Use of a marker organism to model the spread of central nervous system tissue in cattle and the abattoir environment during commercial stunning and carcass dressing

Due to concerns about a link between variant Creutzfeldt-Jakob disease in humans and similar prion protein-induced disease in cattle, i.e., bovine spongiform encephalopathy (BSE), strict controls are in place to exclude BSE-positive animals and/or specified risk materials including bovine central nervous system (CNS) tissue from the human food chain. However, current slaughter practice, using captive bolt guns, may induce disruption of brain tissues and mobilize CNS tissues into the bovine circulatory system, leading to the dispersion of CNS tissues (including prion proteins) throughout the derived carcass. This project used a marker (antibiotic-resistant) strain of Pseudomonas fluorescens to model the effects of commercial captive bolt stunning procedures on the movement of mobilized CNS material within slaughtered animals and the abattoir environment. The marker organism, introduced by injection through the bolt entry aperture or directly using a cartridge-fired captive bolt, was detected in the slaughter environment immediately after stunning and in the abattoir environment at each subsequent stage of the slaughter-dressing process. The marker organism was also detected on the hands of operatives; on slaughter equipment; and in samples of blood, organs, and musculature of inoculated animals. There were no significant differences between the results obtained by the two inoculation methods (P < 0.05). This study demonstrates that material present in, or introduced into, the CNS of cattle during commercial captive bolt stunning may become widely dispersed across the many animate and inanimate elements of the slaughter-dressing environment and within derived carcasses including meat entering the human food chain.     

The use of a marked strain of Pseudomonas fluorescens to model the spread of brain tissue to the musculature of cattle after shooting with a captive bolt gun

AIMS: The aim of this study was to use a marked strain of Pseudomonas fluorescens to model the spread of central nervous system (CNS) tissue in cattle following captive bolt stunning. METHODS AND RESULTS: The marked organism was introduced by injection through the captive bolt aperture immediately after stunning and was subsequently detected in a wide range of derived tissues, including blood, organs, and the musculature of the entire forequarters of test animals. This was dependent on the use of high concentrations of the organism that were recovered sufficiently and rapidly to minimize the bactericidal properties of the circulatory system. These results suggest that a marked organism could potentially be used to model the effects of captive bolt stunning on the dissemination of CNS tissue from the brain. CONCLUSIONS: These results indicate that current commercial methods of captive bolt stunning may induce widespread and significant mobilization of CNS tissue within beef carcasses. This may lead to the widespread dissemination of such materials within meat destined for human consumption. SIGNIFICANCE AND IMPACT OF THE STUDY: In the absence of rapid, simple and sufficiently sensitive methods for the direct detection of prion in commercially slaughtered animals, marked organisms can provide useful models in studies of the dissemination kinetics of prion disease in captive bolt stunned animals.     

Penetrating Captive Bolt Stunning and Exsanguination of Cattle in Abattoirs

Abattoirs commonly use penetrating captive bolt pistols to stun cattle. Humane slaughter requires that an animal immediately becomes unconscious and does not regain consciousness. In this review we consider the concepts of concussion, unconsciousness, and return to consciousness. We conclude that an animal effectively stunned with a penetrating captive bolt pistol, as indicated by the presence of certain signs and the absence of others, has little possibility of brain function returning. Appropriate monitoring at all stages between stunning and sticking would ensure immediate detection and restunning on those few occasions when brain function was returning. When a captive bolt irreversibly stuns animals, sticking has no role in terms of animal welfare; its only function is to relieve the carcass of blood. With effective initial stunning and subsequent monitoring, specifying a stun-to-stick interval appears unnecessary. Abattoir surveys have indicated that it is possible to approximate, or even actually obtain, 100% successful stunning from a single shot. Furthermore, low prevalence of recovery follows. Thus, penetrating captive bolt stunning can form part of a process for the humane slaughter of cattle. This article outlines an approach to implementing standard operating procedures for checking the effectiveness of captive bolt stunning.     

Penetrating Captive Bolt Stunning and Exsanguination of Cattle in Abattoirs

Abattoirs commonly use penetrating captive bolt pistols to stun cattle. Humane slaughter requires that an animal immediately becomes unconscious and does not regain consciousness. In this review we consider the concepts of concussion, unconsciousness, and return to consciousness. We conclude that an animal effectively stunned with a penetrating captive bolt pistol, as indicated by the presence of certain signs and the absence of others, has little possibility of brain function returning. Appropriate monitoring at all stages between stunning and sticking would ensure immediate detection and restunning on those few occasions when brain function was returning. When a captive bolt irreversibly stuns animals, sticking has no role in terms of animal welfare; its only function is to relieve the carcass of blood. With effective initial stunning and subsequent monitoring, specifying a stun-to-stick interval appears unnecessary. Abattoir surveys have indicated that it is possible to approximate, or even actually obtain, 100% successful stunning from a single shot. Furthermore, low prevalence of recovery follows. Thus, penetrating captive bolt stunning can form part of a process for the humane slaughter of cattle. This article outlines an approach to implementing standard operating procedures for checking the effectiveness of captive bolt stunning.     

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

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.     

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

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.     

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 (CO₂) 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 CO₂ 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.     

Intraspecies transmission of BASE induces clinical dullness and amyotrophic changes

The disease phenotype of bovine spongiform encephalopathy (BSE) and the molecular/ biological properties of its prion strain, including the host range and the characteristics of BSE-related disorders, have been extensively studied since its discovery in 1986. In recent years, systematic testing of the brains of cattle coming to slaughter resulted in the identification of at least two atypical forms of BSE. These emerging disorders are characterized by novel conformers of the bovine pathological prion protein (PrP(TSE)), named high-type (BSE-H) and low-type (BSE-L). We recently reported two Italian atypical cases with a PrP(TSE) type identical to BSE-L, pathologically characterized by PrP amyloid plaques and known as bovine amyloidotic spongiform encephalopathy (BASE). Several lines of evidence suggest that BASE is highly virulent and easily transmissible to a wide host range. Experimental transmission to transgenic mice overexpressing bovine PrP (Tgbov XV) suggested that BASE is caused by a prion strain distinct from the BSE isolate. In the present study, we experimentally infected Friesian and Alpine brown cattle with Italian BSE and BASE isolates via the intracerebral route. BASE-infected cattle developed amyotrophic changes accompanied by mental dullness. The molecular and neuropathological profiles, including PrP deposition pattern, closely matched those observed in the original cases. This study provides clear evidence of BASE as a distinct prion isolate and discloses a novel disease phenotype in cattle.     

Establishment of an SV40 large T antigen-immortalized bovine brain cell line and its neuronal differentiation by dibutyryl-cyclic AMP

Immortalized bovine brain cell lines provide ideal in vitro cellular infection models for bovine spongiform encephalopathies (BSEs) caused by prions without enduring species barrier. We have established an immortalized brain cell line (FBBC-1 cells) from primary cultures of cryopreserved fetal bovine brain tissues after transfection with SV40 large T antigen. FBBC-1 cells are stable after passaging to >100 population doublings after single cell cloning, with a generation time of 24 h. After the treatment with dibutyryl-cyclic AMP, the cells ceased proliferation and extended neurite-like processes that were immunostained with the antibody against tubulin βIII, a marker of immature neurons. Upregulation of tubulin βIII expression was confirmed by immunoblotting. These bovine cells expressed cellular prion protein and its processed smaller C1 fragment, and may provide an in vitro means of propagating cattle BSE prion.     

Sources of Escherichia coli O157 and experiences over the past 15 years in Sheffield, UK

In the first documented outbreak of HC caused by Escherichia coli O157, which occurred in the North-west USA in 1982, there was a strong association between infection and prior consumption of ground beef from a chain of fast food restaurants. Foods of bovine origin, including beef, milk and dairy products, have since been implicated in many outbreaks of infection world-wide. Investigations during the course of outbreaks, or at random, have shown that cattle are a major reservoir of E. coli O157. E. coli O157 was isolated from cattle at slaughter in Sheffield in 1987, this being the first isolation from cattle in the UK. Following a cluster of cases in May/June 1992, an abattoir study showed the organism to be present in 4% of cattle at slaughter and on up to a third of carcasses from rectal swab-positive animals. E. coli O157 was isolated from a food source (unpasteurized milk), for the first time in the UK, in Sheffield in May 1993. During surveillance in 1995-6, E. coli O157 was isolated from 15.7% of cattle, with a monthly prevalence which varied from 5 to 37%. E. coli O157 was also isolated from 2.2% of sheep. During surveillance in 1996, E. coli O157 was isolated from 5.9% of samples of lamb products and from 1.5% of samples of beef products, despite the prevalence in cattle being much higher than in sheep. Work is in progress to try to explain this higher prevalence in lamb products. During 1997 in Sheffield, the only cases of E. coli O157 for which a confirmed source was established were associated with direct animal contact on farm visits. During on-farm investigations of these cases, E. coli O157 was isolated from faecal samples from adult cattle, calves, three different breeds of sheep, two different breeds of pigs, goats and a pony.     

Factors Affecting Penetrating Captive Bolt Gun Performance

Captive bolt stunning is used for rendering livestock insensible at slaughter. The mechanical factors relating to performance of 6 penetrating captive bolt gun (CBG) models were examined. The Matador Super Sécurit 3000 and the .25 Cash Euro Stunner had the highest kinetic energy values (443 J and 412 J, respectively) of the CBGs tested. Ninety percent (27/30) of CBGs held at a government gun repository (United Kingdom) were found to have performed at a normal standard for the model, while 53% (10/19) of commercial contractor CBGs tested were found to underperform for the gun model. When the .22 Cash Special was fired 500 times at 4 shots per min, the gun reached a peak temperature of 88.8°C after 2.05 hr. Repeat firing during extended periods significantly reduced the performance of the CBG. When deciding on the appropriate CBG/cartridge combination, the kinetic energy delivered to the head of the nonhuman animal, bolt penetration depth, and species/animal type must be considered. It is recommended that CBGs are routinely checked for wear to the bolt and barrel if they are repeatedly fired in a session.     

The effects of preslaughter washing on the reduction of Escherichia coli O157:H7 transfer from cattle hides to carcasses during slaughter

Fresh bovine faeces were inoculated with a non-toxigenic, antibiotic resistant strain of Escherichia coli O157:H7, spread on the rump areas of 30 heifers and allowed to dry for 24 h. Ten of the cattle then entered the normal slaughter process without further treatment. The remaining cattle were washed with a powerhose for 1 min (10 animals) and 3 min (10 animals) before entering the normal slaughter process. Both washing treatments removed all visible faecal materials on the live animals although a significant reduction (P < 0.05) in E. coli O157:H7 levels on the hides was only observed on those animals which were powerhosed for 3 min. After slaughter, E. coli O157:H7 was detected on carcasses and on the knives and hands of operatives. Preslaughter washing for 3 min did not statistically reduce the numbers of E. coli O157:H7 transferred from the hide to the carcass during slaughter. However, the organism was not detected on three of the four areas of the carcass sampled, indicating that washing may be a suitable method of decontamination animal hides before slaughter and as such deserves further investigation.     

Contamination of the Deep Tissues of Carcasses by Bacteria Present on the Slaughter Instruments or in the Gut

Possible routes by which bacteria might reach the deep tissues of carcasses were tested by placing genetically 'marked'strains of Escherichia coli, Clostridium perfringens or Bacillus thuringiensis on slaughter instruments before use and examining deep tissue samples for their presence post mortem . Bacteria present on the captive bolt pistol were recovered from the spleens of beef cattle and those placed on the pithing rod were found in both spleen and muscle of the flank and neck. Bacteria from the throat cutting ('stick') knife were isolated, on different occasions, from the heart, lung, spleen, liver and kidneys of sheep though rarely from their muscles. Orally administered bacteria were found in the spleen and lung, but not the musculature, of pigs.     

Indicators used in livestock to assess unconsciousness after stunning: a review

Assessing unconsciousness is important to safeguard animal welfare shortly after stunning at the slaughter plant. Indicators that can be visually evaluated are most often used when assessing unconsciousness, as they can be easily applied in slaughter plants. These indicators include reflexes originating from the brain stem (e.g. eye reflexes) or from the spinal cord (e.g. pedal reflex) and behavioural indicators such as loss of posture, vocalisations and rhythmic breathing. When physically stunning an animal, for example, captive bolt, most important indicators looked at are posture, righting reflex, rhythmic breathing and the corneal or palpebral reflex that should all be absent if the animal is unconscious. Spinal reflexes are difficult as a measure of unconsciousness with this type of stunning, as they may occur more vigorous. For stunning methods that do not physically destroy the brain, for example, electrical and gas stunning, most important indicators looked at are posture, righting reflex, natural blinking response, rhythmic breathing, vocalisations and focused eye movement that should all be absent if the animal is unconscious. Brain stem reflexes such as the cornea reflex are difficult as measures of unconsciousness in electrically stunned animals, as they may reflect residual brain stem activity and not necessarily consciousness. Under commercial conditions, none of the indicators mentioned above should be used as a single indicator to determine unconsciousness after stunning. Multiple indicators should be used to determine unconsciousness and sufficient time should be left for the animal to die following exsanguination before starting invasive dressing procedures such as scalding or skinning. The recording and subsequent assessment of brain activity, as presented in an electroencephalogram (EEG), is considered the most objective way to assess unconsciousness compared with reflexes and behavioural indicators, but is only applied in experimental set-ups. Studies performed in an experimental set-up have often looked at either the EEG or reflexes and behavioural indicators and there is a scarcity of studies that correlate these different readout parameters. It is recommended to study these correlations in more detail to investigate the validity of reflexes and behavioural indicators and to accurately determine the point in time at which the animal loses consciousness.     

Prion Infectivity in Fat of Deer with Chronic Wasting Disease

Chronic wasting disease (CWD) is a neurodegenerative prion disease of cervids. Some animal prion diseases, such as bovine spongiform encephalopathy, can infect humans; however, human susceptibility to CWD is unknown. In ruminants, prion infectivity is found in central nervous system and lymphoid tissues, with smaller amounts in intestine and muscle. In mice, prion infectivity was recently detected in fat. Since ruminant fat is consumed by humans and fed to animals, we determined infectivity titers in fat from two CWD-infected deer. Deer fat devoid of muscle contained low levels of CWD infectivity and might be a risk factor for prion infection of other species.Prion diseases are fatal neurodegenerative diseases that include Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy (BSE) in cattle, scrapie in sheep, and chronic wasting disease (CWD) in cervids. Cross-species prion infection can occur and is responsible for the spread of BSE to humans (2). Since spread is likely due to exposure to infected tissues, it is vital to know which tissues contain infectivity. In animals such as cattle, sheep, and cervids, whose tissues are part of both the human and domestic-animal food chains, the central nervous system (CNS) has the highest propensity for infectivity. Lymphoid organs and muscles can also be positive for the disease agent, but this varies among species (1, 4, 7). We recently found prion infectivity in brown and white fat of scrapie agent-infected mice (13) and wanted to determine if fat from animals actually consumed by humans may also carry infectivity. To answer this question, we inoculated fat from two CWD agent-infected deer into susceptible transgenic mice expressing deer prion protein (TgDeerPrP mouse) (10).     

The effects of stunning methods on product qualities in force-fed ducks and geese. 2. Fatty liver quality

This study investigated the effects of various stunning methods on the quality of French 'foie gras' in ducks and geese. The ducks (n = 30 per group) were stunned with one of the following techniques: electrical stunning in a water bath (50 Hz AC, 130 mA, 4 s), head-only electrical stunning (50 Hz AC, 600 mA, 4 s), mechanical stunning (captive bolt) and controlled atmosphere stunning (CAS: phase 1, CO2 (40%)-O2 (30%)-N2 (30%), for 2 min followed by phase 2, CO2 >85% in air, for 2 min). The same methods (except head-only stunning which was not applied) were used in geese (n = 40 per group). The weight of the liver at slaughter was not affected by the stunning techniques, neither was its colour (L*, a*, b* coordinates), despite the differences in bleeding rate between the stunning treatments. The loss of fat during the cooking of canned fatty liver did not depend upon stunning treatment. Some appearance defects of raw fatty livers were significantly affected by the treatment: mechanical and head-only stunning induced higher incidence of petechial haemorrhages in duck liver, whereas in geese, incidence of superficial haemorrhages was significantly higher after CAS and water-bath stunning. The calculation of an overall score based on the incidence and severity of the different appearance defects observed in the present experiment showed that CAS was associated with the least favourable position in ducks as well as in geese, compared to the other treatments. The commercial grading of ducks and geese fatty livers, carried out by an expert from the industry, clearly showed the detrimental effect of CAS on the commercial value of raw livers. CAS, under the conditions applied in the present work cannot be recommended, because of its drastic effect on liver quality. The underlying mechanisms deserve further investigations.     

Allele Distributions and Frequencies of the Six Prion Protein Gene (PRNP) Polymorphisms in Asian Native Cattle, Japanese Breeds, and Mythun (Bos frontalis)

Six polymorphic sites of the bovine prion protein gene (PRNP) were genotyped in 569 animals of Asian native cattle, Japanese breeds, purebred mythun (Bos frontalis), and mythun × cattle composite animals. At the 23-bp indel site, a deletion (23?) allele was a major allele in all populations except mythun. At the 12-bp indel site, an insertion (12+) allele was a major allele in all populations. The 14-bp indel site was polymorphic in all Asian native cattle. In the octapeptide repeat region, a six-repeat allele was a major allele in all populations, and 5/5 and 4/6 genotypes were detected in Japanese Black and Mongolian cattle and in mythun, respectively. Two nonsynonymous single nucleotide polymorphisms (SNPs) (K3T and S154N) were detected in Asian native cattle and mythun. Haplotype analysis using the genotypes of the six sites estimated 33 different haplotypes. The haplotype 23? 12? K 6 S 14+ was found in all populations.     

Molecular dynamics studies on the structural stability of wild-type dog prion protein

Prion diseases such as Creutzfeldt-Jakob disease, variant Creutzfeldt-Jakob diseases, Gerstmann-Str?ussler-Scheinker syndrome, Fatal Familial Insomnia, Kuru in humans, scrapie in sheep, bovine spongiform encephalopathy (or 'mad-cow' disease) and chronic wasting disease in cattle are invariably fatal and highly infectious neurodegenerative diseases affecting humans and animals. However, by now there have not been some effective therapeutic approaches to treat all these prion diseases. In 2008, canine mammals including dogs (canis familials) were the first time academically reported to be resistant to prion diseases (Vaccine 26: 2601-2614 (2008)). Thus, it is very worth studying the molecular structures of dog prion protein to obtain insights into the immunity of dogs to prion diseases. This paper studies the molecular structural dynamics of wild-type dog prion protein. The comparison analyses with rabbit prion protein show that the dog prion protein has stable molecular structures whether under neutral or low pH environments. We also find that the salt bridges such as D177-R163 contribute to the structural stability of wild-type rabbit prion protein under neutral pH environment.     

The effects of stunning methods on product qualities in force-fed ducks and geese. 1. Carcass downgrading and meat quality

This study investigated the effects of various stunning methods on the quality of carcass and meat in ducks and geese force-fed for the production of French 'foie gras'. The ducks (n = 30 per group) were stunned with one of the following techniques: electrical stunning in a water bath (50 Hz AC, 130 mA, 4 s), head-only electrical stunning (50 Hz AC, 600 mA, 4 s), mechanical stunning (captive bolt) and controlled atmosphere stunning (CAS: phase 1, CO2 (40%)-O2 (30%)-N2 (30%), for 2 min followed by phase 2, CO2 > 85% in air, for 2 min). The same methods (except head-only stunning which was not applied) were used in geese (n = 40 per group). During the first 5 min after slaughter, the stunning techniques that did not kill the animals were associated with a high incidence of head movements (mechanical and electrical head-only stunning), convulsions and convulsive wing flapping (mechanical stunning), in both species. Consequently, the rate of post-mortem pH fall in breast muscle was enhanced and the meat was paler when measured at 24 h or 6 days post mortem (L*, a*, b* coordinates). In ducks, the animals stunned in the water bath showed the lowest bleeding efficiency, compared to the three other procedures. In geese, the mechanical stunning allowed the highest recovery of blood compared to the CAS and the water-bath methods. Meat texture assessed instrumentally and fluid losses during storage and processing were not affected by the stunning method in any species. Sensory analysis showed a higher score for bloody appearance of raw meat in ducks stunned with the methods that kill before neck cutting (water-bath and CAS). This effect was, however, not linked to the rate of bleeding. The sensory properties of cooked meat were not affected by the stunning method. In both ducks and geese, CAS was associated with the lowest rate of fractures of humeral bone but CAS-stunned geese showed the most engorged wing veins. Overall, these results show the positive effect of CAS on the appearance defects of carcass and meat of ducks and geese, and, on the contrary, they confirm the detrimental effects of water-bath stunning on these criteria. However, the incidences on meat sensory qualities were scarce.     

Religious slaughtering: Implications on pH and temperature of bovine carcasses

The main objective of this study was to investigate the influence of different types of slaughtering on the variations of pH and temperature. Ninety entire male beef cattle, belonging to the Charolais breed, were distributed in three groups based on method of slaughtering. A total of 30 subjects (group K) were slaughtered without stunning, according to the Koscher rite; thirty bovines (group T) were stunned with a captive bolt gun, following the common slaughtering reported by Council Regulation (EC) 1099/2009; other thirty animals (group H) were slaughtered without stunning, based on Halal procedures. The temperature and pH values of carcasses were determined at 3, 6 and 24 h post-mortem, respectively. At 24 h post-mortem of the 30 carcasses evaluated for each group, muscle temperature decreased in all three types of slaughtering. In particular, the average temperature was 4.0, 4.9 and 3.0 °C for traditional, Halal and Koscher slaughtering, respectively. Moreover, at the same time step (24 h post-mortem), muscle pH decreased showing values equal to 5.72, 5.83, 5.81 for traditional, Halal and Koscher slaughtering, respectively. The findings of the present study may be useful to highlight the influence of slaughtering method on pH and, more generally, on meat quality. Additionally, our results show that, in slaughtering carried out without prior stunning, the carcass could be more susceptible to alterations because of the high pH values.