ll Gj. STUNNING OF CATTLE WITH PENETRATING CAPTIVE BOLT STUNNERS No. C/86 P.M. HUSBAND & F.D. SHAW -.J' ~,!!' 'U' Clfulo <ffiju.

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1 No. C/86 j1 ~,!!' J. -!!' 1- CRCULATON LST DATE OFFCER NTALS RECEVED STUNNNG OF CATTLE WTH PENETRATNG CAPTVE BOLT STUNNERS BY P.M. HUSBAND & F.D. SHAW RETURN TO OFFCE WHEN CRCULATON COMPLETE ll Gj.. GfudJ~~ Q;}13 aj'@ 'U' Clfulo <ffiju.v -.J'

2 This document is prepared primarily as a record of work which is either incomplete or is not to be formally published. ts distribution is strictly limited and it must not be used in bibliographies. r '\.)

3 SUMMARY The effectiveness of penetrating captive bolt stunners when used for the stunning of adult cattle was assessed at three abattoirs. Although the animals in the trials were of excitable temperament, 97% of animals were effectively stunned with a single application of the stunner. AUGUST, 1986.

4 (l. '~1 CONTENTS (~,/ SUMMARY NTRODUCTON METHODS EXPERMENTAL DETAL PAGE NO. RESULTS 2 DSCUSSON 3 ACKNOWLEDGEMENT 4 e APPENDX 5 REFERENCE 4 FGURE 6 FGURE 2 7,,, FGURE 3 8

5 NTRODUCTON The majority of Australian abattoirs use a penetrating captive bolt stunner for the stunning of cattle. nformation from a recent survey (Anon 1985) suggested that, in general, these stunners provided a humane and effective method of stunning. The survey results showed that in most abattoirs the vast majority of animals received only a single application of the stunner, however, in some abattoirs approximately 10% of cattle received one or more additional stuns. n an endeavour to obtain detailed information on the incidence and causes of multiple stunnings, a comprehensive investigation was conducted at three abattoirs. Two of the abattoirs were located in northern Western Australia, one in the Northern Terri tory. Stunning position, carcass weight, dentition and classification were recorded for 291 individual animals in the investigation. METHODS Two people were involved at each abattoir, their detailed tasks and method of recording are listed in Appendix A. One person was stationed at the knocking box to record the stunning position (front or back) and the number of times the animal was stunned. The second person, located on the slaughter floor, examined the heads and recorded the location of the penetration of the bolt (Fig. 1) and the animal's dentition. Carcass weights and classifications were subsequently obtained from abattoir records. EXPERMENTAL DETALS Abattoir 1 Observations were made on 112 animals, all Shorthorn or Brahman cross and all classified as steer or cow. Mean carcass weight was 202 kg, with a range of kg. The dentition varied. from temporary teeth (one animal) to broken mouth (one animal). All animals were stunned with a Schermer penetrating captive bolt stunner using black cartridges. This works was different from the others surveyed in that only 77% of animals were stunned from the front, while in the other works, in excess of 95% of animals were stunned from the front. Abattoir 2 Observations were made on two separate groups of animals, a group of 64 cows and a group of 28 bulls, the Schermer penetrating captive bolt stunner being used in both instances. Red cartridges were used with cows while black cartridges were used with the bulls. The mean carcass weight of the cows was 151 kg, with a range of kg, while for the bulls the mean carcass weight was 283 kg, with a range of kg. The cows were all Shorthorn or Poll Shorthorn while the bulls were Brahman, Brahman cross or Shorthorn. For the cows, the dentition varied between 6 tooth (one animal) and broken mouth (7 animals). The bulls' dentition range was also between 6 tooth (one animal) and broken mouth (3 animals)~ ~"J~

6 2 Abattoir 3 Observations were made on a total of 87 steers (Shorthorn or Brahman cross), all animals being stunned with a Schermer penetrating captive bolt pistol using black cartridges. The mean carcass weight was 261 kg, with a range kg. Dentition varied from 4 tooth (one animal) to broken mouth (one animal). Animal Temperament Practical limitations prevented any attempt at a formal assessment of the temperament of individual animals. However a subjective assessment of animal temperament was made and considered in conjunction with previous experience of animals at the abattoirs in question. This led to the conclusion that the animals under study were representative of those in the Northern Terri tory and Kimberley regions. Animals in these regions are reared on extensive properties where exposure to human contact is at best limited. The environment tends to be harsh and growth rates are such that the majority of animals are greater than four years of age at turn off. Given these circumstances, the animals tend to be easily frightened, and the process of mustering, drafting and transport over long distances generally results in animals arriving at the abattoir in a stressed condition. Thus, it can be said that, in general terms, the animals were excited rather than calm. RESULTS A summary of the results is listed in Table 1. TABLE 1: SUMMARY OF RESULTS OF TRALS NVOLVNG CATTLE STUNNED WTH PENETRATNG CAPTVE BOLT STUNNERS Number % Front Stunned Mean Carcass Weight % Single Stun ABATTOR 1. Steer/cow ABATTOR 2. Cow Bull ABATTOR 3. Steer One of the aims of the study was to ascertain reasons for the ineffective stunning of individual animals. Details for the 9 animals that received more than one stun are given below.

7 3 Abattoir 1. Three steers and one cow were stunned twice. Bolt penetration positions of 5 and 1 were recorded for one animal, for the remaining three animals, bolt penetrations were in positions other than position 5. These three animals were representative of the entire group, and it is possible that inaccurate positioning of the captive bolt stunner was a contributing factor to the initial inadequate stun. Abattoir 2. Two animals were stunned twice. n both cases the initial stun was at the back of the head, followed by a stun to the front of the head. Only 4 animals from the group of 94 were stunned behind the head. n two of these cases it was noted that the animals were very excited and presumably these animals were stunned from behind because of difficulties in gaining access to the front of the head. Thus, the main cause for failure to effectively stun at least one of these animals could have been excessive animal movement. Abattoir 3. Two steers were stunned twice while one steer was stunned three times. One of these animals received two stuns in position 5 and thus it would appear that poor positioning of the captive bolt was not a contributing factor to the ineffective stunning of the animal. This steer was representative of the group and there was no apparent reason for the ineffective stun. The steer that was stunned three times was the heaviest animal in the group (carcass weight 348 kg). The stun penetrations were in positions 9, 2 and 1, so it cannot be stated definitely that the size of the animal contributed to the ineffective stunning. t is possible that a single shot in position 5 may have been effective. DSCUSSON The results show that at least 97% of animals were effectively stunned with a single shot from the captive bolt stunner. n an abattoir an animal will receive a second stun if (i) it does not collapse following the first stun, or (ii) if it attempts to rise following the first stun, or (iii) if at any stage pr,ior to sticking the animal is making voluntary movements. There were no occasions during these trials when the observers believed a second stun was obviously necessary but not administered. t is reasonable to assume that the majority of animals that receive a single penetrating captive bolt stun have been humanely stunned. t is usually recommended that the captive bolt be applied at the intersection of imaginary diagonal lines between the eyes and ears, this point will be within position 5 (Fig.1 ). From the histograms (Figs. 2 and 3), it can be seen that 55%-85% of frontal stuns were applied to the correct position. n this study, it was not possible to prove that incorrect positioning of the stunner led to ineffective stunning, as

8 4 effective stunning seemed to be achieved with stunning positions well displaced from the midline. A total of 30 animals were effectively stunned with a bolt penetration in one of the lateral positions (1,4,7,3,6,9). n these cases, the bolt penetration would have been several centimetres from the midline. t should not however be deduced that stunning position is irrelevant; an examination of the anatomical relationships between the brain and the skull indicates the theoretical advantages of position 5. t.would appear that the stunner used in the$e trials is sufficiently powerful to ensure effective stunning with less than optimal location of the bolt. Experimental studies conducted in 1981 indicated that the Schermer pistol, whether powered by either red or black cartridges, generated a greater force than the captive bolt pistols produced by other manufacturers at that time (Lambooy 1981 ). An.examination of the details of the animals stunned more than once suggests, but does not prove, that in some cases incorrect positioning of the stunner contributed to the ineffective stunning..t\ With the vast majority of animals in these trials, an effective stun was achieved with the first application of the stunner. Ensuring this degree of effectiveness required skill and concentration on the part of the operator. Despite the apparent difficulties, it is clear that, even with animals of excitable temperament, a very high percentage can be effectively stunned by a single application of a penetrating captive bolt stunner. With less excitable animals, it should be possible to consistently achieve a first stun success rate closely approaching 100%. However, to achieve this figure, it will be necessary for the correct stunning equipment to be ~sed, for it to be regularly maintained, and for the stunner operator to be properly trained and supervised~ ACKNOWLEDGEMENT We wish to acknowledge the assistance provided by the management and staff at the three abattoirs. REFERENCES Anon. (1985). Survey of abattoir animal welfare. Dept. of Primary ndustry. Lambooy, E. (1981). Mechanical aspects of skull penetration by captive bolt pistol in bulls, veal calves and pigs. Fleischwirtsch.61 :

9 5 APPENDX ([~ nformation obtained by Person A, located at the knocking box and Person B, located on the slaughter floor after heads have been skinned. Person A MRL No. - Animals numbered serially from 1 to 100 Works No. - Number used by works to identify carcass Stunner/cartridge - Record make of stunner and colour of cartirdge Front/back -Stunning position Breed Person B MRL No. - Serial No. Works No. No. of Teeth- Temporary, 2,4,6,8, Broken mouth Number of stuns - Number of visible penetrations Position(s) - Location of penetration recorded as 1-9 as indicated in Figure 1.

10 Figure 1. Position chart for recording location of penetration of skull by captive bolt. (Position 5 is the theoretically correct position).

11 7 ABATTOR 1 (if le % 1fftt 9S as 7fil 68 sa 4fil 3fil 2B 1S " ~ ~ ~ ~ ~ i- i J 1 2 ' STUNNNG POSTON Ci ABATTOR 2 <BULLS> % lfftt 9fil as 7fil era Slil 4S 3fil 2S 1B ", ~ ' STUNNNG POSTON Figure 2. Histograms showing percentage of cattle stunned at each stunning position.(see Figure 1). (t~!t cj

12 8 % lflt r- era ~ era 1-7ra 1- era.. sra... 4ra... 3S!- 2ra 1- ls!- ra 1 r l,. ABATOR 2 <COWS> { :\1 ',, STUNNNG POSTON ABATOR 3 lftllrgra... as ~ 1ra... BS "'" % sra... 4S!- 3ra... 2S 1- lra... ra l STUNNNG POSTON 9 Figure 3. Histograms showing percentage of cattle stunned at each stunning position (s ee Figure 1).