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1.
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
2.
Concussive methods of pre-slaughter stunning in sheep: effects of captive bolt stunning in the poll position on brain function 总被引：1，自引：0，他引：1
The effectiveness of captive bolt stunning in the poll position was evaluated in eight anaesthetised sheep. Brain function following shooting was assessed using cortical visual evoked responses (VERs). Immediately following shooting, VERs were abolished in all sheep. However, in five of the sheep, VERs gradually recovered; responses became evident in these animals in a mean (+/- SE) time of 50 +/- 16.7 seconds. These results suggest that captive bolt shooting in the poll position can be associated with rapid recovery of brain function. Because such recovery could be associated with return of sensibility, shooting in the poll position should only be used when essential (ie, in horned animals) and then always followed promptly by sticking. 相似文献
3.
Averaged cortical evoked responses were used to evaluate brain function in anaesthetised sheep. Effects on both evoked somatosensory responses (SERs) and visual evoked responses (VERs) were examined. Following capitive bolt stunning, SERs and VERs were abolished instantaneously and did not reappear for the duration of the experiment. Similar results were found when animals were shot while conscious. It was concluded that captive bolt stunning in sheep produces an immediate, profound and long lasting brain failure and is therefore an effective preslaughter stunning method. 相似文献
4.
The effect of inducing a cardiac arrest or severing both carotid arteries on the spontaneous and visual evoked electrical activity in the brain were examined in anaesthetised turkeys. The time to loss of evoked activity was greater following the cardiac arrest. It was concluded that the potential humanitarian advantages of inducing a cardiac arrest at stunning are less pronounced in the turkey than for other poultry species. 相似文献
5.
Plasma concentrations of beta-endorphin were assayed in 10 sheep during the conscious state and in relation to electrical stunning. There was a 2 fold increase after stunning, and a further elevation following recovery. On this basis it is possible that recovery from electrical stunning at slaughter may cause undue distress, and it is suggested that exsanguination must be carried out promptly. 相似文献
6.
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
7.
The effects of head only or waterbath electrical stunning on somatosensory evoked responses in the brain of turkeys were examined. When head only stunning with a sinusoidal AC of 50 Hz was followed within 15 s by neck cutting the evoked responses were absent following the stun. When neck cutting was not performed, the evoked responses returned from 30 s after the stun. When currents between 120 and 250 mA were used in a waterbath stunner some birds retained their evoked responses immediately after the current was applied. The proportion of birds that retained their responses after the stun was not related to the level of the current that was applied. 相似文献
8.
The spontaneous EEG and somatosensory evoked potentials (SEPs) were examined in chickens before and after electrical stunning using a waterbath stunner. Fifty-four per cent of the birds became epileptic and lost their SEPs, and 17% were non-epileptic and appeared to retain their SEPs. It was concluded that there was a reasonably close association between the presence of epileptiform activity in the EEG and the absence of SEPs following electrical stunning, but that the absence of SEPs could be preferred as an indicator of an effective stun on conceptual grounds. 相似文献
9.
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
10.
The onset of insensibility during slaughter was studied in five, 31-day-old pigs. The state of sensibility was determined from the study of electroencephalograms (EEC) which were of a bipolar transhemispheric derivation. In 3 pigs slaughtered by bilateral severance of both common carotid arteries and jugular veins, it was judged that insensibility occurred within 25 s and there was no resurgence of cerebrocortical activity following subsequent respiratory gasps. The EEGs became isoelectric within 115 s. These results are compared with previous findings by the authors that adult sheep and lambs slaughtered by similar techniques became insensible within 7 s whereas, in calves, the onset of insensibility was delayed for up to 85 s and there were resurgences of cerebrocortical activity, following a respiratory gasp, for more than 300 s. These differences in the apparent onset of insensibility in the 3 species of animal are discussed in relation to the anatomical features and possible dynamics of the blood supply to the brain during slaughter. It is concluded that for humane reasons, head-to-back electrical stunning of pigs is preferable to a head-only method. 相似文献
11.
The principal blood vessels in the neck which are severed at slaughter in commercial poultry processing plants are described. Mechanical slaughtering methods often severed the spinal cord without cutting the carotid arteries. The manual method of slaughter cut one carotid artery plus one jugular vein. The effects of 9 different slaughtering methods on spontaneous and evoked electrical activity in the brain were examined in anaesthetised chickens and ducks. Severing the spinal cord without cutting the carotid arteries was found to result in death from asphyxia, and cutting one carotid artery plus one jugular vein was one of the slowest methods of killing the birds. Inducing a cardiac arrest at electrical stunning was the quickest method of inducing death. Spontaneous activity in the brain was lost before visual evoked activity. The times before loss of spontaneous activity varied between 23 and 233 s according to the method of slaughter and loss of evoked activity ranged between 90 and 349 s after slaughter. 相似文献
12.
The onset of insensibility during slaughter was studied in five, 31-day-old pigs. The state of sensibility was determined from the study of electroencephalograms (EEC) which were of a bipolar transhemispheric derivation. In 3 pigs slaughtered by bilateral severance of both common carotid arteries and jugular veins, it was judged that insensibility occurred within 25s and there was no resurgence of cerebrocortical activity following subsequent respiratory gasps. The EEGs became isoelectric within 115s. These results are compared with previous findings by the authors that adult sheep and lambs slaughtered by similar techniques became insensible within 7s whereas, in calves, the onset of insensibility was delayed for up to 85s and there were resurgences of cerebrocortical activity, following a respiratory gasp, for more than 300s. These differences in the apparent onset of insensibility in the 3 species of animal are discussed in relation to the anatomical features and possible dynamics of the blood supply to the brain during slaughter. It is concluded that for humane reasons, “head-to-back” electrical stunning of pigs is preferable to a “head-only” method. 相似文献
13.
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. 相似文献
14.
Somatosensory evoked responses (SEP) in a turkey's brain were determined after water-bath stunning with a 150-mA (constant current) delivered with 50, 300 or 600 Hz, or with 75 mA, delivered with 50-Hz alternating current (AC) in order to evaluate the effectiveness of stunning. Ninety-four BUT 9 turkey hens 12 weeks of age were surgically implanted with EEG recording and left wing nerve stimulating electrodes 4 hours before stunning. They were individually stunned by immersion of the head and upper part of the neck in a water bath for 4 s. Using a 150-mA current, all birds stunned at 50 Hz showed cardiac arrest and a flat EEG immediately after the stun with no SEP recovery. The incidence of cardiac arrest at stunning decreased with increasing current frequency but SEP were lost in all birds. In birds that survived the stun, the duration of SEP abolition was on average 69 and 34 seconds at 300 and 600 Hz, respectively. Stunning with a 75-mA AC, delivered with 50 Hz, induced cardiac arrest in 32 per cent of turkeys. SEP were abolished in only 71 per cent of the birds that survived the stun, with an average duration of SEP of 66 seconds. The results indicate that increasing the frequency of a 150-mA AC current leads to a decreased stunning efficiency. A current of 75 mA per bird is unacceptable since 29 per cent of the birds do not show SEP abolition. 相似文献
15.
Ten ducks were subjected to electrical stunning with their heads completely immersed in the water of a waterbath, and 10 ducks received the same current while only the bill and skin over the crop made contact with the water. The effect on visual evoked responses in the brain was examined. A higher proportion of birds had lost their visual evoked responses immediately following the current with whole head immersion. It is suggested that crop and bill immersion is less effective in disturbing brain function than whole head immersion. 相似文献
16.
G von Mickwitz A Heer T Demmler H Rehder M Seidler 《DTW. Deutsche tier?rztliche Wochenschrift》1989,96(3):127-133
Stamping-out of animals in case of infections diseases has to meet the requirements resulting from animal welfare, disease prevention, and practicability under conditions in practice. This is well qualified by application of electrical shock stunning with subsequent generation of ventricular fibrillation in cattle, swine and sheep. The scientific elements of the method, the procedure, and experiences in application of the method during the stamping-out of 340 cattle, 980 swine, 152 sheep and 18 goats are discussed in the paper. 相似文献
17.
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
18.
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
19.
Cortical function in cattle during slaughter: conventional captive bolt stunning followed by exsanguination compared with shechita slaughter 总被引：1，自引：0，他引：1
Brain function was examined in adult cattle after conventional captive bolt stunning or shechita slaughter, using eight animals in each treatment. The times to loss of evoked responses (visual and somatosensory) and spontaneous activity in the electro-corticogram were used to determine the onset of brain failure. Captive bolt stunning followed by sticking one minute later resulted in immediate and irreversible loss of evoked responses after the stun. Spontaneous cortical activity was lost before sticking in three animals, and in an average of 10 seconds after sticking in the remaining five animals. The duration of brain function after shechita was very variable, and particularly contrasted with captive bolt stunning with respect to the effects on evoked responses. These were lost between 20 and 126 seconds (means of 77 seconds for somatosensory and 55 seconds for visual evoked responses) and spontaneous activity was lost between 19 and 113 seconds (mean 75 seconds) after slaughter. 相似文献
20.
Physiologic reactions during the slaughter of cattle and sheep with and without stunning 总被引：1，自引：0，他引：1
In a first trial the cortical activity of cattle and sheep was tested using only an electrocorticogram (ECoG). The results showed a shorter phase after sticking or the ritual slaughter cut respectively, until the ECoG disappears in stunned animals. However, considering the time between stunning and the cervical state, the interval until disappearance of the ECoG was prolonged in the stunned animals. The observed time differences, however, are only a tendency and not statistically confirmed. Insofar, concerning animal protection, the different slaughter methods could be regarded equivalent. A second trial was designed in a manner to allow a more exact interpretation of the ECoGs and was completed by measuring visually and somatosensorically evoked potentials. Additionally, in contrast to the first trial, only adult cattle were used here. The results revealed shorter intervals until disappearance of cortical activities when using captive-bolt stunning. Also the variance was much lower in this trial than after ritual slaughter. The mean of the time differences was relatively low (5.5 seconds). It was especially remarkable that after captivebolt stunning absolutely no evoked potentials could be registrated, whereas these potentials lasted for 77 seconds (somatosensorically evoked potentials) and 55 seconds respectively (visually evoked potentials) after the ritual slaughter cut. Thus, after ritual slaughter a nervous conduction was measured up to 126 seconds in the extreme cases. However, from the results obtained it can not be concluded whether or not pain sensitivity occurred in the animals. 相似文献