Prevalence of ballooning of the severed carotid arteries at slaughter in cattle, calves and sheep

Ng, Guseva; Shaw, F.D.; Whitford, Jackie; Patterson-Kane, Janet C.

doi:10.1016/j.meatsci.2006.05.021

Cited by 34 publications

(27 citation statements)

References 6 publications

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“…The arteries of an animal in which poor bleeding is observed, are in practice often re-cut to allow adequate bleeding. Poor bleeding may be caused by occlusion, which is characterized by retraction and contraction of the elastic portion of the arterial wall and thrombus formation around the severed end of the vessel (Gregory et al, 2006). The prevalence of carotid arterial occlusion in 576 cattle slaughtered at abattoirs in the United Kingdom was found to be 16% and 25%, respectively, for adult cattle and bobby calves (Gregory et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

“…Poor bleeding may be caused by occlusion, which is characterized by retraction and contraction of the elastic portion of the arterial wall and thrombus formation around the severed end of the vessel (Gregory et al, 2006). The prevalence of carotid arterial occlusion in 576 cattle slaughtered at abattoirs in the United Kingdom was found to be 16% and 25%, respectively, for adult cattle and bobby calves (Gregory et al, 2006). A study by Gregory et al (2010) showed that 71% of cattle taking longer than 75 s to collapse, had a false aneurysm in the cardiac end of the carotid that was at least 3 cm in diameter.…”

Section: Discussionmentioning

confidence: 99%

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Validation of indicators used to assess unconsciousness in veal calves at slaughter

Verhoeven

Gerritzen

Hellebrekers

et al. 2016

animal

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European legislation states that after stunning regular checks should be performed to guarantee animals are unconscious between the end of the stunning process and death. When animals are killed without prior stunning these checks should be performed before the animal is released from restraint. The validity of certain indicators used to assess unconsciousness under different stunning and slaughter conditions is under debate. The aim of this study was to validate the absence of threat-, withdrawal-, corneal-and eyelid reflex as indicators to assess unconsciousness in calves subjected to different stunning and slaughter methods. Calves (201 ± 22 kg) were randomly assigned to one of the following four treatments: (1) Captive bolt stunning followed by neck cut in an inverted position (n = 25); (2) Non-stunned slaughter in an upright position (n = 7); (3) Non-stunned slaughter in an inverted position (180°rotation) (n = 25); (4) Non-stunned slaughter in an upright position followed by captive bolt stunning 40 s after the neck cut (n = 25). Each calf was equipped with non-invasive electroencephalogram (EEG) electrodes before the slaughter procedure. All reflexes were verified once before the slaughter procedure. At the beginning of the procedure (T = 0 s) calves were stunned (treatment 1) or neck cut in an upright position (treatment 2, 4) or inverted position (treatment 3). Calves of treatment 4 were captive bolt stunned 34 ± 8 s after the neck cut. Reflexes were assessed every 20 s from T = 15 s for all treatments until all reflex tests resulted in a negative response three times in a row and a flat line EEG was observed. In addition, reflexes were assessed 5 s after captive bolt stunning in calves of treatments 1 and 4. Visual assessment of changes in the amplitude and frequency of EEG traces was used to determine loss of consciousness. Timing of loss of consciousness was related to timing of loss of reflexes. After captive bolt stunning, absence of threat-, withdrawal-, corneal-and eyelid reflex indicated unconsciousness as determined by EEG recordings. After non-stunned slaughter, both threat-and withdrawal reflex were on average lost before calves were unconscious based on EEG recordings. The eyelid-and corneal reflex were on average lost after calves had lost consciousness based on EEG recordings and appeared to be distinctly conservative indicators of unconsciousness in non-stunned slaughtered calves since they were observed until 76 ± 50 and 85 ± 45 s (mean ± SD), respectively, after EEG-based loss of consciousness.Keywords: electroencephalogram, calves, reflexes, slaughter, (un)consciousness ImplicationsMonitoring unconsciousness at slaughter is mandatory by European legislation and is often determined by the absence of behavioural indicators (i.e. loss of posture), physical signs (i.e. rhythmic breathing) and reflexes. Previous research in sheep has indicated that the absence of certain reflexes at slaughter is not a reliable indicator of unconsciousness. The present study showed that absence of the withdr...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Validation of indicators used to assess unconsciousness in veal calves at slaughter

Verhoeven

Gerritzen

Hellebrekers

et al. 2016

animal

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“…The reason is that at neck cutting only the external jugulars and the common carotids are severed, but not the vertebral arteries that continue to supply blood to the brain. In addition, after neck cutting, blood clots appear sometimes at the caudal ends of the severed carotids, causing occlusions and delaying the onset of unconsciousness (Bager et al, 1992;Anil et al, 1995a and1995b;Gregory et al, 2006). The chest-sticking technique is thus more efficient and particularly useful when reversible stunning techniques are used.…”

Section: Veal Calves and Adult Cattlementioning

confidence: 99%

Pre-slaughter conditions, animal stress and welfare: current status and possible future research

Terlouw

Arnould

Aupérin³

et al. 2008

Animal

169

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The present paper describes the main procedures used to slaughter fowl, pigs, calves and adult cattle, sheep, and farmed fish, starting on the farm and ending with the death of the animal at the abattoir. It reviews the currently known causes of stress, indicated by behavioural and physiological measurements on the animal level, and by post-mortem muscle metabolism. During the pre-slaughter period, psychological stress is due to changes of environment, social disturbances and handling, and physical stress is due to food deprivation, climatic conditions, fatigue, and sometimes pain. The exact causes of stress depend, however, on the characteristics of each species, including the rearing system. For fowl, bird catching and crating, duration and climatic conditions of transport and of lairage and shackling are the main known pre-slaughter stress factors. For pigs, stress is caused by fighting during mixing of pens, loading and unloading conditions, and introduction in the restrainer. Handling and novelty of the situation contribute to the stress reactions. For veal calves and adult cattle, disruption of the social group, handling, loading and sometimes unloading conditions, fatigue, novelty of the situation and for calves mixing with unfamiliar animals are known stress factors. Gathering and yarding of extensively reared lambs and sheep causes stress, particularly when shepherd dogs are used. Subsequent transport may induce fatigue, especially if sheep are commercialised through auctions or markets. In farmed fish, stress is predominantly related to environmental aspects such as temperature, oxygen, cleanliness of the water and, to a certain extent, stocking density and removal of the fish from the water. If transport and lairage conditions are good and their durations not too long, they may allow pigs, calves and adult cattle, sheep, and fish to rest. For certain species, it was shown that genetic origin and earlier experience influence reactions to the slaughter procedure. Stunning techniques used depend on the species. Pigs and fowl are mostly electrically or gas-stunned, while most adult cattle are stunned with a captive bolt pistol. Calves and sheep may be electrically stunned or with a captive bolt pistol. Various stunning methods exist for the different farmed fish species. Potential causes of stress associated with the different stunning procedures are discussed. The paper addresses further consequences for meat quality and possible itineraries for future research. For all species, and most urgently for fish, more knowledge is needed on stunning and killing techniques, including gas-stunning techniques, to protect welfare.

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“…The arteries of an animal in which poor bleeding is observed, are in practice often re-cut to allow adequate bleeding. Poor bleeding may be caused by occlusion, which is characterised by retraction and contraction of the elastic portion of the arterial wall and thrombus formation around the severed end of the vessel (Gregory et al, 2006). The prevalence of carotid arterial occlusion in 576 cattle slaughtered at abattoirs in the United Kingdom was found to be 16% and 25%, respectively, for adult cattle and bobby calves (Gregory et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

“…First, the 1 vertebral artery stays intact in bovine when the neck is cut and continues to supply blood to the brain (Daly et al, 1988). Secondly, occlusion of severed arteries may cause impaired bleeding in cattle and therefore prolonged consciousness (Gregory et al, 2006;Gregory et al, 2010).…”

Section: Slaughter Without Stunningmentioning

confidence: 99%

Assessing unconsciousness in livestock at slaughter

Verhoeven¹

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Verhoeven, M.T.W. (2016). Assessing unconsciousness in livestock at slaughter. PhD thesis, Wageningen University, The Netherlands Assessing unconsciousness in livestock at different stages of the slaughter process is a legal requirement according to EU legislation. The assessment can be based on absence of readily observable indicators (behavioural indicators, physical signs and reflexes) or, under experimental conditions, by recording and subsequent assessment of brain activity as presented in an electroencephalogram (EEG). There is no consensus, however, to what extent different behavioural indicators, physical signs and reflexes accurately reflect unconsciousness. The aim of this thesis was to study the relationships between these readily observable indicators and EEG activity to provide information on 1. the exact point in time at which animals lose consciousness when subjected to different stunning and slaughter methods and 2. the validity of behavioural indicators, physical signs and reflexes used to assess unconsciousness at slaughter under commercial conditions. The results showed a large variation in time to loss of consciousness, based on EEG activity, both between stunning and slaughter procedures and amongst animals. Captive bolt stunned calves lost consciousness instantly following the stun. Loss of consciousness in pigs during CO 2 stunning varied from 21 to 61 s after start of the exposure. An increased CO 2 concentration decreased the time to loss of consciousness. Times to loss of consciousness in sheep slaughtered without stunning varied from 6 to 24 s. In cattle slaughtered without stunning, times to loss of consciousness varied from 14 s up to over two minutes. Following captive bolt stunning in calves, absence of reflexes indicated unconsciousness. When consciousness was lost gradually (e.g. CO 2 stunning and nonstunned slaughter) none of the readily observable indicators could identify the exact point in time at which animals lost consciousness. Absence of rhythmic breathing, corneal reflex-and eyelid reflex were valid indicators of unconsciousness following CO 2 stunning and non-stunned slaughter, but these indicators were quite conservative as they were initially absent long after EEG activity indicated unconsciousness. When presence of these indicators would require (re)stunning, many animals will have to be (re)stunned. The results also showed that under full commercial conditions, stunning effectiveness must be closely monitored by slaughter plant employees, since risks for stun failures are higher under commercial conditions compared to experimental conditions. CONTENTS

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Prevalence of ballooning of the severed carotid arteries at slaughter in cattle, calves and sheep

Cited by 34 publications

References 6 publications

Validation of indicators used to assess unconsciousness in veal calves at slaughter

Validation of indicators used to assess unconsciousness in veal calves at slaughter

Pre-slaughter conditions, animal stress and welfare: current status and possible future research

Assessing unconsciousness in livestock at slaughter

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