Rod Nosepiece Assembly and 3.5 g power loads was used at the following placements on heads from 111 sows and 46 boars after storage at 2 to 4 °C for ~62 h before treatment: FRONTAL (F)-3.5 cm superior to the optic orbits at midline, TEMPORAL (T)-at the depression posterior to the lateral canthus of the eye within the plane between the lateral canthus and the base of the ear, or BEHIND EAR (BE)-directly caudal to the pinna of the ear on the same plane as the eyes and targeting the middle of the opposite eye. For sows, the bolt path was in the plane of the brain for 42/42 (100%, 95% confidence interval [CI]: 91.6% to 100.0%) F heads, 39/40 (97.5%, 95% CI: 86.8% to 99.9%) T heads, and 34/39 (87.5%, 95% CI: 72.6% to 95.7%) BE heads; for the heads that could reliably be assessed for BD damage was detected in 25/26 (96.2%, 95% CI: 80.4% to 99.9%) F heads, 24/35 (68.6%, 95% CI: 50.7% to 83.2%) T heads, and 5/40 (12.5%, 95% CI: 4.2% to 26.8%) BE heads. For boars, the bolt path was in the plane of the brain for 17/17 (100.0%, 95% CI: 80.5% to 100.0%) F heads, 18/18 (100.0%, 95% CI: 81.5% to 100.0%) T heads, and 14/14 (100.0%, 95% CI: 76.8% to 100.0%) BE heads; damage was detected in 11/12 (91.7%, 95% CI: 61.5% to 99.8%) F heads, 2/15 (13.3%, 95% CI: 1.7% to 40.5%) T heads, and 7/14 (50.0%, 95% CI: 23.0% to 77.0%) BE heads. Tissue depth was reported as mean ± standard error followed by 95% one-sided upper reference limit (URL). For sows, total tissue thickness was different (P < 0.05) between placements (F: 52.7 ± 1.0 mm, URL: 64.1 mm; T: 69.8 ± 1.4 mm, URL: 83.9 mm; BE: 89.3 ± 1.5 mm, URL: 103.4 mm). In boars, total tissue thickness was different (P < 0.05) between placements (F: 41.2 ± 2.1 mm, URL: 56.3 mm; T: 73.2 ± 1.5 mm, URL: 83.4 mm; BE: 90.9 ± 3.5 mm, URL: 113.5 mm). For swine > 200 kg BW, F placement may be more effective than T or BE due to less soft tissue thickness, which may reduce concussive force. The brain was within the plane of bolt travel for 100% of F heads with BD for 96.2% and 91.7% of F sow and boar heads, respectively.

Comparison of penetrating and non-penetrating captive bolt in an alternative occipital approach in calves

AbstractThe objective of this study was to describe the effect of penetrating or non-penetrating captive bolt using an occipital approach in 4-5 month old, Holstein steers weighing between 100-200 kg. Twelve calves were divided into two treatment groups; penetrating captive bolt (PCB; n = 6) and non-penetrating captive bolt (NPCB; n = 6). This sample size was chosen out of convenience and in conjunction with a separate study. Each calf was sedated with xylazine hydrochloride, then a captive-bolt device, outfitted with a standard penetrating bolt or a non-penetrating bolt, was placed flush on the dorsal midline of the cranium at the external occipital protuberance and aimed downward as though to intersect the intermandibular area. Following impact, indicators for loss of consciousness, such as respiration, righting response, corneal reflex, movement and vocalisation were recorded and characterised along with electrocardiogram and electroencephalogram recordings. After a 5-min observation period, all calves were administered potassium chloride. All calves experienced immediate and sustained loss of consciousness. The mean (± SEM) time to cessation of respiration was 60 (± 53.67) and 0 (± 0.0) s for PCB and NPCB, respectively. The mean time to cessation of convulsions was 310.4 (± 79.74) and 180.0 (± 60.24) s, respectively, and the mean number of convulsions was 2.75 (± 1.03) and 2.0 (± 0.837) for PCB and NPCB, respectively. Isoelectric EEG patterns were observed in 3/5 PCB and 3/4 NPCB with mean time to onset of isoelectric pattern in 69.0 (±52.24) and 113.5 (± 56.87) s. Both treatments induced a successful stun, which suggests these techniques are appropriate for humane euthanasia in calves of this age.

PSIII-16 Evaluating the impact of group stunning on physiological parameters of pigs in a small abattoir

Abstract Small abattoirs commonly process pigs and sheep in a handling system designed for cattle. Smaller species are usually stunned in groups in the cattle shackling area in front of the stun box. The purpose of this study was to determine the effects of stun order on physiological parameters in pigs. A total of 148 barrows and gilts were stunned in 29 groups of four to five pigs with seven control pigs. All pigs were moved together into the stunning pen and stunned one at a time with a handheld penetrating captive bolt stunner and immediately shackled and processed. The average time from pen entrance to the final stun was 22 minutes. To act as a control, one pig was moved into the pen individually and stunned after the same elapsed time as the groups. Blood lactate and glucose concentration were measured in exsanguination blood using hand-held analyzers. A one-way ANOVA was used to determine the effect of stun order on blood metabolite concentration. Pigs stunned first had significantly greater lactate than the last pigs stunned (P &amp;lt; 0.01). Stun order did not have a significant effect on blood glucose concentration (P = 0.43). The control pigs had significantly lower lactate than the first pig stunned (P = 0.04). Greater blood lactate concentrations in the first pig may be due to handling into the stunning pen prior to the first stun. Handler interaction may have resulted in an increase in certain behaviors such as turning back and squealing which further caused the first pigs to have increased lactate.

Macroscopic Examination of Multiple-Shot Cattle Heads-An Animal Welfare Due Diligence Tool for Abattoirs Using Penetrating Captive Bolt Devices?

Simple SummaryThe most common method of stunning cattle prior to bleeding in an abattoir is a penetrating captive bolt device, which is basically a piston driven forward by expanding gas produced by a blank cartridge. This creates a concussed state in the animal on impact with the skull, followed by penetration to prevent recovery by destroying key parts of the brain. The successful application of this device requires the correct cartridge strength for the species and accurate placement of the device. This paper examines the heads of animals that have received multiple shots in an attempt to ascertain the cause, to provide abattoirs with training material and an investigative tool to reduce the occurrences of multiple shots and reduce the consequent negative effects on animal welfare at slaughter.Ideally, the application of a penetrating captive bolt device to render cattle immediately unconscious prior to slaughter would be 100% effective. Unfortunately, due to various factors this is not always the case. This paper examined, as an initial proof of concept, 12 bovine heads which had received more than one shot from a penetrating captive bolt, collected from various abattoirs within the United Kingdom. The heads were frozen to facilitate splitting on the medial plane to prevent distortion of soft tissue and each sagittal section was examined macroscopically to ascertain if this method could be used to determine the reasons for repeated stun attempts. In 10 out of 12 heads, shot placement was the determining factor, in one other head it was felt that anatomical variation was the reason and the twelfth head demonstrated signs of gun malfunction as the likely cause. This work provides evidence for a larger trial to facilitate the production of guidance for the abattoir industry, the Animal Welfare Officer and regulators on the examination of heads as part of an investigation of failures of a mechanical stunning system and to provide training material for slaughter staff tasked with effectively stunning cattle.

The effects of bolt length on penetration hole characteristics, brain damage and specified-risk material dispersal in finished cattle stunned with a penetrating captive bolt stunner

The effects of bolt length on penetration hole characteristics, brain damage and specified-risk material dispersal in finished cattle stunned with a penetrating captive bolt stunner