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1.
The effects of head-to-back electrical stunning on the incidence of post-stunning reflex activity and cortical evoked responses were investigated in sheep. The stuns were effective in terms of inducing epileptiform activity and they resulted in cardiac fibrillation which ensured that there was no recovery of consciousness. Even though the corneal reflex and respiratory gasps were present, in 10 out of 12 sheep there were no concomitant visual and somatosensory evoked responses following a stun. In the remaining two, the responses were rudimentary and it would be unwise to conclude that the animals were conscious. It is suggested that brain stem reflexes following this stunning method should not be relied on as indices of recovery. The results support the view that an electrical stunning method which induces cardiac fibrillation results in improved animal welfare. 相似文献
2.
Chickens were electrically stunned either when their bodies and feathers were wet or when they were dry. The time to recovery of muscular activity following stunning with 81 mA was assessed, and it was found that it was quicker in the wet birds. When hens which had previously been implanted with electroencephalogram electrodes were stunned with 119 mA it was found that the prevalence of somatosensory evoked responses during the first 60 seconds after applying the current was not significantly influenced by the wetness of the birds. It was concluded that electrical stunning with low currents in wet birds leads to a lower prevalence of ventricular fibrillation at stunning and a shorter lasting stun in the non-fibrillated birds. This effect is possibly due to some of the current tracking over the bird's wet body rather than through the brain. 相似文献
3.
F Bager T J Braggins C E Devine A E Graafhuis D J Mellor A Tavener M P Upsdell 《Research in veterinary science》1992,52(2):162-173
Cerebral venous and femoral arterial blood samples were collected from 21 young calves either during electrical stunning and recovery or electrical stunning and slaughter by carotid severance or slaughter without stunning. The blood samples were analysed for PO2, PCO2, pH, glucose and lactate. The results were compared with simultaneous recordings of spontaneous electrocortical (ECOG) activity. Calves subjected to head-only electrical stunning and slaughter became permanently insensible at the time of the stun. The six calves slaughtered without stunning lost sensibility within 10 seconds. One calf, in which a clot formed in the carotid arteries inhibiting bleeding, maintained some evidence of cortical activity beyond 52 seconds; this was high amplitude low frequency activity and analysis by Fast Fourier Transform showed sensibility was not regained. In the remaining calves the ECOG activity was lost on average within 49 +/- 3.5 (SEM) seconds after slaughter. The cerebral extraction of metabolites increased after carotid severance, indicating inadequacy of cerebral bloodflow after slaughter. No correlations were found between indices of cerebral metabolism and the time of loss of cortical function. 相似文献
4.
This study examined the effectiveness of electrical stunning of turkeys applied at 150 mA per bird utilising a range of waveform-frequency combinations. In addition, the effect of stunning treatment on subsequent carcase quality was examined. The effectiveness of stunning, as judged by time to recovery, was similar regardless of bird weight or applied stunning treatment. Increasing waveform frequency was associated with a decrease in the prevalence of ventricular fibrillation, although turkeys appeared more susceptible than broilers. Use of the higher frequency waveforms (500 and 1500 Hz) was associated with a marked improvement in carcase quality, particularly with regard to breast muscle haemorrhaging and their use may result in considerable commercial advantage. 相似文献
5.
Extract Sir, — As from October 1976, all sheep in this country will have to be stunned prior to slaughter. Until recently it had been widely assumed that some form of electrical stunning would be the only practical method for use in New Zealand freezing works. Although for several years electrical stunning has been used for pigs in this country and other classes of stock overseas, only one meat export works in New Zealand has been stunning sheep electrically as a routine procedure for a complete season. 相似文献
6.
1. Hens were subjected to electrical stunning at 85, 105 or 125 mA per bird. The time to recovery of physical behaviour was measured in those birds which did not experience a cardiac arrest at stunning.
2. On average the duration of apparent insensibility lasted between 53 and 59 s, and at 105 mA per bird it was as short as 22 s in the bird which showed the quickest recovery.
3. Increasing the stunning current had no effect on the duration of insensibility. 相似文献
7.
Wenzlawowicz MV Holleben KV Bostelmann N 《DTW. Deutsche tier?rztliche Wochenschrift》2000,107(3):116-122
Stunning of poultry is still not solved satisfactorily. This concerns the requirements of animal welfare, meat quality and working conditions in the lairage, stunning and debleeding area. In an investigation of combined CO2-/O2-stunning in a new gas stunning system stress reactions of the animals during the induction phase and stunning effectivity were recorded in 7,000 chicken and 3.825 turkeys. During the induction phase (here: chicken 41 sek./turkeys 25-65 sec.) the animals first staid calm and then showed beak-opening as a consequence of the breathing stimulating effect of CO2. As a further sign of the aversiveness against CO2 the animals showed head shaking and wing flapping. The used settings of gas concentrations and stunning time in the system investigated lead to a very deep stunning resp. Killing of the animals. Therefore the debleeding cut could be performed late (chicken 44-55 sec., turkeys 54-90 sec.) after leaving the system without animals regaining consciousness. The stunning of turkeys with a mixture of CO2 and oxygen is an improvement according to animal welfare requirements because unnecessary pain and suffering, happening very often with electrical stunning, can be avoided. As far as animal welfare in chicken stunning is concerned it must be evaluated if gas stunning means an improvement because stress during the till now relatively long induction phase must be put into relation with comparably lower stress caused by hanging upside down and a fast and safe working electrical stunning unit. 相似文献
8.
For disease control in the case of epidemics killing of cattle via electrical stunning is a method of choice. The official veterinarian is responsible for monitoring the adhesion to animal welfare principles during electrical stunning and killing.This requires specialised knowledge and experience as the symptoms of effective stunning are quite variable in cattle. Signs of effective and ineffective stunning are described below. In addition to suitable technical equipment, restraint of the animals and correct use of the equipment, neurophysiological processes have to be considered. Calm handling of the animals avoiding stress is a prerequisite for ensuring animal welfare and minimising pain especially when killing cattle using electrical methods. 相似文献
9.
Blackmore DK Cook CJ Devine CE Gilbert KV Tavener A Langdon S Isaacs S Massland SA 《New Zealand veterinary journal》1993,41(3):126-130
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. 相似文献
10.
1. The effectiveness of electrical stunning of poultry was assessed where the recommended current of 105 mA per bird was applied using a range of waveform-frequency combinations. In addition the effect of the treatments on subsequent carcase quality was investigated. 2. The use of frequencies greater than 50 Hz was associated with a failure to induce ventricular fibrillation. 3. All waveform-frequency combinations were equally effective in producing a stunned state; the time to recovery was not affected by stunning treatment but was significantly longer in heavier birds. 4. The use of high frequency (500 Hz and 1500 Hz) stunning currents resulted in a decrease in carcase downgrading and a marked reduction in the occurrence of breast muscle haemorrhages, which represent significant commercial benefits to be gained by their use. 相似文献
11.
Pleiter H 《DTW. Deutsche tier?rztliche Wochenschrift》2004,111(3):106-108
Ever since the middle of the nineteen-eighties electrical stunning of cattle is used in industrial slaughter plants in New Zealand. Today electrical stun boxes operate in export slaughter plants throughout New Zealand. The reversible stun is utilised on the vast majority of slaughtered cattle. The electrical stunning (head only) immediately followed by bleeding is an alternative to ritual slaughter without prior stunning. Throughout the world's islamic community this alternative is widely accepted as Halal. 相似文献
12.
Broiler chickens were electrically stunned either by immersing their heads, necks and upper breast in a waterbath stunner or by immersing their heads only. The time to recovery of muscular activity was assessed, and it was found that the deeper immersion was associated with a slightly (10 second) shorter time to resumption of head righting. When hens which had previously been implanted with electroencephalogram electrodes were electrically stunned it was found that the incidence of somatosensory evoked responses during the first 60 seconds after applying the current was not influenced by the depth of immersion. It was concluded that depth of immersion had little influence on the effectiveness of electrical stunning. 相似文献
13.
Two pig abattoirs (A and B) equipped with an automated head-only and head-to-chest electrical stunning system, and two (C and D) equipped with a manual carbon dioxide stunning system, were evaluated to compare the effectiveness of stunning in a total of 10,454 pigs slaughtered under commercial conditions. In the abattoirs with the electrical stunning system, the percentage of animals that responded to a nose prick was significantly lower (P<0.05) in abattoir B, where a higher current intensity was used (P<0.05), than in abattoir A. No righting reflex was observed in the electrically stunned pigs. In the abattoirs with the carbon dioxide stunning system, the percentage of animals that responded to a nose prick and showed a righting reflex was significantly lower (P<0.05) in abattoir C, where the duration of the carbon dioxide cycle was longer and the interval between discharge from the system to sticking was shorter (P<0.05), than in D. Comparing the electrical and carbon dioxide stunning systems, the pigs stunned with carbon dioxide were significantly more responsive to a nose prick (P<0.05) and 25 per cent of them showed a righting reflex. Under the conditions of the study the fully automated head-only stunning with additional chest electrodes appeared to be more effective and less susceptible to incorrect handling than the manual carbon dioxide stunning system. 相似文献
14.
1. Fast Fourier transformations (FFTs) of electrocorticogram (ECoG) signals and averaging of somatosensory evoked potentials (SEPs) were used for assessing the impact of electrical stunning of ducks in a waterbath set to deliver a constant current of 150 mA, 600 Hz alternating current (AC) for 4 s. The effectiveness of stunning was determined on the basis of induction of epileptiform activity in the ECoG followed by a decrease in total power content to less than 10% of pre-stun values and abolition of SEPs. 2. One out of 10 birds was killed by the stun. FFT analysis of the ECoG signals of the remaining 9 birds showed that only one bird had a decrease of the total power to less than 10% of the pre-stun values for up to 70 s post-stun. The SEPs were retained in 6 out of 9 ducks and and 4 of them retained the evoked responses throughout the post-stun period. In the two birds showing abolition of SEPs, this was associated with a decrease in the total power content to below 10% of the pre-stun value. 3. The present experiment confirmed that the abolition of SEPs and the decrease of the total power below 10% of the pre-stun value for assessing unconsciousness after an electrical stunning in various species are also applicable to ducks. Based on this, it is concluded that electrical waterbath stunning of ducks using 150 mA of 600 Hz AC is ineffective. 相似文献
15.
The use of electrical stunning followed by electro-immobilization for the humane slaughter of cattle
Sir;- In New Zealand, calves are often electrically stunned before slaughter. However, electrical stunning is not usually used for adult cattle, primarily because the large size of the adult animal makes restraint more difficult, resulting in less reproducible stunning, with potential danger to personnel from animal movement. In addition, the slaughter of cattle may be inhumane if the stunning process does not ensure immediate and permanent insensibility (Newhook and Blackmore 1982b). The use and humaneness of electrical stunning of sheep and cattle have been the subject of our recent research, in which we have addressed and resolved many of these problems. We wish to relate our observations in the context of head-only electrical stunning of cattle followed by electro-immobilization to maintain insensibility and ensure carcass stillness. 相似文献
16.
Blackmore DK 《New Zealand veterinary journal》1989,37(2):59-61
Electrocardiograms (ECG's) were made from cattle and pigs after slaughter using only the left arm and right arm recording electrodes of a portable electrocardiogram with 12 recording electrodes. Functional heart activity was demonstrated in cattle after stunning with a captive bolt, nonpenetrative percussive methods and a head-only electrical technique. Recordings compatible with ventricular fibrillation were made in the majority of cattle and pigs subjected to a head-to-chest form of electrical stunning. In cases where the placement of stunning electrodes was defective, functional cardiac activity could be detected. Movement artefact on the ECG trace associated with epileptiform seizures following head-only electrical stunning was a technical problem. This was reduced by restunning the animal with a captive bolt before taking an ECG. The examination of ECG's made subsequent to slaughter could form an important component of the quality control of Halal slaughter or a slaughter process using the head-to-body electrical stunning techniques. Adoption of this would be facilitated by the development of a more simple and less sensitive electrocardiograph than that used in the present investigation. 相似文献
17.
Vogel KD Badtram G Claus JR Grandin T Turpin S Weyker RE Voogd E 《Journal of animal science》2011,89(5):1412-1418
Many small slaughter facilities use head-only electrical stunning to render swine unconscious and insensible to pain before slaughter. Head-only electrical stunning is a reversible procedure that is optimally effective for approximately 15 s after stun completion. In many small North American slaughter plants, the authors have observed hoist speeds that are too slow to achieve a short enough stun-to-bleed interval to maintain insensibility through exsanguination. Unlike many European plants, there is no separate high-speed hoist for pigs and exsanguination on the floor is not condoned. As a result, a 2-stage stunning method was proposed where head-only stunning for 3 s was immediately followed by application of the same stunning wand to the cardiac region of the animal for 3 s while lying in lateral recumbancy. A paired-comparison study was conducted on 89 pigs in a small slaughter facility to compare the head-only method applied for 6 s with the head/heart method. The objective was to evaluate signs of return to sensibility, stun-to-bleed time, blood lactate concentration, muscle pH, drip loss, and fresh meat color to validate the head/heart electrical stunning method for small slaughter plants. Incidence of corneal reflex was not different (P > 0.05) between head/heart (93.8%) and head only (85%) stunning. Nose twitching was more common (P < 0.05) in head only (26.5%) than head/heart (5%) stunning. Head/heart stunning eliminated rhythmic breathing, natural blinking, eye tracking to moving objects, and righting reflex, which were all observed in head-only stunned pigs. Eye tracking to moving objects was observed in 40.8% of head-only stunned pigs. Blood lactate was not different (P > 0.05) between stunning methods (head only: 8.8 ± 0.7 mmol/L, head/heart: 7.8 ± 0.7 mmol/L). Stun-to-bleed time did not differ (P > 0.05; head only: 32 ± 1 s, head/heart: 33 ± 1 s). Mean time to loss of heartbeat with the head-only method was 121 ± 5 s. No heartbeat was observed with the head/heart method. Longissimus thoracis pH, color, and drip loss were not different (P > 0.05) between stunning methods. This study determined that the head/heart electrical stunning method reduces the incidence of signs of return to sensibility without significant effects on meat quality, plant operation speed, or blood lactate concentration. In addition, the head/heart method requires no capital investment for plants that are currently using the head-only method. 相似文献
18.
The study hypothesis was that pre-slaughter handling is not conducted in such a way that pigs can be considered humanely slaughtered, nor is it conducive to promoting those properties of fresh meat that could enhance pork quality. The 1st phase of the investigation was aimed at confirming the present compliance level within the prescribed norms. To this end the importance of stunning induction requirements for effective electrical stunning, the welfare implications relating to the pre-slaughter handling of pigs and the stunning and sticking techniques were investigated. Pre-slaughter welfare of the pigs at the abattoir was found to be influenced at the outset by the origin and type of pig slaughtered, the daily throughput range of pigs and the type of abattoir involved. A disappointing pre-arrival aspect was that deficiencies in road motor vehicles were observed while off-loading pigs. Through poor design or lack of maintenance, another factor that hampered free movement of pigs was the off-loading facilities. The nature of animal behaviour in the pens, in the passages and when going into the stunning area was directly related to the pig handling efficiency and to the nature and extent of design and maintenance problems with equipment. None of the abattoirs had a well designed in-feed to a well planned stunning area/facility, and a very high level of pig pre-slaughter stress prevailed. The optimum position of the electrodes is virtually impossible to attain under practical conditions and the practice of repeat application of electrical stunning is common. Of the total sample size (n = 1175), 34% were difficult to shackle, 90% of these being from the abattoirs tending to slaughter more routinely a wide range of different sized pigs. In this survey 149 pigs (13%) required more than a single sticking attempt to bleed out properly, considerably higher than in other published reports. 相似文献
19.
1. According to the loading density there is a significant increase of the physical burden (strain) during a transport of pigs to the slaughterhouse. Keeping up minimal requirements (kgs pigs/sqm) the stress reaction decreases and the meat quality becomes better. 2. Each transport produces excitement which can be shown in higher respiratory and heart frequencies. The slaughtering of excited animals shows a higher percentage of carcasses with bad meat quality. Waiting times from at least 2 hours up to a maximum of 4 hours shows that the percentage of carcasses with a better meat quality increases. 3. Handling of animals at the slaughterhouse prior to stunning by dividing the number of pigs into small groups of at least 9 animals is very important especially because it reduces the excitement of the pigs prior to stunning. The stunning results are getting better. Mistakes in handling pigs prior to stunning especially in guiding them to the stunning place usually destroy all positive efforts for optimal transparent conditions and keeping up waiting times after transport. 4. The last step ahead to the stunning equipment. No good solution does exist which makes the pigs willingly do this last step and enter the place where the stunning is performed. This results in the CO2 stunning system itself as well as in the automatic electrical stunning equipment using a restrainer. 5. Stunning with CO2. 相似文献
20.
Solving return-to-sensibility problems after electrical stunning in commercial pork slaughter plants
Grandin T 《Journal of the American Veterinary Medical Association》2001,219(5):608-611
OBJECTIVE: To determine causes and solutions for return-to-sensibility problems after electrical stunning in pigs. DESIGN: Case studies. SAMPLE POPULATION: 6 federally inspected pork slaughter plants. PROCEDURE: 100 to 200 pigs were scored in each plant for stunner positioning, squealing when stunner was applied, and signs of insensibility. All pigs were held in a V-shaped restrainer conveyor and stunned with a manually applied head-to-body electrical stunner. RESULTS: Percentage of pigs that had blinking after stunning ranged from 0.5 to 7. None of the pigs had a righting reflex or kicked in response to stimuli. All signs of possible return to sensibility disappeared before bleeding pigs reached the scalding tub. Spontaneous eye blinking was eliminated by improving bleeding practices to increase blood flow, ergonomically redesigning the stunner operator's work station to make correct placement of the stunner easier, redesigning the head electrode to facilitate correct placement, reducing line speed from 1,200 to 1,080 head/h, correcting problems with poor initial contact of the stunner, and increasing amperage of a stunner that was set too low for sows. In 1 plant, a fatigued operator was the cause of stunner placement mistakes that resulted in signs of returning to sensibility. CONCLUSIONS AND CLINICAL RELEVANCE: Problems with electrical stunning can be easily corrected, but effective stunning requires monitoring of correct electrode placement, amperage, and bleeding procedures. Observation of spontaneous natural eye blinking without touching the eye is recommended for use under field conditions, because it is less prone to misinterpretation than are other methods. 相似文献