Auditing animal welfare at slaughter plants

The OIE Welfare Standards on slaughter transport, and killing of animals for disease control are basic minimum standards that every country should follow. The OIE, European Union, and many private standards used by commercial industry have an emphasis on animal based outcome standards instead of engineering based standards. Numerical scoring is used by both private industry and some governments to access animal welfare at slaughter plants. Five variables are measured. They are: 1) Percentage of animals effectively stunned on the first attempt, 2) Percentage rendered insensible, 3) Percentage that vocalize (bellow, moo, squeal) during handling and stunning, 4) Percentage that fall during handling, and 5) Percentage moved with an electric goad. Each one of these critical control points measures the outcome of many problems. A good animal welfare auditing system also has standards that prohibit really bad practices such as dragging, dropping, throwing, puntilla, and hoisting live animals before ritual slaughter. On farm and transport problems that can be measured at the slaughter plant are: percentage of lame animals, percentage of thin animals, percentage of dirty animals, percentage with sores, bruises or lesions, death losses, morbidity, and percentage of birds with broken wings and legs.     

Effects of mid-summer transport duration on pre- and post-slaughter performance and pork quality in Mexico

Seven hundred and fourteen pigs were monitored from transport to slaughter in July in three treatments: 8, 16 and 24 transport hours; lairage time for the three groups was of 8h. Transport duration significantly (P<0.05) affected live-weight gain during the rest period. Weight gain percentages at lairage were 0.05%, 0.78% and 1.15% for treatments 1, 2 and 3, respectively. Transport to slaughter loss percentage was 2.7%, 4.3% and 6.8% for each of the treatments. Short transport periods significantly increased carcass pH below normal values. Animals transported under acute stress (8h) showed pale carcasses (high possibilities of transforming into PSE meat). On the contrary, pigs transported for 24h had more dark red carcasses. Transport from farm to the slaughterhouse should take no more than 16h in order to improve carcass quality and animals' welfare.     

Stunning and animal welfare from Islamic and scientific perspectives

The transformation of an animal into pieces fit for human consumption is a very important operation. Rather than argue about halal slaughter without stunning being inhumane or stunning being controversial from the Islamic point of view, we discuss slaughter, stunning and animal welfare considering both Islamic and animal welfare legislation requirements. With the world Muslim population close to two billion, the provision of halal meat for the Muslim community is important both ethically and economically. However, from the animal welfare standard point of view, a number of issues have been raised about halal slaughter without stunning, particularly, about stressful methods of restraint and the latency of the onset of unconsciousness. This paper sets out to, discuss the methods of stunning that are acceptable by Islamic authorities, highlight the requirements for stunning to be acceptable in Islam and suggest practical ways to improve the humanness of slaughter.     

Causes of cattle bruising during handling and transport in Namibia

Numerous risks associated with transport and handling of livestock cause bruising and poor welfare to animals. Variables having an influence on the level of bruising under Namibian transport conditions include animal factors (breed type, age, sex, condition and subcutaneous fat cover), pre-transport handling (re-branding of animals), transport related risks (loading density, animals lying down during transit) and lairage factors (fit of truck floor to off-loading ramp, moving to holding pen, pen size and minimum temperatures). Although no single factor was the dominant driver of bruise prevalence; load density, gravel roads, and cattle running after disembarking had a cumulative effect on bruising. Surprisingly, transport duration (3 vs 8h) had minimal effect. The overall incidence of bruising is high, with the highest levels on the hips, around the butt and pin areas. In the event of animals transported to slaughter in the central areas of Namibia, conditions surrounding transport are more important than the distance transported or journey duration.     

Effect of transport time on welfare and meat quality in pigs

The purpose of this study was to determine the effects of transport duration on some welfare and meat quality parameters. For the study 144 pigs were used. One group of 72 animals was subjected to 15 min and the others to 3 h transport time. Blood from all animals was analysed in order to detect stress-susceptible pigs and assess pre-slaughter stress. Meat quality parameters were analysed from Longissimus thoracis and Semimembranosus muscles. It was concluded that under normal Spanish commercial conditions, pigs subjected to short transport showed a more intense stress response and poorer meat quality than pigs subjected to moderately long transport when they were immediately slaughtered on arrival at the slaughterhouse. Transport of 3 h might have allowed the animals to adapt to transport conditions and then could act as a resting period like a lairage time. The effect of transport time on welfare and meat quality parameters was more important than genotype and sex. Nevertheless, from the point of view of blood enzyme activities, genetically stress susceptible females transported for 3 h were more sensitive to muscle damage.     

Explaining and predicting differences in meat quality through stress reactions at slaughter: The case of Large White and Duroc pigs

Large White and Duroc pigs (n=42) were group-reared on straw. Durocs were more active in the home pens and had higher basal urinary cortisol levels. During tests, Durocs touched more often an unfamiliar human, but not an unfamiliar object, than Large Whites. Pigs were experimentally (low stress) or industrially (high stress) slaughtered. Meat (Longissimus lumborum (LL), Biceps femoris (BF), Adductor femoris (AF) and Semimembranosus (SM)) was darker, more yellow, had higher ultimate pH and better water holding capacity after high, compared to low-stress slaughter. Large White meat contained less pre-slaughter glycogen, was redder and lost more drip. Slaughter conditions influenced ultimate pH of Large White more than of Duroc meat. Large Whites, and to a lesser extent Durocs, touching the human less often during the test, had faster early post-mortem LL and BF muscle metabolism. Pigs exploring the unfamiliar object more often were more aggressive during pre-slaughter mixing and had higher AF and SM ultimate pH.     

Animal welfare assessment at slaughter in Europe: moving from inputs to outputs

Producers, retailers and other food chain actors increasingly recognize that consumer concerns for good animal welfare represent a business opportunity that could be profitably incorporated into their commercial strategies. Therefore, during the last decade, numerous trade groups (producers, processors, retailers and restaurant chains) have developed certification systems with their suppliers which include elements of animal welfare. The Welfare Quality® project has developed an integrated and standardised welfare assessment system based on twelve welfare criteria grouped into four main principles (good feeding, good housing, good health and appropriate behaviour) according to how they are experienced by animals. One of the innovations of the Welfare Quality® assessment system is that it focuses more on outcome measures (e.g. directly related to animal body condition, health aspects, injuries, behaviour, etc.). This paper has the objective to discuss the rationale behind the welfare assessment and to describe the Welfare Quality® assessment of pigs and cattle at the slaughterhouse.     

Bayesian meta-analysis of the effect of fasting, transport and lairage times on four attributes of pork meat quality

Technological meat quality is a significant economic factor in pork production, and numerous publications have shown that it is strongly influenced both by genetic status and by rearing and slaughter conditions. The quality of meat is often described by meat pH at different times postmortem, as well as by color and drip loss. A meta-analysis based on a database built from 27 studies corresponding to a total of 6526 animals classified was carried out. The purpose of this meta-analysis was to study the effect of fasting, lairage and transport durations on four main attributes of the technological pork meat quality. A Bayesian hierarchical meta-regression approach was adopted.The results of our meta-analysis showed that fasting time had a significant effect on pH measured 24 h post-mortem (pHu) and drip loss (DL) measured in longissimus muscle. While, lairage affected only the pHu in semimembranosus muscle. Interestingly, we found that DL was the lone attribute that was affected by transport time and its interaction with fasting time.     

Animal welfare and meat quality: The perspective of Uruguay,a “small” exporter country

Public sensitivity towards animal welfare has risen in recent years. Uruguay is a primary meat exporter. Therefore, it is compulsory not only to provide good quality and safe meat, but also to project a welfare friendly image. Uruguayan meat production systems are mainly based on rangeland pastures but, due to international meat prices and the opening of new markets, intensive fattening systems increased. These systems include a wide range of feeding alternatives between pasture and concentrate utilization, involving differences in terms of animal welfare, carcass and meat quality, that require to be studied. Accordingly, some husbandry practices associated mainly with extensive systems must be evaluated, as well as their applicability to international recommendations related to pre-slaughter handling which may not be suitable for local conditions. In the present paper we share scientific results related to the impact of different production systems, husbandry practices and pre-slaughter procedures associated to animal welfare and meat quality in Uruguayan conditions.     

Effects of weight at slaughter and sex on the carcass characteristics of Florida suckling kids

The effect of slaughter weight and sex on some carcass traits of suckling kids of the Florida breed was evaluated. A total of 60 kids (30 male and 30 female), fed exclusively on milk replacers, were slaughtered at 7-8kg (group 1), 10-11kg (group 2) or 14-15kg (group 3) of liveweight (mean weights of 7.6kg, 10.8kg and 14.4kg, respectively). Higher slaughter weights decreased the percentage of subproducts (blood, skin, head, feet) and internal organs (lungs+traquea, heart, liver, spleen, thymus) but significantly increased the percentage of intestine and fat depots (omental fat and mesenteric fat). Higher slaughter weights also increased carcass measures (L 40.5 vs 49.1; F 22.5 vs 25.9; G 10.4 vs 14.2; Wr 10.1 vs 13.9; Wth 8.0 vs 10.5; Th 16.5 vs 199; B 32.3 vs 42.4; PT 41.5 vs 50.8), compactness carcass index (96.6 vs 152.3) and compactness leg index (27.5 vs 44.1). Sex only significantly affected the percentages of feet, internal organs, omental fat, measure L, carcass compactness index and hind limb compactness index. The meat colour and fat colour were mainly scored as pale and white respectively in the carcasses of the lightest animals, whereas heavier kids were scored as pink and cream. Slaughter weight also influenced significantly the carcass fatness (score 1 in lightest kids and 2 or 3 in heavier ones). There were no significant (p>0.05) differences between slaughter weight group and sex in dressing percentages. Percentages corresponding to the long leg, back and neck (30-33%, 18-19% and 8-10%, respectively) decreased when the slaughter weight increased, whereas the ribs (23-25%) and the flank (10-11%) increased slightly. The carcasses comprised 57-58% muscle, 22-25% bone, 5-6% subcutaneous fat and 9-12% intermuscular fat. The percentage muscle stayed the same with increasing slaughter weight, whereas the bone decreased and the fat increased. The carcasses of the heavier females contained less lean and more fat than the males. The bone percentage was significantly (p<0.05) lower in the females and the carcass fat percentage was significantly (p<0.05) higher than in the males.     

Animal welfare: An animal science approach

Increasing world population and demand for animal-derived protein puts pressure on animal production to meet this demand. For this purpose animal breeding efforts were conducted to obtain the maximum yield that the genetic makeup of the animals permits. Under the influence of economics which is the driving force behind animal production, animal farming became more concentrated and controlled which resulted in rearing animals under confinement. Since more attention was given on economics and yield per animal, animal welfare and behavior were neglected. Animal welfare which can be defined as providing environmental conditions in which animals can display all their natural behaviors in nature started gaining importance in recent years. This does not necessarily mean that animals provided with good management practices would have better welfare conditions as some animals may be distressed even though they are in good environmental conditions. Consumers are willing to pay more for welfare-friendly products (e.g.: free range vs caged egg) and this will change the animal production practices in the future. Thus animal scientists will have to adapt themselves for the changing animal welfare rules and regulations that differ for farm animal species and countries. In this review paper, animal welfare is discussed from an animal science standpoint.     

Effect of different stocking densities during transport on welfare and meat quality in Danish slaughter pigs

Four stocking densities (0.35, 0.39, 0.42 and 0.50 m² per 100 kg pig) were investigated under Danish early Autumn conditions (16–24 ° C) in a study of the effect of transport conditions on pig welfare and meat quality. Two transports were carried out for each stocking density, the two producers concerned delivering pigs to the upper and lower tiers, respectively, of a specialist pig transport vehicle. Total average journey time was 2 hr 39 min and total average transport time 1 hr 47 min. After arrival at the factory pigs were lairaged in groups of 15 for about hr and then slaughtered using minimal stress with group CO₂-stunning. Pig behaviour was monitored during transport in the front compartment of the lower tier. Blood samples were taken at slaughter for analysis of creatine phosphokinase, lactate and cortisol and carcasses were evaluated for skin damage and meat quality. Stocking density, as such, had relatively little effect on blood profile or meat quality. Creatine phosphokinase levels were lowest with a stocking density of 0.50 m² and the incidence of unacceptable skin damage was generally lowest with a stocking density of 0.35 m² and highest with 0.42 m². The main source of variation in this experiment was day of transport/slaughter within stocking density so that factors other than stocking density have affected the results obtained. Stocking density had a direct effect on pig behaviour during transport. Giving pigs more space during the short transport did not result in them lying down. On the contrary there was continuous disturbance from other pigs and at 0.42 and 0.50 m² pigs had difficulty maintaining balance, when the vehicle negotiated bends or poor road surfaces. Variations in pig behaviour during transport could account for the observed differences in skin damage.     

Effect of cardiac arrest at slaughter on residual blood content of hide

Inducing a cardiac arrest between stunning and sticking in cattle had no effect on the residual blood content of the hide. Skin from animals which had been dead for about 15 min, but not bled, contained twice as much blood as skin from animals slaughtered in a normal manner. It is concluded, therefore, that the fellmongering problems which are associated with excessive amounts of blood in the hide should not be a problem when stunning methods which simultaneously induce a cardiac arrest are used. This should hold true provided the animal is stuck promptly after it has undergone heart failure.     

Rest before slaughter ameliorates pre-slaughter stress-induced increased drip loss but not stress-induced increase in the toughness of pork

One factor affecting meat quality is pre-slaughter stress. We investigated the effects of exercise stress on drip loss and toughness in relation to resting times of 0, 1 or 3 h following exercise on a treadmill. This exercise stress was regarded as combined physical and physiological stress. Exercise stress increased the muscle temperature, reduced the creatine phosphate, ATP and glycogen content of pigs slaughtered immediately after stress exposure. These conditions lead to a reduced pH early post mortem and an increased drip loss, while only 1 h of rest after exercise stress normalised these effects. However, an overshooting effect was noted when pigs were rested for 1–3 h before slaughter, emphasising the importance of critical control of the resting period when studying exercise stress-induced effects on meat quality. Furthermore, meat from exercise stressed pigs, irrespective of resting, had increased toughness compared to controls, indicating that the toughness was not related to drip loss in meat from exercise stressed pigs.     

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.     

Influence of season, distance and mixed loads on the physical and carcass integrity of pigs transported to slaughter

To determine the influences of season, distance and multiple-farm loads on pigs transported to slaughter under Spanish commercial conditions, 496 journeys, involving 90,366 pigs, were analysed. Mortality, liveweight loss, transport yield, killing out percentage, carcass yield after overnight chilling and percentage of condemned and trimmed carcasses were recorded. Season significantly affected killing out percentage and trimmed carcasses, with the lowest values found in autumn and summer, respectively. Distance significantly affected liveweight loss and transport yield. Loads composed of pigs from a number of farms had more deaths and carcass problems. It can be concluded that, under Spanish climatic conditions, if journey planning and handling at loading are adequately performed, season and distance do not impair the welfare of slaughter pigs. On the other hand, loading at a number of farms, alone, or interacting with distance, can compromise pig welfare.     

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.     

Effect of lairage duration on rabbit welfare and meat quality

This study determined whether short (2 h) or long (8 h) lairage at an abattoir had an effect on plasma stress indicators (haematocrit, glucose, lactate, creatine phosphokinase and corticosterone), instrumental meat quality (pH24, water holding capacity, colour, raw and cooked texture) and sensory meat quality (using a trained sensory panel) in rabbits. The effect of the position of the animals on a multifloor rolling cage stand during lairage was also assessed. Lairage time had a significant effect on blood stress indicators, but only a slight effect on meat quality traits. A lairage duration of 6–8 h is recommended.     

Halal and kosher slaughter methods and meat quality: A review

There are many slaughter procedures that religions and cultures use around the world. The two that are commercially relevant are the halal and kosher methods practiced by Muslims and Jews respectively. The global trade in red meat and poultry produced using these two methods is substantial, thus the importance of the quality of the meat produced using the methods. Halal and kosher slaughter per se should not affect meat quality more than their industrial equivalents, however, some of their associated pre- and post-slaughter processes do. For instance, the slow decline in blood pressure following a halal pre-slaughter head-only stun and neck cut causes blood splash (ecchymosis) in a range of muscles and organs of slaughtered livestock. Other quality concerns include bruising, hemorrhages, skin discoloration and broken bones particularly in poultry. In addition to these conventional quality issues, the “spiritual quality” of the meat can also be affected when the halal and kosher religious requirements are not fully met during the slaughter process. The nature, causes, importance and mitigations of these and other quality issues related to halal and kosher slaughtering and meat production using these methods are the subjects of this review.     

Effects of two transport systems on lamb welfare and meat quality

The aim of this study was to analyse the effect of a direct transport system (DTS) versus transport with a logistic stopover system (TLS) on lamb welfare and meat quality at two seasons. A total of 96 lambs were sampled in a 2×2×2 factorial design, testing two transport systems and two seasons (summer and winter), with two replicates in each season. Significant interactions (P≤0.05) between transport system and season in both welfare and meat quality were found. In general, lambs subjected to direct transport and logistic stopover during winter had a more intense stress response and poorer meat quality than lambs transported during summer. However, direct transport during the cold season seemed to be the most stressful, compared to the rest of the groups, which was reflected in significantly higher levels of cortisol, lactate, glucose, ratio of N/L, higher pH24 and darker and tougher meat.