Air movement and the thermal microclimates observed in poultry lairages

1. The thermal environment experienced by broilers during transport and a 4 h lairage period were recorded for 8 loads of birds to 2 processing plants under summer and winter conditions. 2. During the transport period the thermal environment was considered not to have been a significant challenge to bird welfare. 3. During the lairage period, over all 8 d, external ambient temperatures were in the range 4° to 15°C during the winter trials and 12° to 29°C during the summer. Temperatures amongst the crated birds for this period were in the range 16° to 29°C and 20° to 31°C during the winter and summer trials respectively. 4. Air velocity measurements at bird level indicated air movement was of small magnitude (typically < 0.1 m/s) and of variable direction, despite the large air movements around the modules with speeds of over 1 m/s. 5. The potentially stressful thermal environments observed during lairage were achieved rapidly (< 1 h) after unloading. It is considered, therefore, that the minimisation of holding time alone is not a suitable control strategy. 6. The use of water-misting sprays as a control strategy in one lairage was observed to lower the temperature throughout the lairage but raised the humidity, which might offset the temperature advantage to the birds' thermoregulatory ability. 7. More closely controlled environments for broiler lairage facilities are suggested, with further work to increase air movement at bird level.     

Comparison of the effects of different transport conditions and lairage times in a Mediterranean climate in South Africa on the meat quality of commercially crossbred Large white x Landrace pigs

Information on the effect of road transportation conditions and lairage times on the meat quality of pork under South African conditions is very sparse. In this investigation, the effects of 2 road conditions (rough road with frequent stops - A; smooth road, few stops - B) and 2 lairage holding periods (2 h and 24 h) on the physical meat quality attributes of commercially produced pigs during summer (ambient temperatures > 30 degrees C) in the Western Cape (South Africa) were investigated. Pig meat from pigs transported on a road that caused more stress (A), had lower pH 45 (measured 45 min post mortem) values after 2 h lairage than pigs transported over a smoother road. Pigs B had a lower muscle pH 24 (measured 24 h post mortem) than group A, indicating that they had more glycogen reserves available for post mortem glycolysis. Road conditions A were more stressful resulting in a higher incidence of PSE pork, as shown by the percentage drip loss and the L* values. When the lairage period was increased to 24 h prior to slaughter, pigs transported under road conditions A had time to replenish their energy reserves and the pH 45, drip loss and L* values were within an acceptable range. However, pigs transported under road conditions B had lower pH 45 and higher pH 24 values, indicating that the lairage period was too long and that energy reserves were depleted in order to adapt to the stressful conditions. Results from this investigation indicate that improvement of the transport/road conditions will result in better pork quality.     

Optimal lairage times and conditions for slaughter pigs: a review

Keeping pigs in lairage provides a buffer to supply the slaughter line and allows the pigs to recover from the stress of transport. It has implications for the pigs' welfare by influencing their behaviour and ease of handling. In terms of pork quality, optimal lairage times for most pigs in the UK are probably one to three hours. Shorter lairage times are associated with more pale, soft, exudative (PSE) meat and longer times are associated with more dark, firm, dry (DFD) meat, more skin blemishes caused by fighting, and a lower carcase yield. However, when pigs have not been previously stressed by handling procedures, resting them in lairage may have no beneficial effects on the pigs' welfare or meat quality. At very high environmental temperatures there is evidence that a holding period of less than one hour may help to reduce the number of PSE carcases. At temperatures above 10 degrees C showering the pigs with water is beneficial. Fasting times need to be controlled to minimise the potential loss of carcase yield while reducing the volume of gut contents to reduce the risk of carcase contamination. Lairages can act as reservoirs of infection by pathogenic bacteria and there is evidence that longer holding times increase the risk of cross-contamination.     

Influence of transport conditions and pre‐slaughter water shower spray during summer on protein characteristics and water distribution of broiler breast meat

This study investigated the effects of pre‐slaughter transport during summer and subsequent water shower spray on broiler meat quality and protein characteristics. Arbor Acres broiler chickens (n = 126, 42 days old, mixed sex, 2.5‐3 kg) were randomly categorized into three treatments: (i) control group without transport (C); (ii) 30 min transport (T); and (iii) 30 min transport followed by 10 min water shower spray and 20 min lairage (T/W). Each treatment consisted of six replicates with seven birds each. Ambient temperature was 32‐35°C during transportation. Results indicated that transport during high ambient temperature denatured myosin and sarcoplasmic proteins, led to decreased protein solubility and resulted in glycogen phosphorylase precipitated to the myofibrillar fraction. Furthermore, meat quality in the transport group showed a pale, soft and exudative (PSE)‐like syndrome. Water shower spray during lairage after transport reduced the degree of protein denaturation and lessened the deterioration of meat quality.     

Influence of crate height during slaughter transport on the welfare of male turkeys

1. Poultry are usually transported in crates which provide the birds with very limited space. Slaughter transport of male turkeys is often carried out using crates that are 40?cm or less in height where it is not possible for them to stand up. There is little information on how this physical restriction over many hours affects the birds.

2. The aim of the study was to compare the welfare of male turkeys transported in crates 40?cm and 55?cm in height. Observations on the birds’ behaviour during lairage, carcass damage and meat quality were carried out after four commercial slaughter transport journeys.

3. Birds in 40?cm crates panted more and lay down more than birds in 55?cm crates during lairage. A large percentage of the carcasses had some damage. Significantly more birds from the 55?cm crates had scratches on their backs than birds from the 40?cm crates. There was no significant difference in meat quality between birds transported in the two crate heights.

4. Both positive and negative effects of increased crate height were established and there is no evidence from this study that merely increasing crate height improves turkey welfare. Other solutions should therefore be sought in order to improve the welfare of birds during transport.     

宰前休息方式对猪福利、血液成分及肉质的影响

选取体质量约为100 kg、氟烷基因型为NN的长×大二元杂交猪60头,随机分为3组:不休息组,休息3 h组,休息3 h+玩具组,公母各半.根据评分标准分别记录休息过程中猪的精神状况.放血时收集血样,用于分析血浆中皮质醇、促肾上腺皮质激素(ACTH)浓度,乳酸脱氢酶、肌酸激酶活性,乳酸、血糖浓度;添加EDTA-K<,2>抗凝剂的血样用于血细胞分析.同时在放血时,测定血温.屠宰后.测定背最长肌24 h滴水损失;背最长肌(LM)、半膜肌(SM)45 min以及24 h的pH、色值、导电率.结果表明:①休息3 h+玩具组在3个时间段的精神评分要极显著高于休息3 h组,随着时间的延长猪都表现出趋于平静的趋势;②休息3 h+玩具组和休息组3 h组在皮质醇、促肾上腺皮质激素要显著低于不休组(P<0.05),相反乳酸脱氢酶、肌酸激酶要显著高于不休息组(P<0.05),而休息3h+玩具组与休息3 h组差别不显著(P<0.05);③3个休息处理组在肉质指标上没有出现显著差别(P<0.05);④休息3 h+玩具组、休息3 h组在红细胞数(RBC)、血红蛋白含量(HGB)均要显著低于不休息组(P<0.05);休息3h+玩具组在白细胞数(WBC)上显著高于不休组(P<0.05);休息3 h组的淋巴细胞绝对值(W-SCC)显著高于不休息组(P<0.05);而休息3 h+玩具组与休息3 h组在所有的免疫指标上都没有显著差异(P>0.05).根据上述的结果显示,宰前一定要让猪有一个休息的过程,这种措施能有效缓解猪的应激,并能恢复其免疫能力;在休息的过程中,添加部分福利玩具,至少对猪的精神状态有明显的好处.     

Time in lairage needed by pigs to recover from the stress of transport.

Two experiments were carried out in which a total of 602 pigs were slaughtered after being held in lairage for periods ranging from less than one hour to 21 hours. In the first experiment the pigs were handled under ideal conditions and slaughtered at the University of Bristol slaughterhouse; in the second the pigs were killed at a commercial plant. Blood samples collected at exsanguination were analysed for indices of stress. There were no consistent effects of time in lairage on the levels of lactate and creatine phosphokinase. Plasma cortisol and beta-endorphin levels were reduced by lairage for three hours or more in the first experiment and cortisol was reduced by lairage for two hours or more in the second; beta-endorphin was not measured in the second experiment. A period of rest in lairage allowed the pigs to recover from transport and the associated handling and the recovery appeared to be complete within two to three hours.     

Stress of transportation for broilers

Transporting birds for two to four hours over distances of up to 224 km (140 miles) induced hyperlipacidaemia and hypoglycaemia while the concentration of plasma cholesterol decreased and then increased significantly. These responses were the same in summer and winter. Body temperature was not affected by the experimental conditions. There was a consistent increase in plasma corticosterone which was greater in winter than in summer.     

Negative effects of stress immediately before slaughter on pork quality are aggravated by suboptimal transport and lairage conditions

The objectives of the present experiment were 1) to study the effects of transport conditions and lairage duration on stress level, muscle glycolytic potential, and pork quality; and 2) to investigate whether the negative effects of high stress immediately preslaughter are affected by preceding handling factors (transport and lairage). In a 2 x 2 x 2 factorial design, halothane-free pigs (n = 384) were assigned to either short (50 min) and smooth or long (3 h) and rough transport; long (3 h) or short (<45 min) lairage; and minimal or high preslaughter stress. Pigs were processed in eight groups (48 pigs per group) on various days at a commercial plant. Blood samples were taken at exsanguination to measure plasma cortisol and lactate concentrations. Muscle pH and temperature were measured at 30 and 40 min, respectively, and both were measured at 3 h, postmortem. A LM sample was taken 135 min postmortem to estimate glycogen content and rate of glycolysis. Pork quality attributes were assessed 23 h postmortem. Short transport increased cortisol when followed by short lairage (transport x lairage; P < 0.01). Long transport, but not lairage (P > 0.30), tended to increase (P = 0.06) muscle glycolytic potential. Long transport tended to increase (P = 0.08) electrical conductivity, and decreased a* (P < 0.01) and b* (P < 0.02) values. Decreasing lairage from 3 h to <45 min decreased (P < 0.05) the L* value, but it did not (P > 0.10) affect other pork quality traits. High stress decreased (P < 0.001) muscle glycolytic potential, and increased (P < 0.001) plasma lactate, cortisol, muscle temperature, rate of pH decline, and ultimate pH. Except for decreased (P < 0.001) b* values, pork color was not (P > 0.40) affected by high stress, but water-holding properties (measured by electrical conductivity, filter paper moisture, and drip loss) were impaired (P < 0.001) by high stress. Fiber optic-measured light scattering and Warner-Bratzler shear force were not (P > 0.12) affected by any treatment. Comparisons with the "optimal" handling (short transport, long lairage, and minimal stress) revealed that, with regard to water-holding properties, the negative effects of high stress were aggravated by suboptimal transport and lairage conditions. High stress alone increased electrical conductivity by 56%, whereas high stress in combination with short lairage led to an 88% increase. However, high preslaughter stress contributed most and was the major factor responsible for reductions in pork quality.     

Behavioural and physiological responses of pigs to being transported for up to 24 hours followed by six hours recovery in lairage

Ninety-six pure-bred Large White pigs weighing 80 to 100 kg were either not transported or transported for eight, 16 or 24 hours, and then either slaughtered immediately on arrival at the abattoir or kept in lairage for six hours before being slaughtered. The pigs travelling for eight, 16 or 24 hours lost 2.2, 2.0 and 4.3 per cent of liveweight, respectively, and the pigs travelling for 24 hours lost 2.6 per cent of hot carcase weight Both liveweight and hot carcase weight recovered during the lairage period although there was a net liveweight loss in comparison with the control animals. Only transport for 24 hours led to losses in carcase weight The concentration of non-esterified fatty acids increased with the time spent travelling. The concentrations of cortisol, creatine phosphokinase and lactate were all low in comparison with the levels found in commercially slaughtered animals. Plasma albumin and protein concentrations indicated that the animals were becoming dehydrated during the longer journeys. The animals lay down for most of the journey and appeared to be asleep. During the period in lairage, the animals transported for eight hours had two distinct periods of feeding and drinking but spent most of the time lying down, but those transported for 16 and 24 hours showed far more eating and drinking activity. All the groups appeared tired, but the urge to eat of the groups transported for 16 hours, and especially 24 hours appeared to be more important. There were behavioural and the physiological differences between the transported groups and the controls. Six hours in lairage with access to food and water allowed most of the physiological parameters to return to pretransport levels.     

Effect of dietary methionine on performance, carcase characteristics and breast meat composition of heterozygous naked neck (Na/na+) birds under spring and summer conditions

1. Heterozygous naked neck (Na/na+) birds and their normally feathered counterparts (na+/na+) were fed from 0 to 7 weeks on 3 diets differing in methionine concentrations. From 0 to 3 and 3 to 7 weeks, respectively, the concentrations were: low containing 4.3 and 3.3 g/kg; optimum containing 5.0 and 3.8 g/kg and; high with 5.7 and 4.4 g/kg under spring (optimum ambient temperature) and summer conditions (high ambient temperature). Performance, carcase characteristics and breast meat chemical composition were determined. 2. Summer rearing resulted in a decrease in body weight, body weight gain, food consumption, and yields of carcase and breast. The summer temperature effect was more pronounced in males. Under summer temperatures, the protein content of the breast decreased while the fat content increased compared to birds reared in spring. 3. By 7 weeks of age, both genotypes reached similar body weights in the spring experiment while, in summer Na/na+ birds were 3.3% heavier and gained more in the period from 3 to 7 weeks than na+/na+ birds. Carcase and breast yields of Na/na+ birds were greater than in na+/na+ birds. 3. Second order polynomial coefficients of the dietary methionine effect were found to be significant for body weight at 3 and 7 weeks. Daily body weight gain between 3 and 7 weeks was linearly affected by the dietary methionine concentration. There was no interaction between genotype and methionine. 4. Methionine had no significant effect on carcase yield. Second order polynomial coefficients of the dietary methionine effect were found to be significant for breast yield while the methionine effect on abdominal fat was linear. Na/na+ females fed on the low methionine diet had lower protein content than the Na/na+ males. 5. It is concluded that the methionine requirement of Na/na+ birds did not differ from that of their normally feathered counterparts under either spring or summer ambient temperature conditions.     

Effects of journey and lairage time on steers transported to slaughter in Chile

Steers representative of the most common type, weight and conformation slaughtered in Chile were transported for either three or 16 hours and held in lairage for three, six, 12 or 24 hours. Measurements of liveweight, carcase weight, and the postmortem pH and colour of muscle were made to assess the economic and welfare effects of the different transport and lairage times. Compared with the short journey, the longer journey was associated with a mean (se) reduction in liveweight of 8.5 (2.8) kg, and there was a further decrease of 0.42 (0.18) kg for every hour that the animals were kept in lairage after 16 hours of transport, an increase in final muscle pH, a decrease in muscle luminosity and an increase in the proportion of carcases downgraded because they were classified as 'dark cutting The carcase weights also tended to be lower after the longer journey and after longer periods in lairage.     

Transport and lairage times of lambs slaughtered commercially in the south of England

The times spent in transport and lairage by 124,036 lambs slaughtered in two plants in the south of England were recorded. About half of them travelled for up to 120 km, taking up to four hours, and three-quarters travelled not more than 300 km, the journeys taking up to about six hours. Bimodal frequency distributions of lairage time were apparent; overall one third of the lambs spent up to four hours in lairage but more than 40 per cent were kept for longer than 14 hours, while they were held overnight. Early season lambs tended to travel shorter distances to slaughter and spent less time in lairage than late season lambs. The average total times spent in transit and lairage were 22.3 hours and 13.3 hours at the two plants.     

Investigation of the effects of transport and lairage on hydration state and resting behaviour of calves for export.

Plasma sodium concentrations, packed cell volume, total plasma protein concentration and dermal skinfold thickness were used to assess the state of hydration of 113 transported calves before and after lairage and in 30 control calves on the farm of origin. Skin thickness increased significantly (P less than 0.05) and total protein increased slightly during transport and decreased during lairage. These changes suggest that transport may cause dehydration and lairage may help in recovery. Plasma potassium concentration decreased during transport, but the effect was inversely related to the distance travelled, and the concentration increased during lairage. These changes are consistent with recovery from initially high cortisol levels at loading. The resting behaviour of 150 transported calves was recorded hourly for six hours. More time was spent resting and sleeping by the transported calves than has been reported for non-transported calves and more still by small transported calves, suggesting that transport is exhausting, that lairage helps recovery and that small calves are more adversely affected. During lairage the numbers of calves asleep decreased to values reported for normal calves, suggesting that 10 hours lairage was adequate. However, small calves did not return to their normal rest patterns within the observation period.     

Variations in chicken breast meat quality: implications of struggle and muscle glycogen content at death

1. Pectoralis major (P. major) muscle pH and meat quality traits were studied in relation to bird response to ante-mortem stress in three chicken lines: a fast-growing standard line (FGL), a slow-growing French 'Label Rouge' line (SGL) and a heavy line (HL). Ninety-nine birds of the three genetic types were slaughtered at their usual marketing age (6, 12 and 6 weeks for FGL, SGL and HL birds, respectively) on the same day. The birds of each line were divided into three different ante-mortem treatment groups: minimum stress (shackling for 10 s) (C), shackling for 2 min (SH) and acute heat plus shackling stress (exposure to 35 degrees C for 3.5 h and shackling for 2 min before stunning) (H + SH). 2. Regardless of chicken line, wing flapping duration (WFD) between hanging and stunning was strongly negatively related to P. major muscle pH at 15 min post-mortem. It was also moderately negatively related to P. major muscle glycolytic potential (GP), which represents glycogen level at death. Increasing WFD induced an increased ultimate pH (pHu) only in HL. The consequences of increased WFD for breast meat traits were dependent on the chicken line: it induced lower L* and b* and higher a* and drip loss in SGL while it only increased breast a* in HL birds. By contrast, WFD variations did not alter breast meat quality traits of FGL birds. Regardless of the chicken line, increased GP was associated with lower pHu and higher L* and drip loss. In SGL, it also increased b* and decreased curing-cooking yield of breast meat. 3. Struggling activity on the shackle line and muscle glycogen content at death could partly explain line and pre-slaughter variations in breast meat pH and quality traits. The water holding capacity of the raw and cooked meat was impaired by long shackling in the case of SGL birds while it was barely affected by ante-mortem conditions in the two standard lines. In conditions which minimised bird struggling (C), SGL and FGL birds had meat with a better water holding ability than that of broilers from the heavy line. However, when broilers were subjected to SH or H + SH conditions, the breast meat water holding capacity of SGL birds was lowered to the same level as that of the heavy line birds.     

Impact of commercial pre-harvest processes on the prevalence of Salmonella enterica in cull sows

This study examined the impact of transport and lairage on Salmonella enterica prevalence in cull sows held under commercial conditions. Five sampling periods over 10 weeks yielded 181 selected culls. Fecal sample positives at the farm and collection point were 2% and 3%, respectively. After transport and lairage 41% of cull sows yielded S. enterica in one or more sampled tissues. A significant increase in cecal isolations was observed. The two S. enterica serotypes found at the production site and collection point were found at the abattoir, as were 13 other serotypes. Transport and lairage practices may contribute to an increased S. enterica contamination immediately prior to slaughter.     

Effects of transport and lairage time on some blood constituents of Friesian-cross steers in Chile

The objective of this study was to determine the effect of two transport journeys (3 and 16 h) and four lairage times at the abattoir (3, 6, 12 and 24 h) on some stress indicators in steers to validate the current Chilean legislation of a minimum lairage period of 12 h for cattle arriving at abattoirs.The study was carried out twice, 80 steers in the winter and 80 in the summer of 1999. Forty steers were transported for 3 h and 40 for 16 h. At arrival in the slaughterhouse, the 40 transported steers were randomly divided in four lairage groups. Blood samples were collected before loading at arrival at the slaughterhouse and at slaughter during exsanguination.Mixed models were used to determine the associations between the stress indicators and the independent variables while correcting for the repeated observations on animals. Lairage increased plasma cortisol and PCV values independent of the transport duration. Glucose concentrations in steers transported for 16 h further increased after 3 and 6 h of lairage but decreased after 12 and 24 h of lairage. In steers transported for 3 h, glucose concentrations only increased after 24 h of lairage. After 24 h of lairage, the steers transported for 16 h had increased βHB concentrations compared with those transported for 3 h. Plasma CK activity was increased in steers after transport but was not affected by lairage. The study shows that there is no beneficial effect on the welfare of the animals by a long lairage time at the abattoir.     

Relationship between food deprivation before transport and aggression in pigs held in lairage before slaughter

Pigs from three farms were deprived of food for up to one hour, 12 hours or 18 hours before being sent for slaughter. In lairage, the animals' behaviour was monitored, and at slaughter a blood sample was collected and analysed for cortisol, lactate and creatine phosphokinase, potential indicators of stress and physical activity. The carcases were assessed for skin damage as an index of fighting, and rigor in the hind leg as an indicator of stress and/or fatigue. Measurements were also made of cold carcase weight, backfat thickness and liver glycogen concentration. General activity was very high on entry to the lairage pen. Drinking and mounting occurred almost immediately. Fighting developed after an exploratory period, and could last up to 60 minutes. There were large differences in the behaviour of pigs from the three farms. Pigs from farm A fought frequently but showed little mounting activity, whereas pigs from farm C were involved in mounting but little fighting. The period of food deprivation had no effect on average skin damage or rigor score, but the frequency of carcases with the highest scores was different The pigs deprived of food for up to an hour had the lowest incidence of severe skin damage and high rigor scores. Boars had a higher incidence of severe skin damage but a lower incidence of carcases with a high rigor score than gilts. Liver glycogen was almost completely depleted in the pigs deprived of food for 12 and 18 hours and was lower in the pigs deprived for up to an hour than in animals fed immediately before slaughter. The period of food deprivation had no effect on the levels of cortisol, creatine phosphokinase or lactate in the blood.     

Effects of maternal nutrition on the availability of energy in the body reserves of fetuses at term and in colostrum from Scottish Blackface ewes with twin lambs

Ewes carrying twin fetuses were maintained during late pregnancy on a uniformly high plane (n = 22), a uniformly low plane (LP) (n = 24) or a low plane increasing to a high plane (n = 14) of nutrition. Seven ewes at each nutritional level were killed at 142 days of gestation and the liver and muscle glycogen and body lipid concentrations of the fetuses were determined. The rest of the ewes lambed naturally at about 145 days and the colostrum yields were obtained by hand milking after oxytocin injections during the first 18 hours after birth. The lactose, lipid and protein concentrations of colostrum were determined. Undernutrition in the LP group did not apparently affect the body concentrations of available glycogen, reduced available body lipid by about 47 per cent and reduced the lactose, lipid and protein available in colostrum during the first 18 hours by about 50 per cent. Refeeding previously underfed ewes to a high plane during the last five to 10 days of pregnancy did not improve the available reserves of glycogen or lipid in the lambs but did increase the yields of colostral constituents by about 30 per cent. The relative contributions of body reserves and colostral constituents to the maintenance of high, medium and low metabolic rates in lambs from different groups was assessed. It was concluded that under normal field conditions refeeding undernourished ewes during the last weeks of pregnancy would improve only marginally the survival potential of the lambs and that most lambs would be compelled to draw on their body glycogen reserves in order to maintain heat production during the first 18 hours after birth, even when they consumed all the available colostrum.     

Physiological and behavioral responses of goats to 12-hour road transportation,lairage and grazing periods,and the modulatory role of ascorbic acid

Changes in physiological and behavioral responses of goats to road transportation have been demonstrated, but effects of lairage and grazing on transported goats and the role of ascorbic acid (AA) on the effects have not been elucidated. The aims of the experiment were to investigate physiological, behavioral, lairage and grazing responses of goats transported by road and administered with AA. Experimental goats (n = 20) were administered with AA, whereas control goats (n = 20) were given sterile water before transportation by road for 12 hours. The goats were either grazed or held in lairage after the transportation. Excitability scores, grazing time, liveweight, and activities of serum enzymes were evaluated in goats that were grazed and those kept in lairage. The results obtained post-transportation showed that 12 hours of road transportation and lairage was stressful to the goats, and it decreased (P < 0.05) their excitability scores, grazing time, and liveweight. The activities of alanine aminotransferase, aspartate aminotransferase, and creatine phosphate kinase rose after the transportation, especially in the control goats, kept in lairage. Overall, the results showed that extensively raised goats, transported for 12 hours during the hot-dry season, require a lairage period of 7-11 days for their metabolism, behavior, and liveweights to return to baseline values. Goats that were allowed to graze after transportation required 3 days to return to baseline values, but those administered with AA before transportation and grazed after transportation required only 2 days to recover. The results demonstrated that keeping goats in the lairage after transportation was not beneficial. In conclusion, AA administration ameliorated stress because of transportation by road, and post-transportation grazing facilitated the recovery of the goats from the stress.