Captive Bolt Pistol Research Articles

Self-inflicted head trauma using a captive bolt pistol: report of three cases

Three cases of self-inflicted head trauma using a captive-bolt pistol are described. This is a rarely reported phenomenon and presents with an unique pattern of brain injury.

Neuropathological changes produced by non-penetrating percussive captive bolt stunning of cattle

A blunt, non-missile head injury inflicted by a non-penetrating captive bolt pistol in cattle at slaughter resulted in immediate loss of consciousness, a depressed fracture of the frontal bone and widespread subarachnoid haemorrhage, particularly beneath the impact site, in the temporal and frontal lobes, and around the brainstem. There was also invariably petechial haemorrhage in the basal ganglia and thalamus. The large concussive force applied to the cranium by the stunner was probably responsible for rendering the animal insensible and the vascular damage produced by this force and the sudden ventrocaudal acceleration of the brain after impact. These findings supported the use of this mode of stunning, followed by exsanguination, as an acceptable form of slaughter of cattle in abattoirs.

Brain damage caused by a captive bolt pistol

The neuropathological changes produced by a captive bolt pistol are described. The primary wound track in the brain was similar to that inflicted by a weapon such as a .22 calibre rifle. However neural and vascular damage at a distance from the primary wound canal was much less severe and widespread after penetration of the low velocity captive bolt projectile due to the formation of a smaller temporary wound cavity by radial forces imparted to the parenchyma. These findings suggest that the use of a captive bolt pistol for euthanasia should be immediately followed by further actions to ensure that an animal is rendered permanently unconscious.

Electrical stunning of red deer (Cervus elaphus)

Eighteen of 23 red deer (Cervus elaphus) at a deer slaughtering premises were successfully stunned with an apparatus modified from that normally used to stun sheep. The five unsuccessful electrical stuns were associated with poor head restraint and poor head contact by the electrodes. The median stunning current was 0.9 A, and in the majority of cases the duration of stunning was less than 1 second. The signs of the electrically induced epileptiform seizures in the deer were dissimilar to those seen in sheep, cattle and pigs, in that the initial tonic phase was less marked, and of shorter duration. A similar shorter and less obvious tonic phase was noted in four deer shot with a captive bolt pistol. Two animals which were electrically stunned, and bled within 10 seconds, showed no signs of recovery while bleeding. The electroencephalograms of four deer stunned with currents of 1.3 A for a duration of either 0.5 or 1.0 seconds were recorded under more controlled conditions. All four animals developed electroencephalograms typical of an epileptiform seizure. The animals exhibited behavioural reactions similar to the other 18 animals in the trial at the deer slaughtering premises and were rendered unconscious for between 54 and 122 seconds. The electroencephalogram activity amplitude was greater than that recorded immediately before stunning and took between 6 and 9 seconds to build up to maximum value. It is concluded that, providing the heads of deer are adequately restrained, head-only electrical stunning can be incorporated into a humane method of slaughter for deer.

Homicide with a Captive Bolt Pistol

A homicide with a captive bolt pistol (slaughterer's gun) is reported. The construction and the function of this "humane killer" as well as the typical patterns of injury are described.

Reactions of Cattle to Head-Restraint at Stunning: A Practical Dilemma

AbstractThe behavioural reactions and blood Cortisol levels of cattle stunned using a penetrating captive-bolt pistol whilst standing free in a stunning box were compared with those obtained from cattle similarly stunned but with their heads held in a hydraulically operated chin-lift type of head restrainer. Few (8 out of 55) animals voluntarily put their heads into the restrainer, most had to be ‘persuaded’ to use the head-restrainer; some (5 out of 24) could not be. The mean time between entry into the stunning pen and the stun for 23 free standing animals was 5.6s and for 19 animals which could be persuaded to use the head restrainer was 34.2s. The Cortisol levels in the blood taken at the stick, from 30 animals stunned while standing free was 67.6 nmoVlitre while that from 30 stunned while head-restrained was 143.1 nmolHitre. The behaviour and Cortisol results suggest that enforced usage of this type of head restrainer could be a cause of distress to the cattle involved.

Investigation into the principal determinants of effective captive bolt stunning of sheep

In order to identify the physical component of captive bolt stunning responsible for abolishing visual evoked responses, experimental forms of captive bolt stunning were carried out on anaesthetised sheep. Supporting the captive bolt pistol away from the skull to permit limited penetration of the brain was found to be as effective as conventional shooting methods at abolishing visual evoked responses (responses were lost in all animals). Whereas, manual insertion of the bolt through a trephined hole or shooting through a trephined hole was significantly less effective (respectively, one of eight and four of eight animals lost responses). It is concluded that the impact of the bolt with the cranium is the principal determinant of effective stunning, rather than the penetration of the bolt into the brain tissues.

Right Ventricular Contusion

To investigate the pathophysiology and treatment of right ventricular (RV) contusion we assessed biventricular function via volume expansion in eight open-chest, anesthetized, ventilated dogs. Measurements were obtained before and after RV contusion with a captive bolt pistol and during dobutamine infusion. RV contusion depressed both RV and left ventricular (LV) performance as assessed by classical ventricular function curves (p less than 0.05). Dobutamine reduced filling pressure (p less than 0.05) and increased cardiac output (CO) (p less than 0.01) when infused post contusion. Because, on inspection, the LV was not contused, the apparent depression in LV function is most likely due to reduced diastolic compliance secondary to ventricular interdependence. In support of this possibility, in four dogs, LV performance significantly improved (p less than 0.05) when the pericardium was opened. We conclude that RV contusion can depress the relationship between CO and filling pressures in both ventricles and that dobutamine is superior to volume in treating the resultant low cardiac output state.

Immediate diagnosis of acute myocardial contusion by two-dimensional echocardiography: Studies in a canine model of blunt chest trauma

The purpose of this study was to assess the usefulness of two-dimensional echocardiography in the diagnosis of myocardial contusion resulting from blunt chest trauma. In 25 anesthetized dogs, blunt chest trauma was delivered to the right or left chest using a captive bolt pistol. Eighteen dogs survived. Two-dimensional echocardio-graphic recordings and myocardial perfusion determinations (microspheres) were performed before and 15 and 90 minutes after trauma. Pathologic examination confirmed and localized the extent of myocardial contusion. When trauma was delivered to the left side of the chest, two-dimensional echocardiographic and pathologic abnormalities were primarily in the anterolateral wall of the left ventricle; right chest trauma produced septal and right ventricular wall contusion. From short-axis two-dimensional echocardiographic recordings, the end-diastolic wall thickness and systolic function of regions that corresponded to areas of damage in anatomic sections were analyzed and compared with those of remote normal-appearing regions. The contused region showed increased end-diastolic wall thickness and impaired regional systolic function. Further, there was a visible increase in the echo brightness in the contused region. Regional perfusion was norma) and thus the functional impairment of the contused myocardium was not due to ischemia. Other abnormalities observed on the two-dimensional echocardiograms included pericardial effusion and discrete intramyocardial sonolucent zones due to hematomas. Contused myocardium can be identified on a two-dimensional echocardiogram by 1) increased end-diastolic wall thickness, 2) increased echo brightness, and 3) impaired regional systolic function. Two-dimensional echocardiography can also demonstrate other complications of cardiac trauma such as intramyocardial hematoma and hemopericardium.

Slaughter of deer

Deer farming in the British Isles is in its infancy but the industry is growing. Deer farmers retail their own venison from the farm having shot individual deer at close range as they graze. Although the method of killing is effective, humane and does not alarm the other deer, it is primitive. It is essential that as the industry expands, the normal retail channels used by the producers of other livestock be opened to deer farmers by means of appropriate legislation. Research into the special needs in slaughterhouses for deer is being undertaken, particularly in the lairage and devising a safe humane means of delivery to the point of slaughter. At the slaughter unit on Glensaugh experimental deer farm, a captive bolt pistol is used in a specially designed stunning pen. The carcases are prepared for sale in skin to the game trade, but environmental conditions are unsuitable for preparation of red meat for sale. However in-skin carcases have been transferred later to the red meat trade and prepared as boned out convenience packs.

Some aspects of the effectiveness of stunning in sheep by the captive bolt

The effects of penetration depth and the velocity of the bolt on the onset of unconsciousness was investigated in twenty-four sheep of about 45 kg liveweight. The sheeps' state of consciousness was judged from the electrocorticograms recorded via electrodes surgically pre-implanted frontally on the right side of the head. Sixteen sheep were trephined. A commercial captive bolt pistol and an experimental manual bolt, both with variable penetration depths, were used to represent high and low velocity stunning. Stunning by destroying only the cortex or by only penetrating the skull when the experimental bolt or captive bolt pistol, respectively, were used, did not produce unconsciousness. Unconsciousness was obtained after destroying the cortex and deeper parts of the brain with the experimental bolt (low velocity) or after destroying the cortex (and deeper parts of the brain by shockwaves) when using a captive bolt pistol (high velocity). To produce unconsciousness the captive bolt should have sufficient energy and length after penetration of the skull to crush the cortex and deeper parts of the brain, either directly or by shockwaves.

A comparison of the effects of electrical, captive bolt or percussion stunning on the incidence of blood splash in lambs

Three-hundred-and-three lambs were divided into three equal groups. Half the lambs in each group were not weaned before slaughter and the weaned half were slaughtered a week later. Lambs in one group were head stunned electrically before slaughter; in the second group lambs were stunned with a captive bolt pistol and in the third group they were percussion stunned before slaughter. Carcasses, gall-bladders, hearts and duodenums were inspected for blood splash after slaughter. A few small haemorrhages were detected in 57% of the electrically stunned lambs, in 30% of the captive bolt stunned lambs and in only 16% of the percussion stunned animals. Although no splash of commercial significance was found in any carcass, 25% of the electrically stunned lambs had detectably splashed carcasses, whilst only 1% of percussion-stunned lambs had splashed carcasses with captive bolt stunned lambs being intermediate in carcass splash incidence. These results show that stunning method affects the incidence of blood splash.

Experimental Cardiac Trauma—Ballistics of a Captive Bolt Pistol

Cardiac trauma can be experimentally produced by blunt impulsive impact over the cardiac apex in the anesthetized canine. A gradation of myocardial injury, including transient arrhythmia, contusion, and lethal ventricular fibrillation, can be produced by varying the power of the charge in a modified captive bolt pistol. Ballistics experiments were conducted to quantify the velocity, energy, and trajectory of impacts produced by the modified captive bolt pistol using various charges. Correlation of the impact data with the previously reported levels of trauma indicates that a 24 m/s impact with 178 joules of available energy results in lethal ventricular fibrillation with extensive myocardial contusion. Blunt impact at 17 m/s with 102 joules causes serious myocardial injury and at 13 m/s with 67 joules causes minor transient arrhythmia.

Contamination of the Deep Tissues of Carcasses by Bacteria Present on the Slaughter Instruments or in the Gut

Possible routes by which bacteria might reach the deep tissues of carcasses were tested by placing genetically ‘marked’strains of Escherichia coli, Clostridium perfringens or Bacillus thuringiensis on slaughter instruments before use and examining deep tissue samples for their presence post mortem. Bacteria present on the captive bolt pistol were recovered from the spleens of beef cattle and those placed on the pithing rod were found in both spleen and muscle of the flank and neck. Bacteria from the throat cutting (‘stick’) knife were isolated, on different occasions, from the heart, lung, spleen, liver and kidneys of sheep though rarely from their muscles. Orally administered bacteria were found in the spleen and lung, but not the musculature, of pigs.

The influence of slaughter method on the residual blood content of meat

AbstractThe effect of slaughter method on the residual haemoglobin content of the M. longissimus dorsi and the amount of blood lost at exsanguination of sheep was investigated. The influence of stunning method (electrical, 90 V, or captive bolt pistol), pithing and bleeding‐out position were examined. Sheep bled lying lost more blood than those bled hanging and electrically‐stunned animals lost more blood than those stunned with a captive bolt pistol; pithing had no effect. The residual haemoglobin content of the muscle did not vary significantly between methods and there was no relationship between it and the amount of blood lost at slaughter.

Relationships between time of stunning and time of throat cutting and their effect on blood pressure and blood splash in lambs

A study based on 84 electrically stunned lambs showed that those gash stuck (transverse incision of the extended neck which almost simultaneously severs the trachea, oesophagus, common carotid arteries and jugular veins and the spinal cord at the occipito-atlantal junction; Blackmore & Newhook, 1976) immediately after removal of the electrical applicator had a lower incidence of blood splash than lambs gash stuck 5–8 sec r stunning. Lambs whose throats were cut immediately before the application of the electrical current had the lowest incidence of blood splash. None of the splash observed was of commercial significance. Systolic blood pressure recordings were made on a further 12 lambs of a similar age, 10 of which were electrically stunned and two shot with a captive bolt pistol. Blood pressure changes observed were related to the blood splash results obtained in the first trial. Electrical stunning raised blood pressures to an average of 3·5 times normal in lambs allowed to recover from stunning. A further seven young unweaned lambs which were electrically or percussion stunned showed a similar pattern of blood pressure change to that reported for older lambs following stunning, except that lower maximum pressures were reached. The authors interpret the results of the present trials as indicating that the application of electrical current to the heads of lambs results in damage to small vessels prior to the elevation of blood pressure. This damage may become apparent in the dressed carcass and organs as small haemorrhages. The subsequent rise in blood pressure following stunning then exacerbates the leakage of blood into tissues and it becomes more apparent in the form of discrete haemorrhages or blood splash.

Changes in the arterial blood pressure of sheep stunned with a captive-bolt pistol.

Australian Veterinary JournalVolume 44, Issue 12 p. 574-576 CHANGES IN THE ARTERIAL BLOOD PRESSURE OF SHEEP STUNNED WITH A CAPTIVE-BOLT PISTOL W. R. Shorthose B.Sc., Ph.D., W. R. Shorthose B.Sc., Ph.D. CSIRO, Division of Food Preservation, Meat Research Laboratory, P.O. Box 12, Cannon Hill, Queensland, 4170Search for more papers by this author W. R. Shorthose B.Sc., Ph.D., W. R. Shorthose B.Sc., Ph.D. CSIRO, Division of Food Preservation, Meat Research Laboratory, P.O. Box 12, Cannon Hill, Queensland, 4170Search for more papers by this author First published: December 1968 https://doi.org/10.1111/j.1751-0813.1968.tb04935.xCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume44, Issue12December 1968Pages 574-576 RelatedInformation

Resistance of Cattle to the Tick Boophilus microplus (Canestrini). II. Stages of the Life Cycle of the Parasite against Which Resistance Is Manifest

Cattle infested daily with a constant number of larvae of the tick Boophilus microplus yield a relatively constant number of engorged adult females. The age structures of populations of ticks on animals of different resistance levels and which have achieved such a population balance have been analyzed to determine the stages of development against which resistance is manifest. All animals rejected larvae within 24 hr of infestation and the effect was greater on resistant animals. Resistant animals also rejected nymphs and adults at the time of attachment but those instars were not affected on animals of low resistance. Once a particular instar was established it was able to complete development within that instar except on one highly resistant animal which rejected nymphs progressively. On two animals there was an accumulation of young adult females of a size equivalent to 14 days' development. Individual animals have different degrees of resistance to the cattle tick, Boophilus microplus (Wilkinson, 1955). Further, Roberts (1968a) has shown that when animals are infested daily with a moderate number of larvae, a relatively constant number of female ticks mature each day, and that depending on the resistance levels of individual animals, between 50% and 100% of the applied larvae fail to reach maturity. Wilkinson (1955), Iitchcock (1955), and Riek (1962) have all suggested stages of the life cycle at which losses may occur, but there is no direct quantitative evidence as to the stage or stages against which host resistance is manifest. Degrees of resistance are relative and indicative of the ability of each animal to reject ticks, and are not necessarily relevant to the effect of the parasite on the host. As a population balance is established when animals are infested daily, then an analysis of the ages of all ticks on an animal in that state will be a reflection of the life cycle of the parasite on that particular host. In the present study a correlation between the ages and lengths of stages of B. microplus (Roberts, 1968b), was used to analyze the life cycle of the parasite on animals of different resistance levels. MATERIALS AND METHODS Animals and ticks The animals were all Bos taurus, taken from previous experiments (Roberts, 1968a), so that Received for publication 26 December 1967. all animal and tick handling procedures are as described. The infesting dose of larvae was also approximately 1,000 per day except for animal No. 5 which was receiving approximately 3,000 larvae per day. The animals selected had had at least 6 months' continuous tick experience at the time of slaughter. Processing of skin Animals to be killed were starved overnight and not infested on the day of slaughter. They were stunned with a captive bolt pistol, suspended by the hind legs, and bled from the jugular vein. The skin was removed as rapidly as possible, divided into areas, and placed in 10% formalin in phosphate-buffered saline (pH 7.2). The hide of the first animal examined was placed over a mesh with 6-inch squares, and the skin was cut to the squares, labeled, and placed into plastic bags. One half of the skin pieces were frozen at -20 C, and the other half were fixed in formalin. As the frozen pieces were required they were also fixed in formalin. The hides of all subsequent animals were divided along lines marked before the animals were killed. These were a horizontal line (A) from the patella through the ulnar process to the angle of the jaw, and two vertical lines circumscribing the animal at the patella (B), and the ulnar process (C). The area posterior to B was termed the rump. The area between B and C, and dorsal to A, was termed the sides. The area between B and C, and ventral to A, was termed the belly. The area anterior to C, and dorsal to A, was termed the neck and included the head. The area anterior to C, and ventral to A, was termed the brisket. Each area was divided into left and right sides before fixation. The fat was removed from each area of skin, which was then processed for 20 min in 10% sodium hydroxide at 80 C, which dissolved the hair and detached the ticks. The fluid was then passed through graded sieves ranging from No. 5 BSS (opening 3.35 mm) to No. 60 BSS (opening