Evaluation of a spring-powered captive bolt gun for killing kangaroo pouch young

Context: During commercial harvesting or non-commercial kangaroo culling programs, dependent young of shot females are required to be euthanased to prevent suffering and because they would be unlikely to survive. However, the current method for killing pouch young, namely a single, forceful blow to the base of the skull, is applied inconsistently by operators and perceived by the public to be inhumane. Aims: To determine whether an alternative method for killing pouch young, namely a spring-operated captive bolt gun, is effective at causing insensibility in kangaroo pouch young. Methods: Trials of spring-operated captive bolt guns were conducted first on the heads of 15 dead kangaroo young and then on 21 live pouch young during commercial harvesting. We assessed the effectiveness at causing insensibility in live animals and damage caused to specific brain areas. We also measured depth of bolt penetration and skull thickness. Performance characteristics (e.g. bolt velocity) of two types of spring-operated guns were also measured and compared with cartridge-powered devices. Key results: When tested on the heads of dead animals, the spring-operated captive bolt gun consistently produced a large entrance cavity and a well defined wound tract, which extended into the cerebrum, almost extending the full thickness of the brain, including the brainstem. When tested on live pouch young, the captive bolt gun caused immediate insensibility in only 13 of 21 animals. This 62% success rate is significantly below the 95% minimum acceptable threshold for captive bolt devices in domestic animal abattoirs. Failure to stun was related to bolt placement, but other factors such as bolt velocity, bolt diameter and skull properties such as thickness and hardness might have also contributed. Spring-operated captive bolt guns delivered 20 times less kinetic energy than did cartridge-powered devices. Conclusions: Spring-operated captive bolt guns cannot be recommended as an acceptable or humane method for stunning or killing kangaroo pouch young. Implications: Captive bolt guns have potential as a practical alternative to blunt head trauma for effective euthanasia and reducing animal (and observer) distress. However, operators must continue to use the existing prescribed killing methods until cartridge-powered captive bolt guns have been trialled as an alternative bolt propelling method. Additional keywords: animal welfare, blunt trauma, culling, euthanasia, humaneness, kangaroo harvesting

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 (160–175 psi, N = 82) and high (190 psi, 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 190 psi are inappropriate when shooting adult Zebu beef cattle with pneumatically powered penetrating captive bolt guns

Investigation Into the Humaneness of Slaughter Methods for Guinea Pigs (Cavia porcelus) in the Andean Region

Guinea pigs (Cavia porcelus) are an important source of nonhuman animal protein in the Andean region of South America. Specific guidelines regarding the welfare of guinea pigs before and during slaughter have yet to be developed. This study critically assessed the humaneness of 4 different stunning/slaughter methods for guinea pigs: cervical neck dislocation (n = 60), electrical head-only stunning (n = 83), carbon dioxide (CO(2)) stunning (n = 21), and penetrating captive bolt (n = 10). Following cervical neck dislocation, 97% of guinea pigs had at least 1 behavioral or cranial/spinal response. Six percent of guinea pigs were classified as mis-stunned after electrical stunning, and 1% were classified as mis-stunned after captive bolt. Increased respiratory effort was observed during CO(2) stunning. Apart from this finding, there were no other obvious behavioral responses that could be associated with suffering. Of the methods assessed, captive bolt was deemed the most humane, effective, and practical method of stunning guinea pigs. Cervical neck dislocation should not be recommended as a slaughter method for guinea pigs

Captive nut fastener securely joins brittle materials

Extension tube captive nut with a standard bolt joins assemblies with an inaccessible nut location. This fastener is excellent for joining brittle materials

Reusable captive blind fastener

A one piece reusable fastener capable of joining materials together from one side (blind backside) comprises a screw driven pin ending in a wedge-shaped expander cone. The cone cooperates within a slotted collar end which has a number of tangs on a cylindrical body. The fastener is set by inserting it through aligned holes in the workpieces to be joined. Turning the pin in one direction draws the cone into the collar, deforming the tangs radially outward to mate with tapered back-tapered hold in the workpiece, thus fastening the two pieces together. Reversing the direction of the pin withdraws the cone from the collar, and allows the tangs to resume their contracted configuration without withdrawing the fastener from the insertion hole. The fastener is capable of joining materials together from only one side with substantial strength in tension and shear over many resue attachment cycles, with no special operations on the main assembly parts other than the tapering of the back end of the insertion hole

The repulsive and feeding-deterrent effects of electropositive metals on juvenile sandbar sharks (Carcharhinus plumbeus)

Reducing shark bycatch and depredation (i.e., damage caused by sharks to gear, bait, and desired fish species) in pelagic longline fisheries targeting tunas and swordfish is a priority. Electropositive metals (i.e., a mixture of the lanthanide elements lanthanum, cerium, neodymium, and praseodymium) have been shown to deter spiny dogfish (Squalus acanthias, primarily a coastal species) from attacking bait, presumably because of interactions with the electroreceptive system of this shark. We undertook to determine the possible effectiveness of electropositive metals for reducing the interactions of pelagic sharks with longline gear, using sandbar sharks (Carcharhinus plumbeus, family Carcharhinidae) as a model species. The presence of electropositive metal deterred feeding in groups of juvenile sandbar sharks and altered the swimming patterns of individuals in the absence of food motivation (these individuals generally avoided approaching electropositive metal closer than ~100 cm). The former effect was relatively short-lived however; primarily (we assume) because competition with other individuals increased feeding motivation. In field trials with bottom longline gear, electropositive metal placed within ~10 cm of the hooks reduced the catch of sandbar sharks by approximately two thirds, compared to the catch on hooks in the proximity of plastic pieces of similar dimensions. Electropositive metals therefore appear to have the potential to reduce shark interactions in pelagic longline fisheries, although the optimal mass, shape, composition, and distance to baited hooks remain to be determined

Overview of current and alternative slaughter practices

The conventional cattle slaughtering process includes some critical stages where a dissemination of Specified Risk Material (SRM: brain, spinal cord) within or onto the carcass and within the slaughterhouse environment can occur. These processes are captive bolt stunning, removal of the head and first of all carcass splitting (sawing the spine lengthways). Captive bolt (CB) stunning results in massive brain tissue damage with bleeding, and in some cases brain tissue also emerges from the CB hole. As the heart is still functioning, there is a risk of brain tissue particles being transferred v i a the blood flow to heart and lungs or even in the whole carcass. This contamination risk is actually assessed to be low, but a continuing leakage of Central Nervous System (CNS) material from the captive bolt aperture in the further slaughter process may lead to direct and indirect contamination of carcass, meat and equipment. Therefore alternative stunning methods like electrical stunning or concussion stunning are discussed. A further critical point is the treatment of the head. When the head is removed, the spinal cord is cut with a knife. There is a danger of cross contamination due to spinal protein that may adhere to the knife and because of liquid cerebralis, which leaks from the foramen occipitale magnum. Further head cleaning with hand-held hoses following skinning also includes the danger of cross contamination from cleaning water or aerosol. Therefore measures regarding the safe handling of head and harvesting of head meat are proposed. The most critical point in terms of contamination of the meat surface with SRM is the currently common practise of sawing the spine vertically in the middle with hand-guided belt-type saws. A m i x t u r e of sawing residues and rinsing water (sawing sludge) collects in the housing of the saw, and if it contains infectious material this leads to contamination of the subsequent carcasses. The most promising methods available at present for minimising this risk appear to be in manual cattle slaughtering boning the entire (not split) carcass, either still warm or refrigerated and in industrial beef cattle slaughtering extraction of the spinal cord by vacuum from the whole carcass followed by conventional sawing or completely sawing out the spine including spinal ganglia