Assessment of stun quality at commercial slaughter in cattle shot with captive bolt

The use of a penetrative captive bolt device during the killing of farmed saltwater crocodiles (Crocodylus porosus)

Killing of farmed saltwater crocodiles involve stunning with a penetrative captive bolt device, followed by a cut across the nape of the neck and physical destruction of the brain to ensure death. This study was a welfare-based assessment of the use of a penetrative captive bolt device in saltwater crocodiles, to determine whether it satisfies the criteria of a humane stunning method and can be regarded as a direct killing method without the need for the application of an adjunct method. Methods used were electroencephalogram (EEG), observation of post-stun behavior, and postmortem examination of gross pathology of the cranium and brain. 30 of 30 animals, demonstrated immediate and irreversible loss of consciousness. There was extensive damage to the brain in all animals, deemed to be inconsistent with cortical function and possible recovery. The CASH Special 0.22 penetrative captive bolt pistol (1.25 grain cartridge), applied to the top of the cranial plate, produced immediate and irreversible unconsciousness in all the animals studied. This method satisfies animal welfare expectations, providing crocodile processors with a technique that contributes to a humane killing process.

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.

Slaughtering of Water Buffalo (Bubalus bubalis) with and without Stunning: A Focus on the Neurobiology of Pain, Hyperalgesia, and Sensitization

The slaughter process in livestock is considered a stressor where the transport and handling of animals, as well as the selected stunning and bleeding methods, can cause acute pain, distress, and suffering. In water buffaloes, although stunning is known to be performed before bleeding to induce unconsciousness, no emphasis is made on the nociceptive events during this process. Particularly, current mechanical stunning methods applied to cattle are unsuitable for water buffaloes due to anatomical differences in the skull from other large ruminants. Furthermore, although very high-pressure pneumatic (200-220 psi) may be effective in the frontal position for lighter-weight water buffalos, for heavier animals, it is less likely to be effective. The present review aims: (1) to analyze the anatomical particularities of water buffaloes to discuss the importance of selecting a stunning method suitable for buffaloes, and (2) to revise the potential pain-related consequences, such as hyperalgesia and sensitization, and the signs to assess the stun quality and death to comprehend the relevance of a proper technique according to the species.

Impact of Social Buffering and Restraint on Welfare Indicators during UK Commercial Horse Slaughter

Current legislation in the United Kingdom stipulates that horses should not be slaughtered within sight of one another. However, abattoir personnel anecdotally report that, for semi-feral horses unused to restraint, co-slaughtering alongside a conspecific could reduce distress through social buffering and improve safety, but there is a lack of evidence to support this. CCTV footage from an English abattoir was assessed retrospectively with welfare indicators from when horses entered the kill pen until they were killed. Of 256 horses analysed, 12% (32/256) were co-slaughtered (alongside a conspecific) and 88% (224/256) individually. Co-slaughtered horses moved more in the pen, but individually slaughtered horses showed more agitated behaviour, required more encouragement to enter the kill pen, and experienced more slips or falls. Unrestrained horses (40%; 102/256) showed increased agitation, movement, and agonistic behaviour towards the operator and resisted entry to the kill pen compared to restrained horses (60%; 154/256). Positive interactions between conspecifics were seen in 94% (30/32) of co-slaughtered horses, and only 6% (1/16) showed a startled response to the first horse being shot, with a median time of 15 s between shots. This study highlights the impact that both conspecific and human interactions can have on equine welfare at slaughter. Semi-feral or unrestrained horses appear to experience increased distress compared to horses more familiar with human handling, and the presence of a conspecific at slaughter mitigated this.

Refinement of water-based foam depopulation procedures for finisher pigs during field conditions: Welfare implications and logistical aspects

Water-based foam (WBF) depopulation is currently being researched as an alternative for rapid destruction of swine populations under emergency circumstances. Appropriate guidelines are needed to maintain method reliability and depopulation efficacy while minimizing animal distress under field conditions. Finisher pigs were depopulated using WBF with a 7.5-minute dwell time in two trials to evaluate the effect of; trial 1) foam fill level (1.5, 1.75, or 2.0 times the pig's head height) and trial 2) foam fill rate (slow, medium, or fast) on aversive pig responses (surface breaks, vocalization, and escape attempts) and time to cessation of cardiac activity. Activity and cardiac activity were recorded using subcutaneous bio-loggers for swine in trial 2. The average time to cessation of movement (COM) from the start of foam filling was compared for the foam fill rate groups using a generalized linear mixed effect model under Poisson distribution. Foam rate group was used as an independent variable, and replicates as a random effect. For trial 1, the average (mm:ss ± SD) time to fill completion was 01:18 ± 00:00, 00:47 ± 00:05, and 00:54 ± 00:05, for 1.5, 1.75, and 2.0 times the pig's head height, respectively. For trial 2, the average time to fill completion was 03:57 ± 00:32, 01:14 ± 00:23 and 00:44 ± 00:03, and the average time (mm:ss ± SE) to COM was 05:22 ± 00:21, 03:32 ± 00:14, and 03:11 ± 00:13 for slow, medium, and fast fill rate groups, respectively. A higher number of aversive pig responses were observed for the lowest foam fill level and slowest foam fill rate compared to increased fill levels and faster fill rates. For trial 2 the median (mm:ss ± IQR) time to fatal arrhythmia was 09:53 ± 02:48, 11:19 ± 04:04, and 10:57 ± 00:47 post-foam initiation for fast, medium, and slow foam rate groups, respectively. Time to cessation of cardiac activity was significantly shorter for the fast foam rate group compared to medium and slow foam rates groups (P = 0.04). For both trials, vocalizations were absent, and all pigs were unconscious following the 7.5-minute dwell time and no pigs needed a secondary euthanasia method. This WBF study showed that slower fill rates and low foam fill levels may extend the time until cessation of cardiac activity in swine during depopulation. A conservative recommendation with consideration of swine welfare during an emergency scenario would be a minimum foam fill level twice the pig's head height and a foam fill rate capable of covering pigs in foam within 60 s to minimize aversive responses and expedite cessation of cardiac activity.

Animal Welfare during Transport and Slaughter of Cattle: A Systematic Review of Studies in the European Legal Framework

Literature related to European transport and slaughter processes were included in this systematic review. The publication period is limited to the past twelve years since the European Animal Welfare Transport Regulation was enacted in 2009. Three different databases were used. The final screening resulted in the inclusion of 19 articles in this review. When handling cattle during transport and slaughter, personnel have an important impact and may inflict stress on the animals. Other factors, such as the group composition and health status prior to transport, can have a strong negative effect on animal welfare. At the abattoir, constructional conditions and the resulting environmental influences can have a negative impact on welfare as well. These include increased noise levels due to the lack of noise dampening and changing light conditions. Stress in cattle can be assessed, e.g., by measuring stress hormones or heart rate. Effective stunning is an important welfare-relevant step in the slaughtering process. Some signs of unconsciousness, such as immediate body collapse or absence of the corneal reflex, can be easily assessed. Expertise and continuous training of all personnel involved are important measures in stress reduction.

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.

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.

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.

Animal Welfare and Food Safety When Slaughtering Cattle Using the Gunshot Method

Simple Summary

Transporting cattle from the farm to the slaughterhouse is often stressful for the animal. With the gunshot method, it is stunned using a rifle while together with familiar herd members in an enclosure on the farm. The shot makes the animal unconscious. Then, as in normal slaughter, the animal is bled to death. Finally, it is transported to a nearby slaughterhouse. We aimed to assess the consequences for animal welfare and food safety of using the gunshot method. Twenty Hereford steers were shot with a hunting rifle using small-calibre ammunition from an elevated position and distance of 6–12 m. Each time, only one out of four to seven animals in a 16 × 10 m corral was shot. Based on the animals’ behaviour and physiological blood values, stress levels before shooting were low. Eleven animals were considered completely unconscious, while seven showed some signs of consciousness and two were poorly stunned. Two animals were reshot with heavier ammunition. Bleeding was satisfactory and little or no contamination was found on the carcasses. We conclude that the gunshot method is applicable to large beef steers while maintaining a satisfactory level of animal welfare and food safety, provided that the necessary conditions can be achieved.

Abstract

Transporting cattle from farm to slaughterhouse is often stressful for the animal, which can impair the meat quality. With the gunshot method, the animal is stunned with a rifle shot while together with familiar herd members in their home environment, exsanguinated and transported to a nearby slaughterhouse. Aiming to assess the consequences for animal welfare and food safety, 20 Hereford steers aged 18–54 months were shot with .22 Magnum ammunition from an elevated position and distance of 6–12 m. Each time, only one out of four to seven animals in a 16 × 10 m corral was shot. Dressing was done on farm. Based on the animals’ behaviour and blood concentrations of cortisol, glucose and lactate, stress levels before shooting were low. Eleven animals were deeply stunned, the consciousness of seven others was ambiguous, and two were poorly stunned. Two animals were reshot. The bleed-out was satisfactory for all animals, and little or no faecal contamination was found on the carcasses. We conclude that the gunshot method is applicable to large beef steers while maintaining a satisfactory level of animal welfare and food safety, provided that the necessary conditions can be attained.

The effect of slaughtering skills on the welfare of cattle during stunning with a captive bolt

The performance of stunning in various abattoirs can differ. The aim of the study was to compare the stunning of cattle with a captive bolt in two abattoirs. We monitored the slaughtering skills by measuring the deviation of the location of the stunning shot hole on the skull from the ideal point and further by measuring the angle of inclination of the stunning shot on the skull from the ideal perpendicular angle. We observed the impact of different slaughter skills on the quality of stunning of animals based on the occurrence of failure to achieve motor paralysis after a stun shot. The failure to collapse occurred significantly more frequently (P < 0.05) in abattoir A than in abattoir B. In both abattoirs there was a higher (P < 0.05) number of bulls failing to collapse than in females (cows and heifers). However, the effect of slaughter skills on the occurrence of signs associated with insufficient stunning was not found. The signs occurred in abattoir A and abattoir B to the same extent. In bulls, the number of animals with signs was higher (P < 0.05) than in females in both abattoirs. The results show that insufficient proficiency of skills in stunning cattle with a captive bolt leads to a higher number of animals failing to collapse after a stun shot. The effect of slaughter skills on the occurrence of signs in bulls and females was not proven; however, in bulls a higher incidence of signs was demonstrated than in females.

Pain at the Slaughterhouse in Ruminants with a Focus on the Neurobiology of Sensitisation

Simple Summary

We pose based on a fundamental science examination that events that occur around the time of slaughter have the potential to intensify the pain response, through a process called sensitisation, or an exaggerated response to painful stimuli. Health conditions which result in inflammation, injuries arising from transport and handling and exaggerated fear responses may all be present at the slaughterhouse. Whilst there is limited evidence of a direct effect of these on the processes of sensitisation in animals at slaughter, by analogy with the human neurobiology literature the connection seems plausible. In this review we outline the biology of such a response, and the rationale for suggestion of a possible linkage between events at slaughter and a heightened animal pain response.

Abstract

We pose, based on a neurobiological examination, that events that occur around the time of slaughter have the potential to intensify the pain response, through the processes of sensitisation and enhanced transmission. Sensitisation, or an enhanced response to painful stimuli, is a well-discussed phenomenon in the human medical literature, which can arise from previous injury to an area, inflammatory reactions, or previous overstimulation of the stress axes. A number of events that occur prior to arrival at, or in the slaughterhouse, may lead to presence of these factors. This includes previous on-farm pathology, injuries arising from transport and handling and lack of habituation to humans. Whilst there is limited evidence of a direct effect of these on the processes of sensitisation in animals at slaughter, by analogy with the human neurobiology literature the connection seems plausible. In this review a neurobiological approach is taken to discuss this hypothesis in the light of basic science, and extrapolations from existing literature on the slaughter of ruminants. To confirm the postulated link between events at slaughter, and processes of hypersensitisation, further dedicated study is required.

A Case of Multiple Stun Attempts in a Bovine Due to Chronic Disease Process Causing Cranial Abnormalities

Simple Summary

Cattle that are to be processed for human consumption are routinely and legally rendered unconscious, to ensure that they cannot feel any pain, before the process of bleeding to cause brain death. The main method used in abattoirs is pneumatic or cartridge-powered captive bolt devices, which deliver a high velocity impact to the skull creating a severe concussion (stun). The penetrating captive bolts then continue travelling into the brain to prevent recovery from the stunned state by damaging the structures in the brain that are required for normal brain function. If this method does not work there is an obvious potential for the welfare of the animal to be compromised, so investigations are undertaken to establish the cause of any failures to reduce the risk of reoccurrence. This paper presents the results of such an investigation, where the cause of the failure of the device to stun was found to be due to the anatomy of the individual animal’s head. This unfortunate occurrence is rare but must be considered in any investigation of multiple stun attempts.

Abstract

The preslaughter stunning of bovine animals is a legal requirement in the European Union, unless the animal is being slaughtered according to religious rite. The legislation also requires the investigation and review of stunning methods in cases of failure to stun. This paper presents the results of one investigation into the possible reasons for multiple stun attempts on an animal that received five shot applications. The head was hard frozen to prevent the deformation of brain structures during splitting along the sagittal plane, and then underwent macroscopic examination to assess the likely causes of the repeated stun attempts. In this case, a pre-existing chronic disease process produced anatomical variations of the cranial cavity, increasing the thickness of the sinuses of the frontal bone to a depth of 9 cm and filling the sinuses with a fibrinous pus deposit. It was therefore concluded that the anatomical variation produced by the chronic disease process, in addition to the energy absorption provided by the thicker hide and fibrinous pus, led to the failure of the stunning equipment to achieve the desired stunned state in the animal. As the animal displayed cranial variation before slaughter, a review of the stunning systems should include a requirement that animals displaying any abnormalities should be stunned with the highest-powered cartridge available or a free bullet.

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 ± 7.9 kg) and 262 bulls (average weight 735.6 ± 8.4 kg) following stunning with a Matador SS 3,000 B trigger-activated captive bolt gun (Termet) was determined. The stun shot more than 2 cm 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 9 cm radius from the ideal point on the cattle skull.

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.

Animal welfare in the U.S. slaughter industry-a focus on fed cattle

Animal welfare within the U.S. slaughter industry continues to prevail as one of the top priorities for livestock producers, businesses, and consumers alike. There are federal regulations that enforce the humane transport, handling, and slaughter of cattle. The journey that cattle must make to the slaughter facility is comprised of many environmental and human factors that can positively or negatively affect animal welfare. Cattle may be exposed to multiple stressors, such as noise, unfamiliar animals and humans, temperature extremes, temporary food/water deprivation, variable transport distances and experiences, and new pen conditions. The animal caretakers involved in these processes attempt to minimize stress and discomfort for the animals, but research is needed to focus on the gaps in knowledge and to support the implementation of strategies known to enhance the human-animal interactions that occur from farm to slaughter. This literature review will provide a summary of fed cattle welfare topics, research, and industry tools that span across the beef animal's journey from the farm/feedlot through the slaughter process. In addition, areas that have had little research focus are identified to highlight the need for future work and development of industry tools. Some of these topics include examining trailer design, the use of trailer slats during weather extremes, the welfare aspects of cattle destined for salvage slaughter, multiple preslaughter factors and interactions, abnormal mobility and nonambulatory cattle, lairage environmental conditions, new stunning methods, and the impact of a well-trained, motivated, and stable workforce on cattle and people welfare. The authors conducted a survey at the 2019 North American Meat Institute Animal Care and Handling Conference, which comprised of stakeholders within the meat packing industry, packing plant employees, and food company employees, educators, and auditors. The survey responses identified training/education and communication as areas of need in animal welfare, whereas the majority of survey responses focused on the aspects of the human-animal interaction as the top challenges for the industry. By continuously identifying, measuring, monitoring, and managing animal welfare challenges within the beef cattle slaughter industry, prioritization and execution of programs and training that improve the welfare of cattle can be achieved as animals move through this final stage of the meat production system.

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 (p < 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.

An Examination of the Performance of Blank Cartridges Used in Captive Bolt Devices for the Pre-Slaughter Stunning and Euthanasia of Animals

Blank cartridges provide the power source for the majority of captive bolt devices used for rendering animals unconscious prior to slaughter within the United Kingdom or euthanasia worldwide. This paper presents the results of the examination of cartridges as one of the variables that can contribute to an unsuccessful application of this method in practice. Variation was found in cartridge weight, propellant fill volume and velocity within boxes of 1000 cartridges. The variation found was greater in lower charge (1.00 grain) cartridges than in 3.00 grain cartridges, however velocity was found to be variable in both sets. For example, in vivo velocity measurements with 0.25″ calibre 3.00 grain cartridges demonstrated an average velocity of 50.8 m/s over 200 shots with a range of 35.7 to 62.9 m/s when used in the same device. This work demonstrates that variation in cartridge performance does occur and can be due to various factors such as fill volume and propellant function, and simply weighing cartridges cannot be used to determine function, therefore cartridge performance must be a factor that is considered in the event of a miss-stun.

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

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 purpose of this study was to determine the effect of captive bolt lengths on penetration hole characteristics, brain damage, and specified risk material (SRM) dispersal. Cattle were stunned with a pneumatic captive bolt stunner using: standard (15.2 cm; STRD), medium (16.5 cm; MED), or long (17.8 cm; LON) bolts. Heads (N = 293) and exsanguination blood (N = 103) were collected for analyses. Penetration hole diameter and depth differed by treatment (P ≤ 0.004); both parameters were greatest for LON (P < 0.05). Presence of damage in frontal, parietal, and occipital lobes, olfactory bulb, and collective area including the corpus callosum, fornix and thalamus were impacted by treatment (P < 0.003). Treatment did not impact SRM dispersal (P = 0.33), determined by presence of glial acidic fibrillary protein. Data suggest that bolt length affects both the extent of brain damage and the specific structures damaged but all bolt lengths are successful in causing substantial brain damage and subsequent insensibility.

Electroencephalographic assessment of pneumatically powered penetrating and non-penetrating captive-bolt stunning of bulls

The electroencephalographic (EEG) responses of 31 bulls (zebu crossbred cattle) stunned with either pneumatically powered Jarvis penetrating (PCB) or non-penetrating captive bolt (NPCB) was examined. Animals were organized into two treatment groups: PCB (n = 20); and NPCB (n = 11) stunning, both using airline pressures of 220 psi (1517 kPa). All bulls shot with PCB (n = 20/20) had patterns of EEG activity that were inconsistent with consciousness. Of the cattle shot with NPCB 82% (n = 9/11) showed waveforms suggesting complete unconsciousness. After stunning two NPCB bulls had periods of normal EEG activity and maintenance (Ptot, delta, theta, beta) or increased (alpha) spectral power compared to pre-treatment values, indicating incomplete concussion. The study showed that pneumatic PCB stunning was effective in rendering all bulls unconscious, while NPCB was less effective. This highlights the potential animal welfare risks associated with NPCB compared to PCB stunning of mature bulls in commercial abattoirs.

Pre-slaughter cattle welfare indicators for use in commercial abattoirs with voluntary monitoring systems: A systematic review

Animal welfare has become an important subject of public, economic and political concern, leading to the need to validate indicators that are feasible to use at abattoirs. A systematic review was carried out, which identified 72 cattle welfare indicators (CWI) that were classified into four categories (physiological, morphometric, behavioral and meat quality). Their validity and feasibility for use in abattoirs were evaluated as potential measures of cattle welfare during transportation to the abattoir and at the abattoir itself. Several highly valid indicators were identified that are useful to assess welfare at abattoirs, including body condition score, human-animal interactions, vocalizations, falling, carcass bruising, and meat pH. In addition, some intermediate valid indicators are useful and should be investigated further. Information along the food chain could be used systematically to provide a basis for a more-risk-based meat inspection. An integrated system based on the use of key indicators defined for each inspection step with the setting of alarm thresholds could be implemented.

Efficiency of low versus high airline pressure in stunning cattle with a pneumatically powered penetrating captive bolt gun

The efficiency of stunning cattle was assessed in 443 animals (304 pure Zebu and 139 crossbred cattle), being mainly mature bulls and cows. Cattle were stunned using a Jarvis pneumatically powered penetrating captive bolt gun operating with low (160-175psi, N=82) and high (190psi, N=363) airline pressure, which was within the manufactures specifications. Signs of brain function and the position of the shots on the heads were recorded after stunning. Velocity of the captive bolt and its physical parameters were calculated. Cattle shot with low pressures showed more rhythmic respiration (27 vs. 8%, P<0.001), less tongue protrusion (4 vs. 12%, P=0.03) and less masseter relaxation (22 vs. 48%, P<0.001). There was an increased frequency of shots in the ideal position when cattle were shot with the low compared to high airline pressures (15.3 vs. 3.1%). Bolt velocity and its physical parameters were significantly (P<0.01) higher when using high pressure. Airline pressures below 190psi are inappropriate when shooting adult Zebu beef cattle with pneumatically powered penetrating captive bolt guns.

Comparison of penetrating and nonpenetrating captive bolt methods in horned goats

OBJECTIVE To use MRI and CT to compare the amount of tissue damage (soft tissue and bone) to the heads of goats after administration of a nonpenetrating or penetrating captive bolt. ANIMALS Cadavers of twelve 1- to 5-year-old mixed-breed goats that had been euthanized with an overdose of pentobarbital as part of an unrelated study. PROCEDURES Cadavers were randomly assigned to receive a nonpenetrating (n = 6) or penetrating (6) captive bolt. The head of 1 cadaver was imaged via CT and MRI. The muzzle of a device designed to administer either a penetrating or nonpenetrating captive bolt was then placed flush on the dorsal midline of each head at the level of the external occipital protuberance (poll) and aimed downward toward the cranialmost portion of the intermandibular space, and the assigned bolt was administered. Heads were removed, and CT and MRI of each head were performed. After imaging, each skull was transected along the sagittal plane to permit gross evaluation of central nervous tissue and obtain digital photographic images. In addition, 1 head that received a nonpenetrating captive bolt was further evaluated via blunt dissection and removal of adnexa from the external surface of the calvarium. RESULTS MRI, CT, and dissection of skulls revealed severe skeletal and soft tissue damage after impact with the penetrating and nonpenetrating captive bolts. CONCLUSIONS AND CLINICAL RELEVANCE The nonpenetrating captive bolt appeared to cause damage similar to that of the penetrating captive bolt in the cranium and soft tissues of the head in caprine cadavers. This damage suggested that administration of a nonpenetrating captive bolt as described here may be an acceptable method of euthanasia in goats.

Conventional versus modern abattoirs in Colombia: Impacts on welfare indicators and risk factors for high muscle pH in commercial Zebu young bulls

The aim of the study was to determine the effects of abattoir type (conventional abattoir -CA- versus modern abattoir -MA-) on stress parameters and risk factors for high muscle pH in Colombia. A total of 522 Zebu young bulls were studied in two groups: 285 at CA, and 237 at MA. Blood samples were taken to measure cortisol, glucose, lactate, creatine kinase, β-hydroxybutyrate, total protein, albumin, creatinine, urea, haematocrit, leukocytes and N/L ratio. Cattle were monitored during the unloading, lairage, handling and stunning. The logistic regression model showed that stocking density, transport time, abattoir type, and inefficient stunning were variables associated with the prevalence of dark cutting carcasses. This study demonstrated that modern improvements at abattoir level, proper infrastructure, and stunning equipment, do not always guarantee quality in terms of animal welfare. As a first attempt in the Colombian beef industry, this research suggested how handling practices could affect cattle welfare and the prevalence of high muscle pH even at MA.

Consciousness, unconsciousness and death in the context of slaughter. Part II. Evaluation methods

This second review describes indicators of consciousness and unconsciousness that can be used in the abattoir. These indicators evaluate different aspects of cerebral functioning, but only indirectly. It is therefore necessary to monitor several indicators. Animals are considered unconscious if signs of consciousness are absent, and signs of unconsciousness are present. Given that the unconscious state may be reversible it is further necessary to monitor these indicators until the end of bleeding. The techniques used to diagnose brain death in humans cannot be used in the slaughterhouse. Under field conditions, at the end of bleeding, the absence of breathing and of brainstem reflexes and the adequacy of the exsanguination are verified. If these three aspects are confirmed, in the context of the slaughterhouse and at this stage of the slaughter process the loss of vital functions is irreversible and the animal can be considered dead.

Magnetic resonance imaging and computer tomography of brain lesions in water buffaloes and cattle stunned with handguns or captive bolts

Owing to the demand for genuine mozzarella, some 330 water buffaloes are being slaughtered every year in Switzerland albeit a stunning procedure meeting animal welfare and occupational safety requirements remains to be established. To provide a basis for improvements, we sized anatomical specifics in water buffaloes and cattle and we assessed brain lesions after stunning with captive bolts or handguns by diagnostic imaging. In water buffaloes and cattle, the median distance from the frontal skin surface to the inner bone table was 74.0mm (56.0-100.0mm) vs 36.6mm (29.3-44.3mm) and from skin to the thalamus 144.8mm (117.1-172.0mm) vs 102.0 (101.0-121.0mm), respectively. Consequently, customary captive bolt stunners may be inadequate. Free bullets are potentially suitable for stunning buffaloes but involve occupational safety hazards. The results of the present study shall be used to develop a device allowing effective and safe stunning of water buffaloes.

Pathophysiology of penetrating captive bolt stunning in Alpacas (Vicugna pacos)

The aim of this study was to examine the behavioural and cranial/spinal responses of alpacas culled by captive bolt shooting and the resulting pathophysiology of captive bolt injury. Ninety-six alpacas were shot (103 shots) in a range of locations with a penetrating captive bolt gun (CBG). Ten (9.8%) alpacas were incompletely concussed following the first shot. No animals required more than two shots. Incorrectly placed shots accounted for all of the animals that displayed signs of sensibility. Damage to the thalamus, hypothalamus, midbrain, medulla, cerebellum, parietal and occipital lobes were significantly associated with decreasing odds of incomplete concussion. In conclusion, the study confirmed that CBG stunning can induce insensibility in alpacas and suggests that the top of the head (crown) position maximises damage to structures of the thalamus and brainstem.

Pathophysiology of free-bullet slaughter of horses and ponies

Forty-six equines were observed during routine commercial slaughter in an abattoir. The animals were shot once with a .22 calibre long rifle with hollow point rounds. Indicators of sensibility/insensibility were evaluated immediately after the shot (prior to exsanguination) and the resulting pathophysiology of free-bullet injury was assessed. All animals were rendered immediately insensible, with only one pony showing signs of a shallow depth of concussion, with an intermittently positive palpebral reflex but no other signs of brainstem function. All animals (100%) had some degree of damage to the structures of the brainstem or lobes of the cerebrums, while 41 (89%) had damage to the thalamus/hypothalamus. The bullet in one pony missed the brain but still caused mild damage to the thalamus, midbrain, pons and cerebellum, this animal had no signs of sensibility. The findings confirm that free-bullet shooting is an effective dispatch method for horses and ponies.

Factors affecting penetrating captive bolt gun performance

Captive bolt stunning is used for rendering livestock insensible at slaughter. The mechanical factors relating to performance of 6 penetrating captive bolt gun (CBG) models were examined. The Matador Super Sécurit 3000 and the .25 Cash Euro Stunner had the highest kinetic energy values (443 J and 412 J, respectively) of the CBGs tested. Ninety percent (27/30) of CBGs held at a government gun repository (United Kingdom) were found to have performed at a normal standard for the model, while 53% (10/19) of commercial contractor CBGs tested were found to underperform for the gun model. When the .22 Cash Special was fired 500 times at 4 shots per min, the gun reached a peak temperature of 88.8°C after 2.05 hr. Repeat firing during extended periods significantly reduced the performance of the CBG. When deciding on the appropriate CBG/cartridge combination, the kinetic energy delivered to the head of the nonhuman animal, bolt penetration depth, and species/animal type must be considered. It is recommended that CBGs are routinely checked for wear to the bolt and barrel if they are repeatedly fired in a session.