The resting behaviour of 64 groups of sheep was observed in the lairages of two slaughterhouses after transport for about four hours in a commercial livestock transporter. The sheep were scanned at five minute intervals for the initial three hours in the lairage pen. The median percentage of time spent lying per group was 17 per cent (range 1 to 63). The percentage of time spent lying was not significantly related to the duration of transport, time of arrival or slaughterhouse. There was a significant positive relationship between space allowance (range 0.22 to 0.98 m2 per sheep) and percentage of time spent lying per group (P < 0.001). Increased space allowance also tended to be associated with a decrease in the occurrence of all interactions between the sheep (P = 0.05). Groups penned with two unfamiliar groups tended to spend less time lying than those penned on their own or with one other group (P = 0.07). There was no significant difference in the total percentage of time spent lying by groups penned on slats and those penned on straw. The results indicated that the ability of sheep to rest in the lairage may be compromised by providing low space allowances.

A total of 107 ear samples from all the pigs that died during transport or lairage at two commercial abattoirs were collected during two months (February and July), in order to determine their halothane genotype (NN, Nn or nn). The frequencies of the three halothane genotypes among dead pigs were significantly different (P < 0.001), being 4.7%, 24.3% and 71.0% for NN, Nn and nn individuals, respectively. The frequencies of pre-slaughter deaths within each genotype were estimated to be 0.02%, 0.09% and 2.29% for NN, Nn and nn genotypes, respectively. According to these results, the removal of both nn and Nn genotypes would give rise to an eleven-fold reduction in the pre-slaughter mortality rate (from 0.22% to 0.02%). It is therefore suggested that, from an animal welfare point of view, the elimination of the halothane gene in existing breeding schemes would have a major beneficial impact.

New transport legislation and society demands may increase the need for a ‘fast’ method to assess animal welfare at the abattoir. The objective of this study was to identify valid and feasible parameters which could be easily assessed at slaughterline in pigs. Eight transports (4 ‘far’ and 4 ‘near’ the abattoir) were evaluated using a questionnaire which included both animal-based and environment-based parameters. A ‘welfare index’ (WI) (0 = worst to 1 = best) was estimated for each transport based on the questionnaire. Lean and fat content, skin lesions, pH and electrical conductivity (PQM) were measured in 120 or 60 pigs per transport. When pH > 6 the meat was considered dry, firm and dark (DFD) and when PQM > 9 μs meat was pale, soft and exudative (PSE). Odds ratio between welfare index and slaughterline recordings was estimated. Differences in WI between the different transports were smaller than expected (WI ranged from 0.4 to 0.6). However, a significant relationship between higher percentage of DFD meat and lower welfare index (odds ratio: 2.25) was found. These results suggest that parameters like DFD meat could be used at the abattoir to perform a ‘snapshot’ welfare evaluation.

The effects on stickling lambs of two stocking densities during transport (high stocking density: eight lambs per m2; low stocking density: four lambs per m2) and two periods of lairage before slaughter (1.5 h and 3 h) were studied. The behaviour of lambs transported for short-duration journeys at the two stocking densities was recorded. At slaughter, blood samples were obtained after a lairage period and some physiological parameters related to stress were analysed: lactate dehydrogenase (LDH), creatine kinase (CK), calcium (Ca2+), Cortisol, and packed cell volume (PCV). There was a significant effect of stocking density on lambs’ behaviour during transit. The number of lambs walking was greater at low than at high density (84 and 20 observations, respectively: P < 0.001) whilst the number standing was lower at low density (852 and 366 observations, respectively). There was a significant effect (P < 0.001) of stocking density on the plasma concentration of LDH. The length of the period of lairage significantly affected plasma concentrations of LDH (P < 0.001), CK (P < 0.05), Ca2+ (P < 0.001) and Cortisol (P < 0.05), as well as PCV (P < 0.01). The results show that stocking density affects the lambs’ behaviour during transport. After the longer lairage period, plasma Cortisol concentration is lower; meanwhile, the activity of LDH and CK is higher.

Appropriate space allowances for animals are yet to be specifically determined for lairage. Space allowances that may be suitable for animals in lairage are suggested, based on reviewed studies of animals in transport, lairage and on farm. The longer animals are in lairage the more space they require, in order to be able to get up and lie down and lie undisturbed by congeners. Little work has been done on air quality and air flow characteristics in lairages. The range of ventilation must be sufficient to control levels of toxic or irritant gases such as carbon dioxide and ammonia and to remove excess heat and humidity; the latter being particularly relevant for pig lairages in hot weather. Intensities of sound measured in lairages often exceed 85 dB and there is evidence to suggest that such levels can be stressful especially for pigs; and human shouting appears particularly aversive to animals. Cattle vocalise in response to painful stimuli and to convey information to conspecifics that may be related to fear and distress. There is limited evidence that sheep adapt to continuous sound, provided it is not too loud, but respond to intermittent sounds such as gates banging and human shouting. Vocal communication between sheep may be less important than that between cattle and pigs. Levels of vocalisation are potential indices of animal welfare. Animals' prior experiences and factors such as sex, group size and constitution, pen design, and climatic or environmental conditions affect their welfare and responses to conditions in lairage.

Annual statistics for transport and lairage mortality were used to investigate factors leading to pre-slaughter mortality in Danish pigs. A subset of material from 2002, amounting to 17.8 million pigs, was used for a more detailed study of the effect of producer, haulier, abattoir and transport distance (< 100, 100–200 and > 200 km) on transport mortality. Total mortality was reduced eight-fold during the period that the halothane gene was being removed from the pig population, from 0.12% in the early 1980s to 0.016% in 2002. Overall, transport mortality increased with higher temperature and lower relative humidity/wind speed but a combination of temperature and humidity that fell into the danger zone, as defined by the Livestock Weather Safety Index, almost doubled transport mortality from a level of about 0.016 to 0.031%. Multiple deaths on the same transport were also more frequent during the hotter months of the year. Transport mortality increased with increasing transport distance, especially during warmer weather. Producers, hauliers and abattoirs had widely varying transport mortality. Eighty-nine percent of producers, 11% of hauliers and 86% of farmer transports had no mortality at all. Producers and farmer transports supplying less than 1,000 pigs had a higher transport mortality than those supplying more pigs, whereas it was independent of supply for hauliers. There were many confounding factors in this work, as producers, hauliers and abattoirs are linked and trends over the years can be affected not only by changes in the genetic makeup of the pig population but also by improvements in handling. Nevertheless, the study shows that internal environment within the vehicle and transport pattern, including the time the vehicle is stationary, are important factors for mortality and that particular efforts should be made if weather forecasts predict dangerous combinations of temperature and humidity. It is suggested that efforts to further reduce transport mortality in Danish pigs should concentrate especially on these factors and include a routine follow-up of all multiple deaths to pinpoint specific factors leading to mortality.

Attention to the welfare of animals during slaughter transport and lairage at the abattoir is important not only to consumers, but also to the meat production industry. Inadequate transport conditions can result in higher animal mortalities and meat quality problems after slaughter of such animals. In the present study the development of mortality rates both during and after the transport of slaughter pigs, and the incidence of pathological findings, was investigated. It could be shown that the percentage of animals which died during transport and in lairage clearly decreased between 1999 and 2003. This improvement was due mainly to the reduction of animal losses in the summer season where the highest losses over the investigated years occurred. Considering the duration of the transport it could be shown that not only very long (8 h), but also short journeys (1 h) can affect the welfare of animals with increased mortalities and pathological findings during the veterinary inspection at the slaughterhouse, particularly in the summer season. The results presented indicate that the tightening of European animal welfare legislation concerning loading, transport, unloading and lairage of slaughter pigs improved mortality rates and the incidence of pathological findings. Another reason could be a reduction of the percentage of stress susceptible pigs in the porcine population. However, until now the regulations on animal welfare during pig slaughter transport focused only on long-term journeys; the results presented show that short journeys can also affect the welfare of the animals.

There is interest in the transportation of horses (Equus caballus) to slaughter and a need to assess the welfare implications of this practice. Forty-six loads of 7-35 horses transported for 0.33 to 3.10 h to a slaughter plant in Iceland were studied. Adults and foals were transported together and then placed in separate pens overnight in the lairage. This acted as a weaning procedure for the foals. Between one and eleven horses per load (59 adults and 129 foals) were observed during loading and at the slaughter plant, blood was sampled at slaughter and carcases were observed. No wounds were observed before transport, but 1.6% of horses had small, superficial bleeding wounds after transport. The respiration rate was greater after, compared to before, transport. Blood lactate concentration measured after lairage and slaughter was greater than normal in both adults and foals, 13% of adults and 20% of foals had a blood glucose concentration lower than normal, and 58% of adults and 25% of foals had a plasma total protein concentration greater than normal. Forty-four percent of adults and 17% of foals were bruised. There were no pre-existing conditions affecting the fitness of the horses for transportation. The effects of transport on the physiological responses and the severity of bruising were relatively minor. However, the results suggested that the handling, transport and lairage of the horses resulted in injury and signs of exertion or stress that were not compatible with optimal management practices. The mild dehydration in adults might have been associated with restricted access to drinking water during lairage of lactating mares. Controlled studies are required to identify the specific practices used in Iceland that result in injury and dehydration.

The effect of transportation and lairage on the faecal shedding and post-slaughter contamination of carcasses with Escherichia coli O157 and O26 in young calves (4–7-day-old) was assessed in a cohort study at a regional calf-processing plant in the North Island of New Zealand, following 60 calves as cohorts from six dairy farms to slaughter. Multiple samples from each animal at pre-slaughter (recto-anal mucosal swab) and carcass at post-slaughter (sponge swab) were collected and screened using real-time PCR and culture isolation methods for the presence of E. coli O157 and O26 (Shiga toxin-producing E. coli (STEC) and non-STEC). Genotype analysis of E. coli O157 and O26 isolates provided little evidence of faecal–oral transmission of infection between calves during transportation and lairage. Increased cross-contamination of hides and carcasses with E. coli O157 and O26 between co-transported calves was confirmed at pre-hide removal and post-evisceration stages but not at pre-boning (at the end of dressing prior to chilling), indicating that good hygiene practices and application of an approved intervention effectively controlled carcass contamination. This study was the first of its kind to assess the impact of transportation and lairage on the faecal carriage and post-harvest contamination of carcasses with E. coli O157 and O26 in very young calves.

Pre-slaughter stress has a negative impact on animal welfare and on meat quality. Aggressive behaviour when pigs are mixed together for transportation to, or on arrival at, the abattoir is an important factor in pre-slaughter stress. Aggressiveness of pigs varies between individuals in the population, and this study investigated its effects on stress and meat quality at slaughter. We mixed pigs at a young age to identify individuals of high (H) or low (L) aggressive temperament using the previously validated approach of lesion scoring. To contrast extremes of social stress single-sex groups of eight pigs were mixed according to their aggressiveness in HH, HL or LL combinations or left unmixed (U) prior to transport and slaughter (n = 271). Each treatment was replicated in at least two groups in each of four slaughter batches. Mixing per se had little effect, but mixed groups composed of aggressive pigs (HH) had more carcass skin lesions and higher levels of plasma cortisol at slaughter and had loin muscle samples with higher pH at 24 h, and lower redness (a*) and yellowness (b*) compared to the other treatments. Females had higher levels of plasma cortisol at slaughter, a more rapid decline in pH post-slaughter and greater lean content of meat. Lactate and creatine kinase (CK) levels and meat pH were affected by the interaction of sex and treatment. Genetic factors, dam and sire line composition, and halothane locus (ryanodine receptor 1, RYR1) genotype, also affected a number of production and meat quality parameters as expected. Additionally, ‘commercially normal’ levels of social stress were studied in four further slaughter batches with no manipulation of group composition (n = 313). In these pigs, the proportion of unfamiliar pigs and group size of lairage groups explained limited variation in lesion scores at slaughter, but earlier aggressiveness did not. High numbers of skin lesions on the carcass were associated with high levels of cortisol and lactate and low glucose at slaughter, but not with meat quality measures. When stress and meat quality measures were compared for all pigs, high lactate was associated with low early pH and high drip loss, while high cortisol and CK were associated with high pH at 24 h and changes in meat colour. In conclusion, mixing pigs of above average aggressiveness resulted in greater aggression and stress, and changes in meat quality parameters, consistent with the effects of pre-slaughter stress on muscle chemistry.

A total of 1580 pigs killed in three slaughter -plants were held in lairage for ≥ 1 h, 3 h or overnight before slaughter. Blood samples were collected at exsanguination and subsequent carcass and meat quality monitored. Longer lairage reduced stress levels based on the concentration of cortisol, lactate and creatine phosphokinase in the blood. It also reduced the prevalence of pale, soft, exudative (PSE) but increased the prevalence of dark, firm, dry (DFD) meat. Additionally, it produced progressively greater amounts of skin damage caused by fighting between unfamiliar pigs and an overnight lairage reduced carcass yield and backfat thickness. The overall conclusion ivas that a period of between 1 and 3 h rest in lairage was optimal. There was no evidence that leaner, potentially more stress-susceptible pigs reacted differently from fatter, potentially more stress-resistant animals with regard to the effects of lairage time.

Two experiments were made to study the effects of a mist or large-droplet water spray for different lengths of time, on pig behaviour in lairage prior to slaughter and on subsequent carcass Quality. Water spraying caused more pigs to stand, chew the pen walls and root around the pen floor compared with unsprayed controls, and they also tended to fight more. The sprayed pigs produced meat of superior quality in terms of m. longissimus dorsi rate of acidification and colour. It is suggested that these benefits were due to the effects of evaporative cooling and increased water intake.