Time to collapse following slaughter without stunning in cattle

Time to physical collapse was examined in 174 cattle which were restrained in the upright position and then released immediately from the restraint following the halal cut. The frequencies of swelling and false aneurysm in the cephalic and cardiac severed ends of the arteries were recorded. Fourteen percent of the cattle collapsed and stood up again before finally collapsing. The average time to final collapse for all the cattle was 20 s (sd ± 33). In 8% of the animals time to final collapse was ?60 s. Seventy-one percent of the cattle that took more than 75 s to collapse had false aneurysms in the cardiac ends of the severed carotid arteries. The frequency of swelling at the cephalic severed ends of the carotid arteries in 129 cattle was 7%. Failure to collapse within 60 s was associated with swelling of the cephalic ends of the carotid arteries.     

False aneurysms in carotid arteries of cattle and water buffalo during shechita and halal slaughter

It has previously been shown that the cattle brain is supplied with blood via a basi-occipital plexus, in addition to branches from the carotid and basilar arteries. In addition it has been shown during conventional stunning and slaughter that the carotid arteries in cattle can develop false aneurysms at their severed ends and this can curtail exsanguination. This investigation examined whether false aneurysms can occur during religious slaughter, and during bleeding following electrical stunning that simultaneously induced a cardiac arrest. The prevalence of large (>3 cm outer diameter) false aneurysms in cattle carotid arteries was 10% for both shechita and halal slaughter. The prevalence of animals with bilateral false aneurysms (at least 2 cm in one artery and at least 3 cm diameter in the opposite artery) was 7% and 8% for shechita and halal slaughter, respectively. No false aneurysms occurred during bleeding in cattle that were electrically stunned and simultaneously developed a cardiac arrest. The combination of false aneurysms and collateral routes to the brain present a risk of sustained consciousness during religious slaughter in cattle.     

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

Previous work in calves indicated that ballooning of the severed arteries is a potential concern in animals receiving a reversible stun before slaughter, and in animals not stunned before slaughter, as it could extend the duration of brain function before the animals die. This study determined the prevalence of ballooning of the carotid arteries in a total of 987 cattle, calves and lambs at slaughter. The severed ends of the carotid arteries were examined by palpation. The prevalence of ballooning that was 3 cm or more in diameter, was 16%, 25% and 0% for cattle, calves and lambs, respectively. Artery sections were taken from a sample of large cattle and examined histologically. In ballooned arteries there was coagulated blood between the outer surface of the artery and the inner aspect of the connective tissue sheath surrounding the artery, suggesting the formation of a false aneurysm in the ballooning phenomenon.     

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

Previous work in calves indicated that ballooning of the severed arteries is a potential concern in animals receiving a reversible stun before slaughter, and in animals not stunned before slaughter, as it could extend the duration of brain function before the animals die. This study determined the prevalence of ballooning of the carotid arteries in a total of 987 cattle, calves and lambs at slaughter. The severed ends of the carotid arteries were examined by palpation. The prevalence of ballooning that was 3 cm or more in diameter, was 16%, 25% and 0% for cattle, calves and lambs, respectively. Artery sections were taken from a sample of large cattle and examined histologically. In ballooned arteries there was coagulated blood between the outer surface of the artery and the inner aspect of the connective tissue sheath surrounding the artery, suggesting the formation of a false aneurysm in the ballooning phenomenon.     

Religious slaughter: Evaluation of current practices in selected countries

As part of the project “Religious slaughter (DIALREL): improving knowledge and expertise through dialogue and debate on issues of welfare, legislation and socio-economic aspects”, this paper discusses an evaluation of current practices during Halal and Shechita slaughter in cattle, sheep, goats and poultry. During religious slaughter, animals are killed with and without stunning by a transverse incision across the neck that is cutting the skin, muscles (brachiocephalic, sternocephalic, sternohyoid, and sternothyroid), trachea, esophagus, carotid arteries, jugular veins and the major, superficial and deep nerves of the cervical plexus. In this report, the restraint methods, stunning, neck cutting, exsanguination, slaughter techniques and postcut handling in the abattoir were assessed for religious slaughter. Information about the procedures used during religious slaughter in Belgium, Germany, Italy, the Netherlands, Spain, the UK, Turkey and Australia was collected by means of spot visits to abattoirs. To standardize the information gathered during the spot visits three guidelines were designed, one for each species, and translated into the national languages of the countries involved. The document included questions on the handling and restraint methods (stunning, neck cutting/exsanguination/slaughter techniques and postcut handling performed under religious practices) and for pain and distress of the animal during the restraint, neck cutting and induction to death in each abattoir. Results showed differences in the time from restraining to stun and to cut in the neck cutting procedures and in the time from cut to death.     

Welfare of calves - 2. Increase in vertebral artery blood flow following exsanguination by neck sticking and evaluation of chest sticking as an alternative slaughter method

The role of the vertebral arteries in delaying loss of sensibility following neck sticking in slaughter calves was investigated. Vertebral artery blood flow was measured using probes before, during and after electrical stunning and slaughter. Systemic blood pressure, electrocorticogram, visually evoked responses and the occurrence of carotid occlusions were also recorded. When carotid occlusion occurred, the time to onset of brain failure was delayed based on the development of an isoelectric state. In addition, when carotid occlusion occurred the mean arterial blood pressure was sustained for longer following slaughter, and concurrently vertebral artery blood flow could be maintained at about 30% of its initial level for up to 3 min. In some animals vertebral artery flow increased substantially following sticking. When chest sticking was used no occlusion of vessels occurred, mean arterial blood pressure fell promptly (within 8 s) and the onset of an isoelectric state did not extend beyond one minute. In addition, visually evoked responses were not present after 5 s following chest sticking.     

Jugular blood flow in calves after head-only electrical stunning and throat-cutting

Jugular flow was measured after head-only electrical stunning and gash cutting in 12 calves less than a week old. Jugular flow was assumed to provide a crude measure of cerebral perfusion during exsanguination. In 10 animals the average amount of jugular blood collected within 1-2 min of throat-cutting was the equivalent of a total cerebral blood flow of 3·6 ml/min/100 g ± 1·4 SD or 4·8% of normal. In two animals the jugular flow was increased to 39% and 22% of normal cerebral flow. All animals had strong retrograde flow from the head ends of the cut carotid arteries. The dynamics of cerebral blood perfusion are discussed with reference to systemic arterial blood pressure and spontaneous cortical electrical activity, and some potentially fruitful areas of research on the humaneness of halal slaughter of cattle are proposed.     

Rate of blood loss and timing of exsanguination on prevalence of ecchymosis in fallow deer (Dama dama)

Blood loss associated with four combinations of stunning and exsanguination methods was determined as part of studying prevalence of ecchymosis in slaughtered fallow deer (Dama dama). A fifth treatment simulated incomplete severance of the extended neck after captive bolt stunning. Predicted mean weights of blood collected from the five slaughter treatments, including electrical stunning followed by the thoracic stick method of exsanguination, captive bolt stunning followed by the thoracic stick, captive bolt stunning followed by the gash cut method of exsanguination, electrical stunning followed by the gash cut, and captive bolt stunning followed by incomplete severance of the extended neck, were 1458.7, 1072.7, 684.5, 463.7, and 228.5 g, respectively. The overall effect of exsanguination method was highly significant (p < 0.001) with the thoracic stick resulting in the greatest weight of blood collection in the 10 s period immediately after initiation. The overall effect of stunning method on blood loss was not significant, although there was a significant (p < 0.05) stunning method by exsanguination method interaction. Ecchymosis of varying severity occurred in some carcases from all treatment groups. Using the total loin and round ecchymosis scores, when little or no ecchymosis (grades 0 or 1) was compared with some ecchymosis (?grade 2) by logistic regression, castrated bucks were 9.8 times more likely (p = 0.002) and does 4.2 times more likely (p = 0.06) to have some ecchymosis than entire bucks. The results indicate that ecchymosis can be reduced in fallow deer carcases by thoracic stick exsanguination incorporated less than 10 s after stunning.     

Blood in the respiratory tract during slaughter with and without stunning in cattle

Bovine respiratory tracts were examined for blood following shechita without stunning, halal slaughter without stunning, and captive bolt stunning with sticking. In all three methods the cattle were in the upright (standing) position at the start of bleeding. Those that had not been stunned continued to breathe during the early part of bleeding whilst those that were stunned were not breathing. Nineteen percent of the shechita, 58% of the halal and 21% of the stunned plus stuck cattle had blood lining the inner aspect of the trachea. Thirty six percent, 69% and 31% had blood in the upper bronchi, respectively. Ten percent, 19% and 0% had fine bright red blood-tinged foam in the trachea, respectively. It was concluded that concerns about suffering from airway irritation by blood could apply in animals that are either not stunned before slaughter or do not lose consciousness rapidly whilst blood is present in the respiratory tract.     

The relationship between exsanguination blood lactate concentration and carcass quality in slaughter pigs

A group of 128 cross-bred barrows were used to determine the relationship between exsanguination blood lactate concentration ([LAC]) and carcass quality following commercial marketing conditions. After 10 h of feed withdrawal, pigs were loaded on a truck with a hydraulically lifted second deck and transported approximately 1 h to the slaughter facility. Pigs were rested for 8 h and stunned with carbon dioxide. Blood lactate concentration was measured on exsanguination blood. Fourteen pork quality measurements were obtained following normal post-mortem processing. Pearson correlations were used to determine the relationships between [LAC] and the meat quality parameters. Exsanguination blood lactate concentration ranged from 4 to 19.7 mM. Higher lactate was associated with lower 60 min pH (P = 0.0004) and higher drip loss (P = 0.02). These results suggest that under low-stress loading and standard marketing conditions, exsanguination [LAC] is predictive of the rate of early post-mortem metabolism.     

Animal welfare at markets and during transport and slaughter

This review highlights some recent developments in our understanding of stress and physical injuries that occur before and during transport to slaughter, during handling at livestock markets, and at the time animals are put-up for slaughter within abattoirs. Stress in pigs during transfer to the stunning point within the abattoir has important effects on meat quality, and there is growing evidence that strenuous exercise or CO(2) stunning can contribute to oxidative rancidity in pigs, poultry and fish. In the EU, putting cattle through a crush in order to check that their eartag numbers correspond to their passport numbers is imposing additional stress, and there are reports that it is leading to greater hide contamination with Escherichia coli O157. Recent developments in stunning and slaughter include a better understanding of the causes of variation in captive bolt gun performance, the effectiveness of poll instead of frontal shooting in water buffalo, the prevalence of false aneurysms in carotid arteries during shechita and halal slaughter, and the stress effects of CO(2) stunning in fish. Stunning pigs with 90% CO(2) leads to less PSE meat than 80% CO(2). There have been concerns about the physical activity that cattle show following electrical stunning with an electrically induced cardiac arrest, and with electrical stunning using DC waveforms in broiler chickens. There is also growing concern about the hygiene problems that exist in wet markets, where animals are slaughtered alongside meat that is on display to customers.     

Tenderness enhancement of beef from Bos indicus and Bos taurus cattle following electrical stimulation

High voltage electrical stimulation (1130 V peak, 14.28 bidirectional half sinusoidal pulses/s) or low voltage stimulation (45 V peak, 36 alternating square wave pulses/s) was used on cattle: (1) low voltage stimulation applied for 10 or 40 s with fast and slow chilling or high voltage stimulation for 60 s with normal chilling, applied to 100% Bos taurus cattle, (2) low voltage stimulation (40 s) and high voltage stimulation (60 s) with normal chilling applied to mixed Bos indicus and B.taurus cattle, (3) high voltage stimulation (54 s) with normal chilling applied to B. taurus and B. indicus cattle of 0–100% B. indicus composition, and (4) high voltage stimulation (60 s) applied to 100% B. taurus and 100% B. indicus cattle. All stimulation parameters enhanced the tenderness of steaks from M. longissimus thoracis et lumborum (LTL) aged at 1 °C up to 28 days compared with non stimulated LTL. Short low voltage stimulation of 10 s was marginally more effective than no stimulation and longer durations of 40 s were very effective and high voltage stimulation was most effective.     

Color Doppler flow imaging for the early detection of nonpregnant cattle at 20 days after timed artificial insemination

The objective was to determine the accuracy of a pregnancy test for predicting nonpregnant cattle based on the evaluation of corpus luteum (CL) blood flow at 20 d (CLBF-d20) after timed artificial insemination (TAI). Crossbred Holstein-Gir dairy heifers (n = 209) and lactating cows (n = 317) were synchronized for TAI using the following protocol: intravaginal implant (1.0 g of progesterone) and 2 mg of estradiol benzoate i.m. on d −10, implant removal and 0.526 mg of sodium cloprostenol i.m. on d −2, 1 mg of estradiol benzoate i.m. on d −1, and TAI on d 0. On d 20, animals underwent grayscale ultrasonography (US) to locate the CL and color flow Doppler to evaluate CLBF-d20 using a portable ultrasound equipped with a 7.5-MHz rectal transducer. Based only on a visual, subjective CLBF evaluation, the animals were classified as pregnant or not pregnant. On d 30 to 35, blinded from results of the previous diagnosis, the same operator performed a final pregnancy diagnosis using US to visualize the fetal heartbeat (gold standard; US-d30). A second evaluator also analyzed the CLBF-d20 in the same animals by watching 7-s recorded videos. Blood samples were collected from a subset of 171 females to determine, by RIA, plasma progesterone (P₄) concentrations, which indicate CL function. The final pregnancy outcome (US-d30) was retrospectively compared with the CLBF-d20 diagnoses and then classified either as correct or incorrect. The number of true positive, true negative, false positive, and false negative decisions were inserted into a 2 × 2 decision matrix. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the CLBF-d20 test were calculated using specific equations. Binomial variables (pregnancy rate and proportions) were analyzed using Fisher’s exact test for the effect of parity and to compare between evaluators and tests (CLBF-d20 vs. plasma P₄). The kappa values were calculated to quantify the agreement between CLBF-d20 and the gold standard (US-d30) and between evaluators. The performance parameters of CLBF-d20 test were as follows: sensitivity = 99.0%, specificity = 53.7%, positive predictive value = 65.1%, negative predictive value = 98.5%, and accuracy = 74.8%. False negatives represented only 0.4% of the exams. No differences existed in these parameters between evaluators (no. 1 vs. no. 2) and tests (CLBF-d20 vs. plasma P₄). Moreover, a high level of agreement was observed between evaluators (0.91). In conclusion, visual evaluation of CLBF-d20 represents a quick, reliable, and consistent diagnostic test that enables the early detection of nonpregnant cattle.     

Glucagon-like peptide-2 (GLP-2) increases small intestinal blood flow and mucosal growth in ruminating calves

Glucagon-like peptide-2 (GLP-2) increases small intestinal mass and blood flow in nonruminants but its effect in ruminants is unknown. Eight Holstein calves with an ultrasonic flow probe around the superior mesenteric artery and catheters in the carotid artery and mesenteric vein were paired by age and randomly assigned to treatment of a control (0.5% of BSA in saline; n = 4) or GLP-2 (50 μg/kg of body weight of bovine GLP-2 in BSA; n = 4) given subcutaneously every 12 h for 10 d. Blood flow was measured on d 0 (acute) and d 10 (chronic) and included 3 periods: baseline (saline infusion), treatment (infusion of BSA or 1,000 pmol of GLP-2/kg of body weight per h), and recovery (saline infusion). On d 11, calves were killed 2 h after injection of 5-bromo-2′-deoxyuridine (BrdU). Gastrointestinal tissues were weighed and epithelial samples were obtained to determine villus height, crypt depth, and BrdU staining. Infusion of GLP-2 increased superior mesenteric artery blood flow to 175% of baseline on d 0 but to only 137% of baseline after chronic treatment. Compared with that of the control, GLP-2 increased small intestinal mass by 24% by increasing epithelial mass in the jejunum and ileum. Additionally, GLP-2 increased villus height, crypt depth, and BrdU-labeling in small intestinal segments. These results demonstrate that GLP-2 induces similar increases in small intestinal blood flow and growth in ruminants to those observed in nonruminants. Furthermore, GLP-2 increases small intestinal blood flow in ruminants but this response is attenuated after 10 d of GLP-2 administration. In cattle, GLP-2 may be an important hormone in the regulation of intestinal blood flow and epithelial growth.     

Seasonal changes and muscle type effect on the nutritional quality of intramuscular fat in Mirandesa-PDO veal

The influence of slaughter season and muscle type on the detailed fatty acid composition, including conjugated linoleic acid isomers, and contents of total cholesterol and lipid-soluble antioxidant vitamins (α-tocopherol and β-carotene) in Mirandesa-PDO veal was assessed. Mirandesa purebred calves (n = 29) were raised in a traditional production semi-extensive system, slaughtered in late spring (June) or early autumn (October) and the longissimus lumborum and semitendinosus muscles were sampled for analysis. Although the lipid composition of PDO veal was only slightly affected by the slaughter season, it was markedly changed by the muscle type. However, PDO veal had values of pasture-fed cattle for lipid grass intake indicators, in both seasons and muscles. From a human health standpoint, intramuscular fat in Mirandesa-PDO veal has a high nutritional value throughout the year, with favorable ratios of n− 6/n− 3 and contents of n− 3 PUFA and α-tocopherol, as a result of the beneficial effects of grass feeding.     

Effects of genotype and slaughter weight on the meat quality of Criollo Cordobes and Anglonubian kids produced under extensive feeding conditions

Physicochemical and organoleptic characteristics of meat (longissimus muscle) from Criollo Cordobes (CC) and Anglonubian (AN) suckling kids were analysed to determine the effects of genotype and slaughter weight. Forty suckling entire male kids, 20 CC and 20 AN were assigned to two age/slaughter weight groups (I: 60 + 2 days old and ?11 kg, and II: 90 + 2 days old and >11 kg). Colour, shear force and cholesterol levels of meat were affected by breed. Tenderness decreased and cholesterol increased with age/slaughter weight. Fatty acid profiles were affected primarily by genotype. The sensory attributes were perceived as medium-high intensity, and meat from CC and AN goat kids was valued as tender. However, initial tenderness and connective tissue varied with genotype. The main effect due to the increase in age/slaughter weight was a decrease in tenderness (initial and overall), as observed for instrumental shear force.     

Effect of fasting on energy metabolism and tenderizing enzymes in chicken breast muscle early postmortem

Pre-slaughter fasting is a very important practice in the meat industry. The present study was designed to investigate the effect of fasting on energy metabolism and tenderizing enzymes in chicken muscle early postmortem. A total of 30 Yellow-feathered chickens were deprived of feed for 0 h, 12 h and 24 h before slaughter (n = 10 each group). Breast muscles were removed and cut into 3 parts and stored at 0 °C for 0 h, 3 h and 10 h. Samples were used for analyses of zymography, cathepsins, pH, glycogen/ATP/ADP/AMP, hormones and ultrastructure. Fasting caused the accelerated depletion (p < 0.05) of glycogen, ATP and ADP before or immediately after slaughter, but no difference existed in ATP at 3 and 10 h (p > 0.05). Fasting resulted in greater ultimate pH (p < 0.05). Zymography indicated that fasting delayed the activation of μ/m-calpain (p < 0.05), however, it accelerated the release of lysosomal enzymes (p < 0.05). Fasting for 24 h resulted in greater ultrastructural changes and plasma corticosterone levels than fasting for 12 h and control groups. Therefore, fasting for no more than 12 h is acceptable in practice.     

Moisture and fat content,marbling level and color of boneless rib cut from Nellore steers varying in maturity and fatness

This study analyzed rib steaks (M. longissimus thoracis) of Nellore steers (n = 60) for intramuscular moisture and fat content, marbling level, and visual and instrumental color. Carcass sides were classified on the kill floor according to teeth maturity (2, 4 and 6 permanent incisors), and fatness (2 — slight and 3 — average). The cranial end of the boneless cut was aged for 14 days, and frozen. Steaks of 2.5 cm thick were cut and thawed for analysis. Moisture and fat content were determined in minced lean. CIE color was measured with a MiniScan XE™, and visually evaluated by an eight-member panel, which also assessed marbling. In this type of cattle and ranges of maturity and fatness considered, increasing either maturity or fatness causes a slight reduction in moisture and an increment in lipid content. But neither maturity nor fatness seems to affect the visual perception of meat color on display.     

Welfare of calves - 1. Investigations into some aspects of calf slaughter

The relationship between carotid occlusion, systemic blood pressure and brain function following electrical stunning and exsanguination (sticking) in slaughter calves (< 10 weeks) was assessed. Electrocorticograms, systemic blood pressure and evoked responses were measured in the chloralose. anaesthetised and the unanaesthetised states. Electrical stunning produced relatively short periods of measurable epilepsy in slaughter calves (18 s average). The pattern of decline in blood pressure after sticking showed variations between animals. However, the results indicated that two groups of animals could be recognised: a carotid occlusion (ballooning group) and no carotid occlusion (non-ballooning) group. The animals with ballooning (six out of 15 = 40%) developed occlusions of the caudal severed ends of the carotid arteries. These swellings, the so-called 'ballooning' effect, were characterised by large clots forming plugs at the severed ends of the arteries. When this phenomenon occurred the haemorrhaging was clearly impeded. This was reflected in the blood pressure traces which showed recovery episodes coinciding with the occurrence of the carotid occlusions. Our study indicates that in the worst possible case the development of a restriction to the outflow of blood can delay the rate of haemorrhaging and the decline in blood pressure. This can lead in turn to sustained brain function as evidenced by the continued presence of evoked responses following stun recovery and a long time to onset of the isoelectrical state in the electrocorticogram.     

Influence of neck-rail placement on free-stall preference, use, and cleanliness

Three experiments examined how the presence of a neck rail at different heights and locations influenced dairy cattle behavior and stall cleanliness. Experiment 1 compared 4 levels of neck-rail height (102, 114, and 127 cm and no neck rail; presented at 160 or 180 cm from the curb) in a preference test. Cows (n = 10) showed no consistent preference based on neck-rail height, regardless of the horizontal position of the neck rail. When cows were restricted to each treatment in turn, however, time spent standing fully (with all 4 hooves) in the stall was least in the stall with the lowest neck rail (mean, 22 min/24 h) and was greatest in the stall with no neck rail (mean, 83 min/24 h). A second experiment examined the effect of a neck rail placed at 3 distances from the curb (140, 175, and 233 cm) when height was held constant (131 cm; n = 12). Time spent standing fully in the stall was least when the neck rail was close to the curb (140 cm; mean, 11 min/24 h) and was greatest when the neck rail was furthest from the curb (233 cm; mean, 86 min/24 h). When the neck rail was far from the curb, the cows were more likely to soil the stall by defecating while standing fully in the stall. Experiment 3 compared soiling of the stall by 14 cows with and without a neck rail at a height of 124.5 cm. When the neck rail was removed, cows were more than twice as likely to soil the stall by defecating while standing fully in the stall compared with when the neck rail was present (1.3 vs. 0.5 defecations/24 h). Thus, restrictive neck-rail placement prevents cows from standing in stall, but helps keep stalls clean. Access to more comfortable flooring surfaces outside the stall may help mitigate the negative effects of restrictive neck rails.