Captive Bolt Gun Research Articles

Evaluation of non-penetrative captive bolt stunning as a method of slaughter for white sturgeon (Acipenser transmontanus)

IntroductionPercussive stunning is a widely used and ethically supported method of stunning fish per welfare standards as part of a one- or two-step slaughter process. In this study, the use of a non-penetrative captive bolt (NPCB) gun was evaluated as an effective one-step method of improving welfare for juvenile and adult farmed white sturgeon (Acipenser transmontanus) at slaughter.MethodsA Jarvis HPS-1 NPCB was operated at pressures of 120, 135, and 145 PSI (827.37, 930.79, and 999.74 kPa, respectively) for juvenile sturgeon (n = 3 sturgeon per operating pressure) and 175, 200, and 225 PSI (1206.58, 1378.95, and 1551.32 kPa, respectively) for adult sturgeon (n = 3 sturgeon per operating pressure). Following a single strike, fish were assessed for jaw relaxation and a somatic response before being exsanguinated and transferred to an ice slurry. An hour after slaughter, fish heads were collected, and a section of cartilage containing the brain was removed and fixed in formalin for histological analysis of brain death. To evaluate fish recovery, juveniles (n = 100) and adult female sturgeon (n = 65) were monitored for two hoursafter a single exposure to 145 and 225 PSI, respectively.ResultsHistology results showed there was an effect between operating pressure and intracranial hemorrhage in juvenile sturgeon (p = 0.024). There was a greater meningeal-to-cerebral hemorrhage at 135 PSI compared to the 120 PSI group (p = 0.020) and a trend towards increased tissue damage from 120 PSI to 145 PSI (p = 0.056). Adults showed no significant difference in meningeal hemorrhage at any operating pressure. When investigating recovery rates, NPCB successfully stunned 100% of juvenile sturgeon at 145 PSI, and 225 PSI stunned 90% of adult sturgeon without recovery.DiscussionThese results demonstrate that the use of an NPCB gun is an improvement in animal welfare compared to repeated strikes, but a single application did not produce histological brain death; further research should be conducted to determine optimal pressures that result in immediate brain death.

Captive Bolt Gun-Related Vascular Injury: A Single Center Experience.

This article investigates the clinical and radiological characteristics of captive bolt gun head injuries, a rare form of low-velocity penetrating brain injury. Eleven consecutive patients were included in the study. Vascular injuries and the rate of infection were systematically analyzed. Radiological findings reveal common bolt trajectories in the anterior cranial fossa, with identified risk factors for a poor outcome including trajectory crossing midline, hematocephalus, and paranasal sinus involvement. Only one patient had a good outcome. Despite meticulous microsurgical techniques, this study highlights often unfavorable clinical outcomes in captive bolt gun injuries, with vascular injury identified as a potential contributing risk factor for a poor outcome. Knowledge of variant vascular tree anatomy and corresponding vascular territory is important. To avoid potential vascular injuries, a complete removal of bone fragments was not always performed and it did not increase the rate of infection, challenging the conventional wisdom advocating for the complete removal of bone fragments. These findings contribute novel insights into captive bolt gun-related injuries, paving the way for further research.

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.

A decade on: where is the UK poultry industry for emergency on-farm killing?

Millions of poultry are farmed intensively every year across the United Kingdom (UK) to produce both meat and eggs. There are inevitable situations that require birds to be emergency killed on farm to alleviate pain and suffering. In Europe and the UK, emergency methods are regulated by the European Council Regulation (EC) No. 1099/2009 and The Welfare of Animals at the Time of Killing Regulations (England 2015; Scotland 2012; Wales and Northern Ireland 2014). Cervical dislocation has been reported to be the most widely used method prior to these legislative changes which took place from 1 January 2013. Based on limited scientific evidence and concern for bird welfare, these legislative changes incorporated restrictions based on bird weight for both manual (≤3 kg) and mechanical (≤5 kg) cervical dislocation, and introduced an upper limit in the number of applications for manual cervical dislocation (up to 70 birds per person per day). Furthermore, it removed methods which showed evidence of crushing injury to the neck. However, since legal reform new scientific evidence surrounding the welfare consequences of cervical dislocation and the development of novel methods for killing poultry in small numbers on farm have become available. Whether the UK poultry industry have adopted these novel methods, and whether legislative reform resulted in a change in the use of cervical dislocation in the UK remains unknown. Responses from 215 respondents working across the UK poultry industry were obtained. Despite legal reform, manual cervical dislocation remains the most prevalent method used across the UK for killing poultry on farm (used by 100% of farms) and remains the preferred method amongst respondents (81.9%). The use of alternative methods such as Livetec Nex® and captive bolt guns were available to less than half of individuals and were not frequently employed for broilers and laying hens. Our data suggests there is a lack of a clear alternative to manual cervical dislocation for individuals working with larger species and a lack of gold standard methodology. This risks bird welfare at killing and contributes to inconsistency across the industry. We suggest providing stakeholders with practical alternatives prior to imposing legislative changes and effective knowledge transfer between the scientific community and stakeholders to promote positive change and protect bird welfare.

Preslaughter stress and beef quality in relation to slaughter transport of cattle

Preslaughter handling inevitably exposes cattle to stress, which affects beef quality and yields. Short transports to the slaughterhouse or a short walk across the yard to a mobile abattoir parked on the farm may reduce stress, with potential beneficial effects on meat quality. To compare different road transport distances to a stationary (fixed) slaughterhouse, and the stationary plant with a mobile abattoir, we studied commercial slaughter of 298 cattle in each facility over a period of 13 months. For the stationary slaughterhouse, the estimated transport distance from farm to plant was 7–250 km (mean 99 km) and 96 animals spent one night in lairage there. All animals at both slaughterhouses were stunned with a captive bolt gun. Blood levels of cortisol, glucose and lactate at exsanguination and meat quality indicators were recorded. According to two-sample t-tests, thawing loss was 1 percent unit lower (p<0.0001), Warner-Bratzler shear force was 6.9 N lower (p<0.0001) and compressive load was 3.9 MPa lower (p<0.0001), but mean lactate level was 1.02 mmol/l higher (p<0.0001) and ultimate pH was 0.05 units higher (p=0.0001) in the mobile facility compared with the stationary. Effects of slaughter facility and estimated road transport distance to the stationary plant on blood lactate, ultimate meat pH, shear force and compressive load were analysed by generalized linear mixed models, with delivering farm as random effect. According to the models, predicted shear force was 23% higher at the 95th percentile of the transport distance compared with the 5th percentile (p=0.012), and there was some evidence of a similar difference in compressive load for heifers, albeit only marginally significant (39% higher at the 95th percentile; p=0.056). Predicted blood lactate was 19% higher in the mobile abattoir than the stationary slaughterhouse (p=0.046). Ultimate meat pH was higher in the mobile unit for cows and steers (p≤0.0020), and for carcasses weighing 311–380 kg (p≤0.0020). Compressive load was 27% lower in the mobile abattoir, compared to the stationary (p<0.0001), but shear force did not differ significantly between the two facilities. This study shows a negative effect of long transport distances on beef tenderness. It also provides evidence of differences in beef quality between a mobile abattoir and a stationary slaughterhouse, although these differences may be attributable to specific routines for carcass handling and ageing at the studied facilities, and not the transport and slaughter strategy itself.

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.

FFP maintains normal coagulation while Kcentra induces a hypercoagulable state in a porcine model of pulmonary contusion and hemorrhagic shock.

Moderate injury can lead to a coagulopathy. Fresh frozen plasma (FFP) corrects coagulopathy by means of a balanced array of clotting factors. We sought to compare the late effects of FFP and a prothrombin complex concentrate (PCC) on the coagulopathy of trauma using a porcine model of pulmonary contusion (PC) and hemorrhagic shock (HS) designed to evaluate the organ protective effects of these treatments. Female Yorkshire swine (40-50 kg) were randomized to receive PC + HS or control (instrumented and uninjured). A blunt PC was created using a captive bolt gun. To induce HS, a liver crush injury was performed. Eighty minutes after injury, swine were treated with 25 U·kg-1 PCC, 1 U FFP, or 50 mL lactated Ringer's vehicle in a blinded manner. Arterial blood samples were drawn every 6 hours. Swine were euthanized 48 hours postinjury. Data were analyzed by Pearson χ2, analysis of variance and Kruskal-Wallis tests with Tukey's or Mann-Whitney U tests for post hoc analysis. Twenty-seven swine received PC + HS, 3 groups of 9 per group received PCC, FFP, or vehicle. Nine were noninjured controls. When compared with control, PC + HS swine had significantly shortened R time at 6 hours, 36 hours, and 42 hours, decreased LY30 at 12 hours, shortened K time at 30 hours and reduced α angle at 42 hours. PC + HS swine showed significant differences between treatment groups in K and α angle at 3 hours, LY30 at 12 hours and 18 hours, and MA at 12 hours, 18 hours, and 30 hours. Post hoc analysis was significant for higher α angle in PCC versus vehicle at 3 hours, higher MA in vehicle versus PCC at 12 hours and 18 hours, and higher LY30 in PCC versus vehicle at 18 hours (p < 0.012) with no significant differences between FFP and vehicle. Severe injury with HS induced a coagulopathy in swine. While FFP maintained normal coagulation following injury, PCC induced more rapid initial clot propagation in injured animals.

Assessing the effectiveness of percussive and electrical stunning in rainbow trout: Does an epileptic-like seizure imply brain failure?

Both percussive and electrical stunning have been highlighted as methods that can be used to quickly render fish unconscious before being killed. However, accurately assessing unconsciousness in animals following stunning remains challenging, and thus methods for reliable interpretation and validation of different stunning methods are urgently needed. Here, we used a non-invasive technique to continuously record electroencephalograms (EEG) of rainbow trout (Oncorhynchus mykiss) enabling us to compare the effects of both percussive stunning, using a captive bolt gun, and various combinations of electrical stun parameters delivered in water. The EEG signals were assessed for the absence or presence of an epileptic-like seizure and for visually evoked responses (VERs). No epileptic-like seizures or VERs were observed after captive bolt stunning. We found that it is possible to reliably induce an epileptic-like seizure and an immediate, but short lasting, loss of VERs following a 1 s exposure to an electrical field strength of at least 2.8 VRMS cm−1 and current density of 0.22 ARMS dm−2 in water of conductivity of ~1000 μS cm−1 using a 50 Hz AC current. However, to avoid recovery of VERs shortly after the stun, it was necessary to increase the duration of the stun application (≥30 s), the electrical field strength (10.2 VRMS cm−1) and the current density (0.84 ARMS dm−2 respectively). We found no clear relationship between presence and absence of ventilation and VERs following electrical stunning in rainbow trout, highlighting that loss of ventilation may not be a good indicator of brain failure in rainbow trout. Our results clearly show that the presence of an epileptic-like seizure following an electrical stun does not guarantee a prolonged period where the fish is unresponsive to visual stimulation (i.e. absence of VERs). It was further found that VERs can return before the end of the seizure. As both presence of a seizure and absence of VERs have been used independently as indicators of unconsciousness in fish, we emphasize the necessity to carefully consider and evaluate the reliability of neurophysiological indicators of unconsciousness when validating methods to stun fish.

Rupture of the Superior Sagittal Sinus in Penetrating Head Injury-Management of a Rare Trauma Mechanism.

Civilian penetrating head injury caused by foreign objects is rare in Germany (Europe), but can result in complex neurovascular damage. We report on a patient who in suicidal intent inflicted on himself a penetrating brain injury near the vertex with a captive bolt gun. A laceration at the junction of the middle to the posterior third of the superior sinus occurred by bolt and bone fragments leading to critical stenosis and subsequent thrombosis. Upon surgery, the proximal and distal sinus openings were completely thrombosed. The sinus laceration was closed by suture and the intraparenchymal bone fragments were retrieved. Postoperative angiography disclosed persistent occlusion of the superior sagittal sinus. The patient did not develop any symptoms due to venous congestion (edema, hemorrhage), suggesting sufficient collateral venous outflow. The patient completely recovered despite the complexity of the lesion.

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.

Religious slaughtering: Implications on pH and temperature of bovine carcasses

The main objective of this study was to investigate the influence of different types of slaughtering on the variations of pH and temperature. Ninety entire male beef cattle, belonging to the Charolais breed, were distributed in three groups based on method of slaughtering. A total of 30 subjects (group K) were slaughtered without stunning, according to the Koscher rite; thirty bovines (group T) were stunned with a captive bolt gun, following the common slaughtering reported by Council Regulation (EC) 1099/2009; other thirty animals (group H) were slaughtered without stunning, based on Halal procedures. The temperature and pH values of carcasses were determined at 3, 6 and 24 h post-mortem, respectively. At 24 h post-mortem of the 30 carcasses evaluated for each group, muscle temperature decreased in all three types of slaughtering. In particular, the average temperature was 4.0, 4.9 and 3.0 °C for traditional, Halal and Koscher slaughtering, respectively. Moreover, at the same time step (24 h post-mortem), muscle pH decreased showing values equal to 5.72, 5.83, 5.81 for traditional, Halal and Koscher slaughtering, respectively. The findings of the present study may be useful to highlight the influence of slaughtering method on pH and, more generally, on meat quality. Additionally, our results show that, in slaughtering carried out without prior stunning, the carcass could be more susceptible to alterations because of the high pH values.

283 Timely Euthanasia on Farm; Dairy Cattle and Swine

Abstract Euthanasia of mature swine and cattle can be challenging. On-farm euthanasia should be used as a tool to eliminate pain and suffering. However, clear guidelines regarding making euthanasia decisions and alternative euthanasia techniques available for use is limited in the United States (US). In order to prevent prolonged suffering and pain in compromised animals, science-based recommendations are needed to ensure timely and humane euthanasia can be performed when needed on-farm. This presentation will focus on two euthanasia challenges currently faced in swine and dairy cattle systems in the US today: 1) Swine: Validating alternative euthanasia techniques for use in mature breeding stock and 2) Dairy Cattle: Identifying producer barriers preventing timely euthanasia decision-making using surveys and focus groups. The swine study evaluated the effectiveness of two penetrating captive bolt gun styles (cylinder or pistol) using a frontal, temporal and behind-the-ear placement. Four treatments were 100% effective in achieving cardiac arrest and death. The cylinder style captive bolt gun resulted in greater brain trauma and death compared to a pistol style gun and behind-the-ear and temporal placement showed promise as an alternative placement site for euthanizing mature pigs. In the dairy cattle study, dairy producers were recruited to participate in a survey and focus group. Survey results indicated that farm owners were most commonly responsible for on-farm euthanasia and most respondents would treat and monitor compromised cattle for a majority of health conditions, regardless of condition severity. Participants in focus groups focused primarily on animal welfare as the most important factor influencing the decision to euthanize and the desire to eliminate animal suffering by using euthanasia as a tool. This work highlights the complicated challenges that arise when euthanizing livestock and the importance of not only identifying appropriate techniques to humanely euthanize livestock but address the emotional and animal welfare factors that influence these decisions.

Validating the effectiveness of alternative euthanasia techniques using penetrating captive bolt guns in mature swine (Sus scrofa domesticus).

Euthanasia of mature swine is challenging. Temporal and behind-the-ear locations are two sites that have been identified as alternatives to the more commonly used frontal placement. In stage one, the effectiveness of two penetrating captive bolt gun styles (cylinder or pistol) was evaluated using frontal, temporal, and behind-the-ear placement in anesthetized mature swine (n = 36; weight: 267 ± 41 kg). For stage one, when evaluating treatment efficacy by sex, the cylinder-style equipment was 100% effective in achieving death when applied to all cranial locations (frontal, temporal, and behind-the-ear) for sows; however, the pistol-style equipment was only 100% effective when applied at the behind-the-ear location for sows. For boars, the cylinder-style equipment was 100% effective when applied to the frontal and behind-the-ear location, but the pistol-style equipment was not effective for any cranial location in boars. Therefore, the pistol-frontal, pistol-temporal, pistol-behind-the-ear, and cylinder-temporal were not included for boars, and pistol-frontal and pistol-temporal were not included for sows in stage two. In stage two, commercial, mixed-breed, mature swine (n = 42; weight: 292 +/- 56 kg) were randomly assigned to one of four treatments based on the inclusion criteria described in stage one. A three-point traumatic brain injury (TBI) score (0 = normal; 1 = some abnormalities; 2 = grossly abnormal, unrecognizable) was used to evaluate six neuroanatomical structures (cerebral cortex, cerebellum, hypothalamus, thalamus, pons, and brain stem), and the presence of hemorrhage was also noted. All treatments were 100% effective in stage two. A significant interaction between gun style and placement was determined on predicting total TBI as the cylinder style produced a higher total TBI score compared with the pistol type of the magnitude of +2.8 (P < 0.01). The cylinder style tended to produce a greater TBI score than the pistol in the temporal location (+1.2; P = 0.08). No difference was noted for TBI score behind-the-ear between the cylinder- and pistol-style gun (P > 0.05). TBI tended to be less in boars compared with sows (-0.6; P = 0.08). Hemorrhage was observed in frontal, parietal, occipital, and temporal lobes. This study demonstrated that the cylinder-style captive bolt gun more effectively resulted in brain trauma and death compared with a pistol-style gun and the behind-the-ear and temporal placement showed promise as an alternative placement site for euthanizing mature pigs on-farm.

Effects of penetrating captive bolt gun model and number of stuns on stunning-related variables of cattle in a commercial slaughter facility

The objective of this study was to assess two different penetrating captive bolt gun models (Jarvis USSS-1 and USSS-21) and two stunning methods (1KNOCK and 2KNOCK, applying one and two knocks, respectively) on stunning-related variables in cattle. Heads were collected at a commercial slaughter facility and knocking efficiency, knock hole diameter, brain damage, knock hole placement and hemorrhage were assessed. Knocking efficiency was not impacted by gun model or number of knocks (P = .39 and .12, respectively). Knock number influenced knock hole diameter, brain damage and hemorrhage in the cavity (P ≤ .01). Presence of brainstem damage was greater (P < .01) when using the USSS-21 gun. Results suggested similar performance between the USSS-1 and USSS-21 gun models. Potential benefits of using the newest model could be related to damaging vital brain areas like the brainstem.

Evaluation of physical euthanasia for neonatal piglets on-farm.

Twenty-seven neonate piglets (range from 0.35 to 1.17 kg) were evaluated for the effectiveness of blunt force trauma as a method of on-farm cull. Brainstem function, brain injury, and hemorrhage scores (increasing from 0 to 3) were assessed after striking the head against a concrete floor. Electroencephalograms (EEG) from a subset of 15 piglets were recorded before and after blunt force trauma for electrophysiological assessments. Blunt force trauma was performed by a single experienced farmer in a commercial farm by holding the piglet by its both hind legs and striking the head against the concrete floor. All piglets remained recumbent and did not show brainstem reflexes. Only one piglet did not presented tonic/clonic physical activity. The mean time to the onset of persistent isoelectric EEG was 64.3 ± 7.3 s (range 18 to 115). Total power, theta, alpha, and beta power decreased to approximately 45%, 30%, 20%, and 15% from pretreatment power, respectively, by 15-s post-impact. There were no periods of normal-like EEG after the culling. Bruises in the neck and shoulder were found in 67% and 70% of piglets, respectively. All piglets presented skull fractures with 20% having the nasal bone(s) fractured. Brain damage was found in all piglets, mainly in the frontal lobe(s). The occipital lobe(s) presented the greatest frequency of severe damage. The analysis of the radiographs also found a high frequency of fractures in this region. Hemorrhage was most frequent in the frontal, parietal, occipital lobes, and midbrain. When performed correctly with the appropriate weight class, blunt force trauma can be used as an effective method for the on-farm killing of nursing piglets resulting in death. However, this method should not be promoted over more reliable and repeatable cull methods such as captive bolt gun. As with blunt force trauma, there is a significant potential for animal welfare harm associated with inappropriate practice, lack of accuracy, issues with repeatability, and operator fatigue.

The punched-out tissue complex (skin-bone\xa0\u201dimprimatum\u201c) in shots from captive-bolt guns: does it act as a secondary projectile?

From the first half of the twentieth century to the present day, injuries and fatalities from captive-bolt livestock stunners are a major topic in forensic medicine. The vast majority of cases account for suicides with the frontal, temporal, parietal, and occipital regions being the most common sites of entrance (in descending order of frequency). Due to the limited length of the bolt, the corresponding wound channel within the braincase is only several centimeters long. It has been a controversial subject for a long time, whether the skin-bone complex punched out by the conically grooved end of the steel rod may act as a “secondary projectile” being propelled beyond the actual path of the bolt. To answer this question, experimental shots from various types of captive bolt-guns were fired to simulants. Video-documentation employing a high-speed motion camera showed that the punched-out pieces of skin and bone did not move further than the bolt. Thus, a secondary extension of the total wound channel could not be observed. However, the suction effect caused by the bolt’s rearward movement may induce a slight retrograde displacement of the skin-bone complex.

The occurrence of reflexes and reactions in cattle following stunning with a captive bolt at the slaughterhouse.

The difference in the frequency of the occurrence of reflexes/reactions in 355 cows (average weight 505.5±7.9kg) and 262 bulls (average weight 735.6±8.4kg) following stunning with a Matador SS 3,000 B trigger-activated captive bolt gun (Termet) was determined. The stun shot more than 2cm from the ideal position was found in 79.6% of animals. Vocalization, corneal reflex, rhythmic breathing, blinking, eyeball rotation and the absence of tongue protrusion occurred more frequently in bulls (p<.05). Spontaneous limb movements and nystagmus occurred more frequently in cows (p<.05). No difference between bulls and cows was determined in the occurrence of a response to painful stimuli or attempts to regain normal posture. No dependency was determined between the frequency of the occurrence of a reflex/reaction and the distance of the stun shot from the ideal point on the skull for any of the monitored signs. This study shows that the occurrence of reflexes/reactions following the stunning of cattle with a captive bolt is not only dependent on the position of the shot if placed within a 9cm radius from the ideal point on the cattle skull.

The Effect of Heat Stress on Autophagy and Apoptosis of Rumen, Abomasum, Duodenum, Liver and Kidney Cells in Calves.

Simple SummaryHeat stress causes significant negative responses in the dairy industry. The objective of this study was to assess the effect of heat stress on the autophagy and apoptosis of the rumen, abomasum, duodenum, liver and kidney in calves. The results showed that heat stress could increase the autophagy and apoptosis of the kidney, duodenum and abomasum. However, heat stress had no effect on the autophagy and apoptosis of the liver. In cows, most studies of autophagy and apoptosis have only focused on mammary remodeling. Our results provide new knowledge regarding autophagy and autophagy in calf heat stress management.The objective of this study was to assess the effect of heat stress on the autophagy and apoptosis of the rumen, abomasum, duodenum, liver and kidney in calves. Two groups of Holstein male calves were selected with similar birth weights and health conditions. Heat stress (HT): Six calves (birth weight 42.2 ± 2.3) were raised from July 15 to August 19. Cooling (CL): Six calves (birth weight 41.5 ± 3.1 kg) were raised from April 10 to May 15. All the calves were euthanized following captive bolt gun stunning at 35 d of age. The expression of protein 1 light chain 3-Ⅱ (LC3-Ⅱ) and caspase3 in the rumen, abomasum, duodenum, liver and kidney were determined by western blotting. In addition, other possible relevant serum biochemical parameters were evaluated. Significant differences were observed in alkaline phosphatase (ALP), albumin (ALB) and glucose (Glu). The results showed that heat stress could increase the autophagy and apoptosis of the kidney, duodenum and abomasum. However, heat stress had no effect on the autophagy and apoptosis of the liver. Additionally, the expression of caspase-3 in the rumen in HT was significantly lower than that in CL. In conclusion, the effects of heat stress on autophagy and apoptosis are organ-specific. The results provide knowledge regarding autophagy and autophagy in calf heat stress management.

Effect of captive bolt gun length on brain trauma and post-stunning hind limb activity in finished cattle Bos taurus

Hind limb post stunning kicking in properly stunned unconscious cattle is a safety hazard for employees. Three different captive bolt lengths of 15.2 cm (STRD), 16.5 cm (MED), and 17.8 cm (LON) were evaluated for amount of tissue damage and hind limb kicking in a Jarvis USSS-1 pneumatic stunner. The air pressure setting was 1378.95 to 1447.90 pKa for all captive bolts. All 45 test cattle were rendered unconscious with a single shot. There was a trend (P = .06) for less kicking to occur when the 16.5 cm length bolt was used in the stunner. Visual appraisal of the brains on the split heads indicated that the shortest bolt caused the least amount of brain damage. The brainstems were intact for all cattle regardless of captive bolt treatment. Young fed English, Continental European, and Holstein steers and heifers can be effectively stunned without visible brainstem disruption.

Effectiveness of pneumatically powered penetrating and non-penetrating captive bolts in stunning cattle

This study assessed the effectiveness of penetrating (PCB; 190 psi; N = 363) and non-penetrating captive bolt guns (NPCB; 210–220 psi; N = 92) to stun a total of 455 cattle (Zebu and Zebu Cross). Physical bolt parameters (momentum, kinetic energy and energy density) were evaluated. Clinical indicators of brain function were recorded after stunning (GR), after being hoisted (HO) and at the bleeding rail (BL). Physical bolt parameters (bolt velocity, momentum, kinetic energy, energy density and sectional density) were significantly higher (P < 0.001) for PCB. The need for two or more shots was more frequent for NPCB (210–220 psi; 29% vs. 12%, P < 0.001). Cattle were more likely to collapse at first shot with PCB (190 psi; 99%) compared to NPCB (91%; P < 0.002) which can be attributed to the higher values of bolt physical parameters. Incidence of eyeball rotation (5% vs. 1%) and righting behaviour (7% vs. 1%) were higher (P < 0.001) for NPCB (210–220 psi) at GR than PCB. The NPCB with 210–220 psi had a higher frequency of response to nostril stimulation (2% vs. 0%; P < 0.001) than PCB. Rhythmic respiration was more frequently found for NPCB with 210–220 psi at GR, HO and BL. Therefore, PCB with 190 psi was more effective in ensuring unconsciousness in cattle.