Welfare and carcass and meat quality of pigs being transported for two hours using two vehicle types during two seasons of the year

Animal Welfare Assessment and Meat Quality through Assessment of Stress Biomarkers in Fattening Pigs with and without Visible Damage during Slaughter

The study aimed to investigate the physiological and meat quality differences between Non-Ambulatory, Non-Injured (NANI), and without apparent abnormalities (non-NANI) pigs in a commercial slaughterhouse setting, focusing on the impact of stress and health conditions on the overall well-being and meat quality of the animals. A total of 241 surgically castrated crossbred male pigs from Southern Brazil were analyzed, with 131 non-NANI pigs and 110 NANI pigs. Infrared orbital temperature, rectal temperature, hematological parameters, and meat quality measurements were collected. Statistical analysis included ANOVA tests and principal component analysis (PCA). NANI pigs exhibited significantly higher infrared orbital temperatures and rectal temperature (p < 0.01). Hematological analysis revealed higher levels of hemoglobin, hematocrit, and red blood cells in NANI pigs (p < 0.05). White blood cell count and lactate dehydrogenase were significantly elevated in NANI pigs (p < 0.01), indicating potential infections or inflammatory responses. Meat quality parameters showed that NANI pigs had lower pH values, higher luminosity, and increased drip loss (p < 0.01), reflecting poorer water retention and potential muscle glycogen depletion. The study highlights the physiological and meat quality differences between NANI and non-NANI pigs, emphasizing the impact of stress, health conditions, and handling procedures on the animals. Blood biomarkers proved valuable in assessing physiological stress, immune response, and potential health issues in pigs, correlating with meat quality abnormalities. Utilizing these biomarkers as predictive tools can enhance animal welfare practices and contribute to improving meat quality in the swine industry.

Seasonal Variations on Testicular Morphology, Boar Taint, and Meat Quality Traits in Traditional Outdoor Pig Farming

Traditional outdoor pig farming is renowned for its emphasis on animal welfare and the production of highly valued, quality meat. While seasonality is known to impact certain animals, particularly those raised outdoors, there is a lack of research on Bísaro boars, a native Portuguese breed. This research study was conducted on a total of 20 male entire Bísaro pigs, reared in outdoor pens from 4 to 13 months old, and subsequently slaughtered. The animals were divided into two groups: one slaughtered in winter (Wi, n = 9), and the other in summer (Su, n = 11). The objective was to evaluate testicular morphometry, boar taint compounds, and meat quality traits, including sensory analysis and fatty acid profile. Testicles from the Su group exhibited reduced volume, indicating diminished functionality during that season. While no significant differences were observed in the boar taint compound analysis, panelists could discern a more intense aroma and flavor of boar taint in the Su meat. Other meat quality traits showed no significant variations, but the fatty acid profile displayed higher values in the Wi group. This study reveals that Bísaro boars experience reproductive seasonality, leading to variations in boar taint compounds across the seasons. This information is crucial for farm planning.

Review: The role of heat shock proteins in chicken: Insights into stress adaptation and health

This review article aimed to provide readers with a comprehensive understanding of the function of heat shock proteins (HSPs) in chicken physiology, stress response, and overall poultry health. With the increasing challenges faced by the livestock industry, particularly the poultry sector, due to climate change-induced high ambient temperatures, heat stress (HS) has become a critical concern. HS disrupts the thermal balance in poultry, leading to detrimental effects on growth, immune function, and overall health. HSPs play a pivotal role in mitigating the impacts of HS in chickens. These molecular chaperones are involved in protein folding, unfolding, and assembly, and they are classified into several families based on their size, including small molecule HSPs, HSP40, HSP60, HSP70, HSP90, and HSP110. By maintaining cellular homeostasis and promoting stress tolerance, HSPs act as vital guardians in helping chickens cope with HS and its associated consequences. The review synthesized relevant literature to shed light on the importance of HSPs in stress adaptation, cellular homeostasis, and the maintenance of normal cell metabolism in chickens. The adverse effects of HS on chickens include oxidative stress and compromised immune systems, making them more susceptible to infections. So also, HS negatively affects production performance and meat quality in poultry. Understanding the functions of HSPs in chickens offers valuable insights into stress adaptation and health, and could potentially lead to the identification of HSP biomarkers, genetic selection for heat tolerance, investigations into the interplay between HSPs and immune function, and the development of nutritional interventions to enhance HSP activity. By exploring these potential research directions, the review aimed to contribute to the development of novel approaches to mitigate the negative effects of HS on poultry, ultimately improving productivity and animal welfare in a changing climate.

Effect of loading density and weather conditions on animal welfare and meat quality of slaughter pigs

There are several factors that affect the welfare and meat quality of pigs during pre-slaughter transport. Among various factors, the effects of weather conditions and loading density were studied. A total of 3,726 finishing pigs were allotted to one of nine groups arranged in a 3 × 3 factorial design according to the weather conditions (low temperature [LT], under 10°C; normal temperature [NT], 10°C-24°C; high temperature [HT], upper 24°C), and loading density (low density [LD], upper 0.43 m2/100 kg; normal density [ND], 0.37-0.43 m2/100 kg; high density [HD], under 0.37 m2/100 kg). Each treatment group follow as: LTLD, LTND, LTHD, NTLD, NTND, NTHD, HTLD, HTND, HTHD. In terms of carcass composition, pigs had the highest carcass weight and backfat thickness at LT. Comparing the HD transport to the ND transport, the meat quality indicated a lower pH and more drip loss. The incidence rate of pale, soft, exudative (PSE) pork was high in the order of the HD, LD, and the ND transport (20%, 9%, and 2%, respectively). The HT transport showed the lowest pH and greatest L* value under the given weather conditions. Pigs transported under the HTHD and LTLD conditions had the greatest rates of PSE pork (40% and 20%, respectively). Pigs exposed to HD transport had the shortest laying time and the highest overplap behavior. The LDLT transport pigs had a shorter laying time than the LDNT and LDHT transport pigs. In conclusion, too high or too low density transport is generally not excellent for meat quality or animal welfare, however it is preferable to transport at a slightly low density at high temperature and at a slightly high density at low temperature.

Transport of Pigs of Two Market Weights at Two Space Allowances: Effects on Behaviour, Blood Parameters, and Meat Quality under Summer and Winter Conditions

This study was carried out through two separate experiments aiming at evaluating the effects of two space allowances (0.54 and 0.62 m2/pig in summer and 0.44 m2/pig and 0.50 m2/pig in winter) on the behavioural and physiological response, and meat quality of pigs of two slaughter weights (120 kg and 140 kg). In summer, higher blood haematocrit levels were found at slaughter in heavier pigs transported at a smaller space allowance (p = 0.04). During lairage, pigs transported at a smaller space allowance started fighting later (p = 0.04). Fighting behaviour was greater in heavier pigs (p ≤ 0.05), whilst their drinking activity was lower (p < 0.05). This resulted in greater exsanguination blood CK levels (p < 0.01) and drier hams (p = 0.05) in heavier pigs. In winter, only lower space allowance influenced some meat quality traits (p < 0.05), but these effects were minor. The effects of space allowance during summer transports on within-truck ambient conditions, post-transport pigs' welfare, and meat quality are similar. Mixing heavier pigs may result in greater aggressiveness and more fatigue-related meat quality variation during summer. Overall, winter transport results may have been biased by the short journey and within-truck load distribution.

Carcass and meat quality traits and their relationships in Duroc × Landrace × Yorkshire barrows slaughtered at various seasons

To understand characteristics of carcass traits and meat quality in pig population, 22 indicators of carcass characteristics and meat quality traits were measured on 278 Duroc × Landrace × Yorkshire barrows that were slaughtered in different seasons (spring, summer, autumn and winter). The effects of body weight and season on carcass characteristics and meat quality were analyzed by GLM procedure, followed the Bonferroni multiple test. The phenotypic correlations among those traits were calculated by employing the CORR procedure. In addition, the linear regression equations were constructed by stepwise regression model in REG procedure. The results showed that pigs slaughtered in spring had the heaviest body weight among the four seasons (P < 0.05), pigs slaughtered in summer had the lowest backfat depth and shear force (P < 0.05), and pigs slaughtered in winter had the lowest drip loss (P < 0.05). The results showed more variation in backfat depth, drip loss, intramuscular fat content, and shear force, compared with other indicators across pigs. Body weight had a significant association with loin eye area, average backfat depth and L^⁎_{24 h} (P < 0.05). Furthermore, regression equations for drip loss, cooking loss, shear force, and intramuscular fat content were constructed using more accessible indicators. Collectively, this study provided an overall view of carcass and meat quality traits in a commercial pig population in China, and illustrated that season significantly affected carcass characteristics and meat quality traits independently of body weight.

Commercial straight-deck trailer vibration and microclimate conditions during market-weight pig transport during summer

The objective of this study was to collect and quantify three-axis acceleration data from six locations within commercial pig transport trailers during summer. Two trucks with straight-deck trailers transporting two loads per day were observed for 5 consecutive days (N = 20). Accelerometers were placed under the floor of each trailer’s top and bottom decks (DECs) in the center of three sections (SECs): fore, middle, and aft. Data from each trailer section were processed to calculate z- and x,y-axis root mean square (RMS) values and vibration dose values (VDVs) during loading, transport, and unloading. There were no DEC × SEC interactions or SEC main effects for z-axis RMS or VDV during any transportation stage (P &gt; 0.06). The bottom deck had a greater x,y-axis RMS than the top deck during all transportation stages (P &lt; 0.01). The bottom deck had a greater x,y-axis VDV than the top deck during loading and transport (P &lt; 0.03), but there was no difference (P = 0.52) during unloading. The bottom deck had a greater z-axis RMS and VDV than the top deck during loading and transport (P &lt; 0.01), but there were no differences during unloading (P &gt; 0.07). There were no SEC effects for x,y- and z-axis RMSs and VDVs during all transportation stages (P &gt; 0.06). Acceleration values were compared with exposure action values (EAV; injury possible) and exposure limit values (ELV; injury likely) vibrations thresholds. Over the 5 observation days during all transport stages, a greater percentage of compartments violated both RMS and VDV thresholds in the x,y orientation (average 90%) than in the z orientation (average 76%). Overall, these data indicate that bottom decks experience greater three-axis vibrations than top decks in straight-deck trailers and that pigs on bottom decks may experience greater discomfort during transportation that could contribute to fatigue or the non-ambulatory condition.

Mortality during Transport of Pigs Subjected to Long Journeys: A Study in a Large European Abattoir

To date, especially in Europe, few studies have analysed the implications of long journeys on pig welfare and economic losses, expressed in terms of transport mortality. This study retrospectively analysed data collected from slaughtering registers and travel journals in a large Italian abattoir. We focused on pig transports coming from abroad and arriving at the slaughter plant after long journeys (a total of 59,982 pigs over 370 journeys). We explored the relationship between mortality and the following variables: country of origin, journey duration, astronomical season, stocking density on the truck, number of stops, and prolonged stops during the journey (lasting more than 60 min, likely due to traffic jams or truck problems). Overall, the low mortality rate observed (0.09%) was in line with European estimates. The factors with a significant or tendential effect on mortality during transport were the astronomical season (p = 0.0472, with higher mortality in spring) and the presence of prolonged stops during the journey (p = 0.069, tendential effect). Journey duration, stocking density, country of origin, and the number of stops were not statistically significant. In conclusion, based on this case study, using transport mortality combined with data collected during the common routine activity by the Public Veterinary Services in slaughterhouses could be a simple screening method for identifying problematic journeys or transport conditions.

Effect of distance and daily periods on heat-stressed pigs and pre-slaughter losses in a semiarid region

Effective planning animal transport is essential to safeguard animal welfare and reduce production losses. Environmental conditions, specifically extreme temperatures in combination with ranges of relative humidity are highlighted as one of the main risk factors for production losses during transport (e.g., fatalities). The majority of research evaluating both welfare and production impacts of pig transport have been primarily undertaken in Europe and North America, which cover a relatively limited range of distinct climates (e.g., temperate, sub-arctic, etc.). As a result, research on pig transport in semi-arid conditions is lacking. In this study, we evaluated the effects of both distance (short, 30 km; and long, 170 km) and transport daily periods (morning, (05:00-11:00); afternoon (12:00-17:00); and night, (23:00-04:00)) on the preslaughter losses and heat stress of pigs in commercial transport in a semiarid region. Across 19 journeys of standard slaughter-weight pig loads (124.0 ± 2.8 kg), 684 focal animals (36 per journey) were evaluated. For each journey, the load's thermal profile (THI_adj and enthalpy) and physiological responses of individual pigs were recorded. On arrival at designated slaughterhouses, the percentage pig of non-ambulatory non-injured (NANI), non-ambulatory injured (NAI), death on arrival (DOA), and total losses were recorded. Short journeys in the afternoon were shown to be more detrimental to the thermal comfort of pigs, with higher rectal temperatures recorded. The highest percentage of total losses and DOA occurred in afternoon journeys, irrespective of distance, followed by the morning, with the lowest losses observed in pigs transported at night. Additionally, total losses and DOA were further exacerbated by journey distance, with higher rates observed in short journeys. Higher percentage averages of NANI and NAI were observed in shorter journeys, but daily periods effects were only observed for NANI. These results further demonstrate the welfare and production loss risks associated with journey distance and time of day (representing varying environmental conditions) during road transport of pigs, whilst providing novel data in semiarid conditions. Careful and effective planning for pig transportation is essential to minimize heat stress and production losses. Consideration of the thermal environment on the day of travel, as well as providing flexibility to adjust travel times (e.g., early morning or evening), should help to mitigate risks of heat stress and production losses during pig transport.

Use of two novel trailer types for transportation of pigs to slaughter. 1. Effects on trailer microclimate, pig behaviour, physiological response, and meat quality under Canadian summer conditions

A total of 3,366 pigs were transported to slaughter in summer (six replicates/trailer type; July-August in southwestern Ontario) using three trailers: a modified triple-deck pot-belly (MPB), an advanced flat-deck (AFD), and a standard pot-belly (SPB). Within trailers, ambient conditions, temperature (T°C ), relative humidity (RH%), and temperature-humidity-index (THI), were monitored in three compartments (bottom front, BF, middle deck, MM, and top rear, TR). A total of 324 pigs were selected for the analysis of hematocrit, lactate, and creatine kinase (CK) levels in exsanguination blood and for the evaluation of pork quality as assessed in the longissimus (LM), semimembranosus (SM), and adductor (AD) muscles. The AFD and MPB trailers presented lower (P < 0.01) T°C and THI compared to the SPB during transit. In the SPB trailer, pigs transported in the MM compartment showed higher (P < 0.01) blood CK concentrations than those transported in the BF compartment and lower pHu values in the SM and AD muscles (P = 0.02 and P = 0.04, respectively) than those transported in the TR compartment. Although the AFD trailer design provided a better microclimate for pigs, the improvements in the design of the novel trailers only slightly reduced stress in pigs during summer transits.

Use of two novel trailer types for transportation of pigs to slaughter. 2. Effects on trailer microclimate, pig behaviour, physiological response, and meat quality under Canadian winter conditions

In total, 3,654 market pigs were transported to slaughter in winter (six replicates/treatment; January-February in southwestern Ontario) using three trailers: a modified triple-deck pot-belly (MPB), an advanced flat-deck (AFD) trailer, and a standard pot-belly (SPB). Within trailers, ambient conditions, temperature (T°C), relative humidity (RH%) and temperature and humidity index (THI), were monitored in three compartments (bottom front, BF, middle middle deck, MM, and top rear, TR). In total, 324 pigs were selected for the analysis of hematocrit, lactate, and creatine kinase (CK) levels in exsanguination blood and for the evaluation of pork quality as assessed in the longissimus (LM), semimembranosus (SM), and adductor (AD) muscles. The SPB trailer overall was approximately 2.5°C warmer (P = 0.01) compared to the MPB and AFD trailers while stationary at the farm. No differences (P > 0.10) in blood variables were found between trailers. The pHu value of the SM muscle was greater (P = 0.05) for pigs transported in the SPB trailer than in the AFD and MPB trailers. Given the few substantial effects of trailer models on animal welfare and meat quality, these three trailer models can be used indifferently for short-distance transportation in winter conditions in Canada.

Effect of heat stress on growth and production performance of livestock and poultry: Mechanism to prevention

Heat stress is a widespread phenomenon in domestic animal feeding in tropical and sub-tropical areas that are subjected to a growing negative effect in livestock and poultry due to global warming. It leads to reduced food intake, retarded growth, intestinal disequilibrium, lower reproductive performance, immunity and endocrine disorders in livestock and poultry. Many studies show that the pathogenesis of heat stress is mainly related to oxidative stress, hormone secretion disorder, cytokine imbalance, cell apoptosis, cell autophagy, and abnormal cell function. Its mechanism refers to activation of mitogen-activated protein kinase (MAPK) signaling pathway and nuclear factor kappa B (NF-κB) signaling pathway, the fluctuation of tight junction protein and heat shock protein expression, and protein epigenetic modification. This manuscript reviews the mechanism of heat stress through an insight into the digestive, reproductive, immune, and endocrine system. Lastly, the progress in prevention and control techniques of heat stress has been summarized.

Behavior, blood stress indicators, skin lesions, and meat quality in pigs transported to slaughter at different loading densities

A total of 1,936 pigs were transported through 8 trips (8.4 ± 0.5 hr) from 2 grow-to-finish farms to a commercial slaughter plant, all located in Southern Brazil. On each trip, a sub-sample of each load (36 barrows/load, weighing 118.9 ± 9.8 kg) was randomly allocated into one of the following loading densities during transport: 200 kg/m2 (D200), 235 kg/m2 (D235), and 270 kg/m2 (D270). Behavioral recordings of postures and activities were made during transportation and lairage using video-cameras. At slaughter, blood samples were collected to assess the concentrations of creatine kinase (CK) and lactate. Carcass weights and skin lesion scores were assessed on-line, and meat quality was evaluated in the longissimus thoracis (LT) muscle by assessing pH, color, and drip loss. During transportation, the proportion of animals lying down was higher (P < 0.05) in D200 and D235 groups compared with D270. The proportion of sitting animals during transportation was higher (P < 0.01) in D270 compared with D200. In lairage, D200 and D235 pigs stood more compared with D270 (P = 0.01), while the proportion of lying pigs was higher (P = 0.02) for D270 pigs compared with D200 and D235. The frequency of drinking bouts in lairage was higher (P < 0.05) for D200 group compared with D235 and D270. The levels of CK were lower (P < 0.05) in D200 pigs transported compared with D270. Lesion scores tended to be higher (P = 0.06) in D270 carcasses compared with D200 and D235. A tendency for lower (P = 0.10) pH1 values in the LT muscle of D270 pigs compared with D200 pigs was also found. Based on the results of this study, the application of lower loading densities (≤235 kg/m2) in the truck allows pigs to have sufficient space to rest, travel more comfortably and arrive less fatigued at the slaughter plant.

Identification of trailer heat zones and associated heat stress in weaner pigs transported by road in tropical climates

Heat stress is major welfare concern during transport of pigs in tropical climates, which can also lead to direct production costs. This study evaluated the dynamics of heat zones through the load and their relationship with heat stress of weaner pigs during road transport in a tropical climate. Both environmental (e.g. temperature and relative humidity) and physiological (e.g. respiratory frequency and lactate) measures were recorded from four vehicle journeys (70 km distance, 216 weaner pigs within each trailer load) within Ceará, northeastern Brazil. Geostatistics and fluid dynamics simulation techniques were applied to understand the dynamics of heat zones and ventilation patterns the truckload. Statistics based on canonical discriminant analysis and ANOVA were performed to verify the relationship between heat zones and heat stress in pigs. The results showed that, during transport, the generation of heat zones occurred with different magnitudes along the load (P < 0.05), which was harmonized by the ventilation dynamics. There was a heat core with high energy content, in the front region of the lower deck (LD) of the trailer. In this zone, weaners pigs had higher rectal temperature (+1.8 °C temperature difference), respiratory frequency (LD = 94 ± 1.3 breaths/min; UD = 86 ± 1.3 breaths/min), and blood cortisol concentration (LD = 32.9 ± 0.8 ng/mL; UD = 30.18 ± 0.6 ng/mL) (all P < 0.05). Weaners pigs transported in the upper deck (UD) compartments had the highest skin temperature (LD = 38.13 ± 0.3 °C; UD = 38.9 ± 0.22 °C) and the highest mean values of blood lactate (LD = 65.5 ± 1.11 m/M; UD = 71.60 ± 1.19 m/M) and Creatine kinase (LD = 3891.23 ± 69U/L; UD = 4107.43 ± 62U/L) (P < 0.05). Weaners transported in compartments of the LD of trailer were more susceptible to heat stress, while weaners in the UD compartments were more susceptible to physical stress and muscle exhaustion. These results provide additional evidence of heat zones within trailer compartments and highlight the requirement for the planning of pig transport operations in tropical climates to mitigate risks of heat stress.

The effects of season on health, welfare, and carcass and meat quality of slaughter pigs

This study assessed the effects of season on health, behaviour, physiological stress parameters, and carcass and meat quality in a total of 480 slaughter pigs. The following health indicators were recorded: pneumonia, pleurisy, milk spots, and pericarditis. Behaviour was monitored during unloading (slipping, falling, turning back, reluctance to move, panting, shivering) and lairaging (panting, shivering, huddling). Blood lactate and glucose concentrations were determined at exsanguination. Performance indices (live weight, daily weight gain), carcass (carcass weight, backfat and loin thickness, lean meat content, carcass lesion score), and meat quality (pH, temperature, drip, thawing and cooking losses, colour, marbling) traits were measured postmortem. Pigs slaughtered in winter had the highest live weight, carcass weight, loin thickness, and carcass lesion score, while the lowest live weight, carcass weight, and backfat thickness were recorded in pigs slaughtered in summer. The highest lactate and glucose concentrations were recorded in pigs slaughtered in summer. The highest prevalence of red, soft, and exudative meat was recorded in pigs slaughtered in winter. Pigs slaughtered in summer had the lowest pH, the highest thawing loss, L* value, b* value, and occurrence of pale, soft, and exudative meat. Pigs slaughtered in autumn had the lowest drip loss, cooking loss, L* value, b* value, and the greatest percentage of red, firm, and nonexudative meat. In conclusion, the summer and winter temperatures compromised health and welfare and reduced carcass and meat quality in slaughter pigs, indicating that protection against heat and cold stress is not yet effective.

Welfare of pigs during killing for purposes other than slaughter

Pigs at different stages of the production cycle may have to be killed on-farm for purposes other than slaughter (where slaughter is defined as killing for human consumption) either individually (e.g. severely injured pigs) or on a large scale (e.g. unproductive animals or for disease control reasons). This opinion assessed the risks associated with the on-farm killing of pigs and included two phases: 1) handling and moving of pigs and 2) killing methods (including restraint). The killing methods were subdivided into four categories: electrical methods, mechanical methods, gas mixture methods and lethal injection. Four welfare consequences to which pigs can be exposed to during on-farm killing were identified: pain, fear, impeded movement and respiratory distress. Welfare consequences and relevant animal-based measures were described. In total, 28 hazards were associated with the welfare consequences; majority of the hazards (24) are related to Phase 2 (killing). The main hazards are associated with lack of staff skills and training, and poor-designed and constructed facilities. Staff was identified as an origin of all hazards, either due to lack of skills needed to perform appropriate killing or due to fatigue. Corrective measures were identified for 25 hazards. Outcome tables linking hazards, welfare consequences, animal-based measures, hazard origins, preventive and corrective measures were developed and mitigation measures proposed.

Welfare of pigs at slaughter

The killing of pigs for human consumption (slaughtering) can take place in a slaughterhouse or on farm. The processes of slaughtering that were assessed for welfare, from the arrival of pigs until their death, were grouped into three main phases: pre-stunning (including arrival, unloading from the truck, lairage, handling and moving of pigs); stunning (including restraint); and bleeding. Stunning methods were grouped into three categories: electrical, controlled atmosphere and mechanical. Twelve welfare consequences the pigs can be exposed to during slaughter were identified: heat stress, cold stress, fatigue, prolonged thirst, prolonged hunger, impeded movement, restriction of movements, resting problem, negative social behaviour, pain, fear and respiratory distress. Welfare consequences and relevant animal-based measures were described. In total, 30 welfare hazards that could occur during slaughter were identified and characterised, most of them related to stunning and bleeding. Staff were identified as the origin of 29 hazards, which were attributed to the lack of appropriate skill sets needed to perform tasks or to fatigue. Corrective and preventive measures for these hazards were assessed: measures to correct hazards were identified, and management was shown to have a crucial role in prevention. Outcome tables linking hazards, welfare consequences, animal-based measures, origins and preventive and corrective measures were developed for each process. Mitigation measures to minimise welfare consequences are proposed.

Application of extended feed withdrawal time preslaughter and its effects on animal welfare and carcass and meat quality of enriched-housed pigs

A total of 144 barrows were distributed into four treatment groups. One group was housed conventionally and fasted for 16 h preslaughter, while the other three groups were housed in enriched conditions (straw-bedding and low density) and fasted for 16, 24 and 32 h preslaughter. When compared with conventionally-housed pigs, enriched-housed pigs were heavier (P < .05) and fatter (P < .01), but easier to handle at loading (P < .05) and produced less exudative pork (P < .05) possibly resulting from a lower post-mortem muscle glycolytic potential (P = .10). Extending fasting time up to 32 h reduced dressing yield (P < .001) and increased skin lesion scores (P < .01), but did not result in any clear or major effect on muscle metabolism and meat quality. In conclusion, given the beneficial effects of enriched housing conditions on stress response and pork quality, the application of an extended fasting time (32h) preslaughter is not required for this production.

Effects of Housing, Short Distance Transport and Lairage on Meat Quality of Finisher Pigs

Simple Summary

Knowledge of stressful stimuli is a fundamental aspect to improve and evaluate animal welfare. Animal stressors vary in function of, for example, housing, climate and handling technique. That is why it is important to investigate animal welfare in different circumstances (e.g., type of housing, climate and region). Belgian pig production is based on the Piétrain breed which is associated with the halothane gene and hence with the genetic susceptibility to stress. In pigs, there is a negative correlation between stress in the last few hours of their life and the final meat quality. In our research we investigated several potential parameters that could influence the meat quality of pork. We can conclude that numerous parameters on farm, during transport and in slaughterhouse influence meat quality. Specifically, reducing lung lesions by vaccination during raising, no mixing of pigs during the transport process, sufficient lairage time and transporting no extreme muscled pigs can improve meat quality. Adequate control and application of guidelines on farm, transport and slaughterhouse level are necessary to improve animal welfare, but also to reduce deterioration of meat quality important for the financial aspect and the appreciation of the consumer.

Abstract

Transport and associated handling can have adverse effects on pig welfare and meat quality. The purpose of the study was to determine (the variation of) effects of farm management, climate parameters, transport and lairage conditions on the meat quality of fattening pigs, heterozygous for the halothane gene. A total of 4763 fattening pigs were transported from 1 farm to a commercial slaughterhouse (distance 110 km) in 121 transports. From 2404 carcasses, carcass temperature and pH were measured 45 min post-mortem; 48 hours post-mortem pH, electrical conductivity, drip loss and meat color were registered. During the raising period sex, conditions at weaning (purchased or not as piglet, vaccination against mycoplasma) and (type of) pen during fattening (i.e., from about 22 kg to 105 kg) were registered to relate with pork quality. Transport season, weather parameters, regrouping or not during loading, transport combination (truck, trailer and driver), transport compartment and transport conditions (loading density, transport duration and unloading time) were monitored. At the slaughterhouse, duration of lairage and carcass conformation were followed up to examine correlations with meat quality parameters. Effects of farm management, climate parameters during transport, transport and slaughterhouse conditions on pork quality were demonstrated. Specifically, reducing lung lesions by vaccination during raising, no mixing of pigs during the transport process, sufficient lairage time and transporting no extreme muscled pigs can improve meat quality.

Identifying Physiological Stress Biomarkers for Prediction of Pork Quality Variation

Simple Summary

Prediction of technological and sensory pork quality—during a pig’s life or quickly after slaughter—is increasingly required by the pork industry in order to classify carcasses or primary cuts of carcasses for different production lines. Therefore, there is increasing demand for the development of accurate, reliable, time-efficient, non-invasive, real-time tools for predicting pork and carcass quality characteristics. Based on this, the aim of this study was to assess the potential use of various physiological stress biomarkers as indicators of carcass and meat quality traits in slaughter pigs subjected to the standard marketing conditions and to minimal stressful preslaughter handling. According to the results of this investigation, lactate dehydrogenase can be considered as a useful predictor of pork quality, while cortisol, alanine amino transferase, and albumin could be useful in prediction of carcass quality.

Abstract

This study assessed the potential use of various physiological stress biomarkers as indicators of carcass and meat quality traits in 240 pigs subjected to the standard marketing conditions and minimal stressful antemortem handling using Pearson correlations. The most important pork quality traits (pH and temperature, water holding capacity, and color) had limited correlations with stress metabolites (lactate, glucose), stress hormones (cortisol, adrenocorticotropic hormone), stress enzymes (creatine kinase, aspartate amino transferase, alanine amino transferase), electrolytes (sodium, chloride), and acute-phase proteins (haptoglobin, C-reactive protein, albumin), indicating poor reliability in predicting pork quality. Albumin level was moderately positively correlated with live weight, hot carcass weight, cold carcass weight, and back fat thickness. Alanine amino transferase level was moderately positively correlated with live weight, hot carcass weight, and cold carcass weight. Cortisol level was moderately positively correlated with live weight, hot carcass weight, cold carcass weight, and back fat thickness, and moderately negatively correlated with the lean carcass content. Increased lactate dehydrogenase level was moderately correlated with decreased drip and cooking loss. In conclusion, lactate dehydrogenase could help pork producers predict pork quality variation, while cortisol, alanine amino transferase, and albumin could be useful in prediction of carcass quality.

Meat quality in the Danish pig population anno 2018

The level of meat quality was assessed in a random sample of the Danish pig population. No PSE was found in m. semimembranosus, and, depending on the definition of PSE, no pigs or only 2% of the pigs were categorised as having PSE in the M. longissimus lumborum. The ultimate pH had a low variability in M. longissimus lumborum (2.5%), m. semimembranosus (2.7%) and m. semispinalis capitis (4.9%) indicating that the quality of the meat with respect to these attributes was uniform. The drip loss was as high as 7%, although on average (2.23%) its value was lower than that previously found in a sample of the Danish pig population. A gender difference between entire male pigs and castrates was seen for drip loss and tenderness (shear force), with loins from castrates being less exudative (P < .001) and more tender (P < .01) than those from entire males. In conclusion, the Danish pig population showed a uniform meat quality.

Effects of dietary γ-aminobutyric acid supplementation on antioxidant status, blood hormones and meat quality in growing-finishing pigs undergoing transport stress

γ-Aminobutyric acid (GABA) is a natural nonprotein amino acid distributed in animals, plants and microbes. GABA is an inhibiting neurotransmitter which takes great effect in mammalian central nervous system. We carried out the research to study the influence of GABA on blood hormone concentrations, antioxidant status and meat quality in fattening pigs after transportation. The 72 pigs with a starting weight of approximately 32.67 ± 0.62 kg were randomly allocated to 2 groups based on dietary treatments, containing 6 replicates with 6 pigs in each. The pigs were fed dietary supplementation of GABA (0 or 30 mg/kg of diets) for 74 days. Twelve pigs were randomly selected from each group and assigned to the either 1 hr of transport (T group) or no transport (N group), resulting in two-factor factorial design. Compared to the control, GABA supplementation increased average daily gain (ADG) (p < .01) and decreased feed-gain ratio (F/G) (p < .05). The pH_45 min was lower and drip loss was greater in the longissimus muscles (LM) of post-slaughter of transported pigs (p < .05). The pH_45 min of 0/T group (group with 0 mg/kg GABA and transport) was significantly lower than the pH_45 min of the 30/T group (diet × transport; p < .05). GABA supplementation significantly increased serum glutathione peroxidase (GSH-Px) concentration (p < .05) before transportation. Following transport, pigs fed GABA had decreased concentrations of serum malonaldehyde (MDA), adrenal cortical hormone and cortisol (p < .05). The results indicate that feeding GABA significantly increased the growth performance of growing-finishing pigs. The transportation model negatively impacted meat quality, antioxidant indexes and hormone parameters, but dietary supplementation of GABA could suppress the rise of drip loss of LM, ACTH and COR and suppress the drop of pH_45 min of LM after transportation stress in growing-finishing pigs. Feeding GABA alleviated transportation stress in pigs.

A Review of Swine Transportation Research on Priority Welfare Issues: A Canadian Perspective

The purpose of this review is to present the best available scientific knowledge on key animal welfare issues during swine transport, such as transport duration and distance, time off feed and water, rest intervals, environmental conditions, loading density, and transport of young animals, based on their impact on stress, injury, fatigue, dehydration, body temperature, mortality, and carcass and meat quality. The review was limited to this set of priority welfare issues which were identified by the National Farm Animal Care Council (NFACC) Scientific Committee to help with the development of the livestock transportation Codes of Practice. This review focuses primarily on research related to the transport of market pigs (100–135 kg) which is a reflection of the current literature available on pig transportation. This information presented here can be used to support other animal welfare codes, guidelines, standards or legislations regulating the welfare of pigs during transport. Based on the available literature, clear conclusions can be drawn on the impact of vehicle design, pre-transport fasting, control of environmental conditions and loading density on the welfare of pigs during transport and on pork quality. However, the effects of journey duration are still unclear and a recommendation on the maximum transport time cannot be provided. Further studies investigating the impact of factors, such as ambient conditions within the transport vehicle, loading density at extreme ambient conditions, travel distances, maximum travel duration, rest/stop duration, and management of pigs during rest stops are required. More specifically, further research in relation to the welfare of market weight, newly weaned and breeding pigs, and cull sows and boars during transport is needed.

Effects of pre-slaughter short-term factors on pork quality

We examined the effects of pre-slaughter short-term factors including season of the year, duration of transportation and lairage time, as well as sex of pigs, on pork quality. Meat samples were collected from 590 pigs (females, entire and castrated males) that were slaughtered in a commercial abattoir in Greece over a 15-month period. Meat quality parameters pH, colour, drip loss, cooking loss, Warner–Bratzler shear values and sarcomere length were measured on the longissimus dorsi. DNA was isolated from blood samples and the frequency of the recessive halothane gene mutation HALn was determined. The results demonstrated that pork quality with respect to pH and L* values was normal in 93.9% of the samples, with 5.1% of samples classified as PSE (pale, soft and exudative) and 1.0% as DFD (dark, firm and dry). Duration of transportation was critical: brief and long transfers had the ability to impair meat quality. A lairage time of 2–4 h before slaughter was adequate when the pigs were free of HALn and the climatic conditions were not extreme. Season of the year was a very important factor, with significant variations recorded in meat-quality parameters between winter and summer months. Finally, the sex of the animals was responsible for differences in meat quality, but these differences were small and unlikely to be identified by the consumers.

Preslaughter handling practices and their effects on animal welfare and pork quality

At all times, prior to slaughter, pigs may experience stress from a range of handling practices, such as fasting, loading and transport, mixing, and interaction with humans. These factors can affect the welfare of pigs and carcass and meat quality, both individually and collectively. Preslaughter stress is both an animal welfare and a meat quality issue. Behavioral and physiological studies have revealed that poor handling practices at the farm, during transport and at the slaughter plant, have an adverse effect on pigs and may result in the loss of profits due to animal losses during transport and in lairage. Also, poor preslaughter handling can also lead to losses in carcass value as a result of reduced yield, the presence of lesions and bacterial contamination, and meat quality defects (e.g., pale, soft, exudative and dark, firm, dry pork). These economic losses can be limited by improving the design of facilities, controlling the environmental conditions, and implementing training programs for the correct animal handling at any stage preslaughter. The objective of this review was to review research findings on the effects of preslaughter practices on ante-mortem behavioral and physiological response in pigs, including muscle metabolism, and to provide recommendations aimed at limiting the impact of preslaughter handling on animal losses and pork quality.

Characterization of variability in pork carcass composition and primal quality,

The objective was to characterize the factors and production practices that contribute to variation in pork composition and quality. It is possible the variation in pork quality traits, such as color, marbling, and tenderness, contributes to reduced customer confidence in the predictability of finished product quality and, therefore, pork products becoming less competitive for consumer dollars. Pigs raised in 8 different barns representing 2 seasons (hot and cold) and 2 production focuses (lean and quality) were used in this study. Pigs were marketed in 3 groups from each barn and marketing procedures followed commercial marketing procedures. Data were collected on a total of 7,684 pigs. The mivque0 option of the VARCOMP procedure in SAS was used to evaluate the proportion of variation each independent variable (season, production focus, marketing group, sex, and random variation) contributed to total variance. Random variation including inherent biological differences, as well as factors not controlled in this study, contributed the greatest proportion to total variation for each carcass composition and quality trait. Pig and other factors contributed to 93.5% of the variation in HCW, and marketing group, sex, season, and production focus accounted for 4.1, 1.4, 0.8, and 0.3%, respectively. Variation in percent carcass lean was attributed to production focus (36.4%), sex (15.8%), and season (10.2%). Pig and other factors contributed the greatest percentage of total variation (39.4%). Loin weight variation was attributed to production focus (21.4%), sex (5.4%), season (2.7%), marketing group (1.8%), and pig (68.7%). Belly weight variation was attributed to pig (88.9%), sex (4.1%), marketing group (3.8%), production focus (3.0%), and season (0.1%). Variation in ham weight was attributed to pig and other factors (93.9%), marketing group (2.8%), production focus (2.2%), and season (1.1%). Ultimate pH variation was attributed to pig (88.5%), season (6.2%), production focus (2.4%), marketing group (2.2%), and sex (0.7%). Aside from pig (71.9%), production focus (14.0%) was the next largest contributor to variation in iodine value followed by sex (13.2%) and marketing group (0.9%). Variation in carcass quality and composition could be accounted for, but the greatest percentage of variation was due to factors not accounted for in normal marketing practices.

Review: Effects of Ractopamine Hydrochloride (Paylean) on welfare indicators for market weight pigs

This review summarizes the effects of ractopamine hydrochloride (RAC) dose (5, 7.5, 10, and 20 mg/kg) on market weight pig welfare indicators. Ractopamine hydrochloride (trade name Paylean) is a β-adrenergic agonist that was initially approved in the U.S. in 1999 at doses of 5 to 20 mg/kg to improve feed efficiency and carcass leanness. However, anecdotal reports suggested that RAC increased the rate of non-ambulatory (fatigued and injured) pigs at U.S. packing plants. This led to the addition of a caution statement to the Paylean label, and a series of research studies investigating the effects of RAC on pig welfare. Early research indicated that: (1) regardless of RAC administration, fatigued (non-ambulatory, non-injured) pigs are in a state of metabolic acidosis; (2) aggressive handling increases stress responsiveness at 20 mg/kg RAC, while 5 mg/kg reduces stress responsiveness to aggressive handling. Given this information, dosage range for Paylean was changed in 2006 to 5 to 10 mg/kg in market weight pigs. Subsequent research on RAC demonstrated that: (1) RAC has minimal effects on mortality, lameness, and home pen behavior; (2) RAC fed pigs demonstrated inconsistent prevalence and intensity of aggressive behaviors; (3) RAC fed pigs may be more difficult to handle at doses above 5 mg/kg; and (4) RAC fed pigs may have increased stress responsiveness and higher rates of non-ambulatory pigs when subjected to aggressive handling, especially when 20 mg/kg of RAC is fed.

Use of Temperature, Humidity, and Slaughter Condemnation Data to Predict Increases in Transport Losses in Three Classes of Swine and Resulting Foregone Revenue

The United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) conducts weekly surveillance of slaughter condemnation rates to provide early warning for emerging diseases and to monitor health trends in swine. Swine deaths in-transit are an animal welfare concern and represent lost revenue for the swine industry. This retrospective observational study used ambient temperature and humidity data from weather stations near United States slaughter plants collected from 2010 to 2015 to predict the incidence and risk of death among swine in-transit and just prior to slaughter. The risk of death for market swine at a heat index (HI), which combines the effects of temperature and humidity, indicating moderately hot weather conditions between 85 and 92°F was 1.37 times greater than that of the baseline temperature range of 54–79°F. The risk of death for cull sows at an HI between 85 and 92°F was 1.93 times greater than that of average temperatures ranging from 54 to 79°F. Roaster swine (weigh < 220 lbs and often used for whole carcass roasting), however, had 0.80 times the risk when the HI was 85–92°F compared to a baseline temperature of 54–79°F. The risk of death for roaster swine at a minimum temperature between 40 and 50°F was 1.21 times greater than that of average temperatures ranging from 54 to 79°F. The risk of death for market swine at a minimum temperature range of 40–50°F was 0.97 times that of average temperatures ranging from 54 to 79°F. And for cull sows, the risk of death at a minimum temperature range of 40–50°F was 0.81 times the risk at the average temperature ranging from 54 to 79°F. Across the study period, cumulative foregone revenue, or revenue not realized due to swine condemnations, for all swine was $18.6 million and $4.3 million for cold temperatures and high HI ranges above the baseline, respectively. Marginal foregone revenue per hog in hotter months is higher due to seasonal peaks in swine prices. As a result of this study, the USDA-APHIS swine condemnation surveillance can incorporate weekly estimated HI values and ambient temperature data for slaughter establishments to provide additional information for analysts investigating signals (noteworthy increases above baseline) for “dead” condemnations. This study suggests that current mitigation measures are often not sufficient to prevent swine deaths due to ambient temperature extremes.

Season, Transport Duration and Trailer Compartment Effects on Blood Stress Indicators in Pigs: Relationship to Environmental, Behavioral and Other Physiological Factors, and Pork Quality Traits

Simple Summary

Factors, such as ambient conditions, travel duration and vehicle design/compartment location have an impact on the welfare of pigs during transport, carcass bruises and meat quality. Based on this, we aimed to assess the effects of these factors on blood creatine kinase, lactate and cortisol concentrations in 384 pigs and assess their relationships with trailer temperature, and pigs’ heart rate and gastrointestinal tract temperature, behavior, carcass damage scores and meat quality. Although increased blood cortisol and creatine-kinase levels appear to indicate a physical stress condition in transported pigs, the weak to moderate correlations with environmental and other animal welfare indicators suggest that blood stress parameters can only be used as a complementary measurement in the assessment of the pigs’ response to transport stress.

Abstract

The objective of this study was to assess the effects of the season, travel duration and trailer compartment location on blood creatine-kinase (CK), lactate and cortisol concentrations in 384 pigs and assess their relationships with trailer temperature, heart rate and gastrointestinal tract temperature (GTT), behavior, carcass damage scores and meat quality. Blood CK was greater in pigs transported in summer (p = 0.02), after 18 h transportation (p < 0.001) and in pigs located in C4, C5 and C10 (p = 0.002). In winter, the concentration of blood lactate was higher (p = 0.04) in pigs transported for 6 h in C5. Pigs located in C10 showed higher (p = 0.01) concentration of cortisol than those transported for 18h in C4 in summer. The highest correlations were between blood cortisol and GTT (r = 0.53; p < 0.001), and between blood CK and GTT (r = 0.41; p < 0.001), truck temperature (r = 0.42; p < 0.001), and pH_u in the longissimus muscle (r = 0.41; p < 0.001). In conclusion, although increased blood cortisol and CK levels appear to indicate a physical stress condition in transported pigs, the weak to moderate correlations with environmental and other animal welfare indicators suggest that blood stress parameters can only be used as a complementary measurement in the assessment of the pigs’ response to transport stress.

Effects of the Truck Suspension System on Animal Welfare, Carcass and Meat Quality Traits in Pigs

The objective of this study was to assess the effects of two types of commercial suspension (leaf-spring (LS) vs. air suspension (AS)) installed on two similar double-decked trucks on blood cortisol and lactate concentration, lairage behavior, carcass skin lesions and pork quality traits of 120 crossbred pigs. The suspension type neither influenced pig behaviour in lairage nor blood cortisol and lactate concentrations (p > 0.10). However, when compared with the AS suspension system, the use of LS increased the number of skin lesions in the back and thigh (p = 0.03 and p = 0.01, respectively) and produced thigh with lower pH_u (p < 0.001) and yellower colour (higher b* value; p = 0.03), and paler back muscles (subjective colour; p < 0.05), with a tendency to lower pH (p = 0.06). Therefore, the use air suspension system can improve carcass and meat quality traits of pigs transported to slaughter.

Transport losses in finisher pigs: impact of transport distance and season of the year

OBJECTIVE

The death of animals during transport for slaughter is a major factor indicating the level of welfare in transported animals. The aim of this study was to assess mortality related to the commercial transport of finisher pigs for slaughter in the Czech Republic.

METHODS

The inspectors of the State Veterinary Administration of the Czech Republic recorded the numbers of finisher pigs transported to processing plants in the Czech Republic for slaughter and the mortality in these pigs in relation to transport in the period from 2009 to 2014.

RESULTS

Our results show that the likelihood of death losses in transported pigs increases with increasing transport distance. The transport-related mortality ranged from 0.049% in pigs transported for distances below 50 km to 0.145% in pigs transported for distances exceeding 300 km. The impact of external air temperature on the transport-related mortality found in our study clearly shows that current transport practices fail to ensure the welfare of pigs transported under other than moderate weather. Particularly cold temperatures below -2°C were associated with increased death losses in winter transport.

CONCLUSION

Despite a decreasing trend in the mortality of finisher pigs transported for slaughter in Europe, our study suggests that current transport conditions are not efficient at ensuring the welfare of pigs during transport for longer distances and the protection of pigs against the negative impact of extreme ambient temperatures. Further research should focus on developing practical guidelines to improve the welfare of pigs in transit accordingly.

Welfare measurements of finishing pigs on the day of slaughter: a review

Animal welfare on the day of slaughter is of increasing concern to the authorities and consumers alike, creating a need not only to optimize the welfare of the animals but also to document the level of welfare. The day of slaughter is composed of a variety of stages, initiated when the pigs leave the home pen and including pick-up facilities, transport, lairage, stunning and sticking. At each of these stages, the animals are exposed to different stressors that, both individually and in interaction with one another, can compromise welfare. As part of the initial work aiming to document the welfare of finishing pigs on the day of slaughter, this paper provides an overview of the individual stages including a discussion of potential stressors and potential welfare measurements. These measurements are discussed with regard to their relevance and suitability for documentation of animal welfare on the day of slaughter for development of on-site tools for continuous automatic monitoring of animal welfare.

Effect of Transport Distance and Season on Some Defects of Fresh Hams Destined for DPO Production

Pre-slaughter handling is related to defects in fresh hams that result in exclusion from the DPO Parma chain, including hematomas, lacerations, microhaemorrhages and veining. To determine the effects of transport conditions on hams, we collected data on defects in 901,990 trimmed fresh hams from heavy pigs provided by 3,650 batches from slaughterhouse during 2012 and 2013. For all batches, transport distance (1-276 km) season and year of delivery were considered. A decrease of all defect occurrences was observed for increasing distance up to 170 km (P < 0.05). Above 170 km, however, all defects frequencies increased (P < 0.05). Season showed an effect on the incidence of defects, with an increasing of hematomas and lacerations in winter and autumn respectively (P < 0.05) and the highest percentage of veining and hemorrhages in spring (P < 0.05). Summer had the lowest incidence of defects on fresh hams. We concluded that the incidence of the examined defects and the subsequent rejection for DPO Parma ham production is lower in fresh hams transported 38-170 km during the summer.

Trends in meat science and technology: the future looks bright, but the journey will be long

With an increasing world population, an increase in affluence and a substantial growth in the demand for high quality protein, the meat sector faces a fantastic but challenging century. New scientific knowledge, technology and creative minds are the main ingredients in order to reach out for this great opportunity. Efficiency all the way from breeding and farming to processing and dispatch is crucial for success. Technology has brought us far, and there is still a huge potential for increased efficiency by implementing best practices on a global scale. New challenges include: hyper flexible automation, more accurate and faster measurement systems and meeting special consumer demands already at the production line. Systems for optimal animal welfare will be even more important and sustainability is no longer a consumer trend but a license to operate. The scientific meat society must provide knowledge and technology so we together can reach out for a seemingly bright future.

Welfare of Pigs Being Transported over Long Distances Using a Pot-Belly Trailer during Winter and Summer

Simple Summary

The pot-belly trailer, which can transport large loads in a single journey, is commonly used for swine transportation in Canada. However, it is generally acknowledged that pot-belly trailers and some specific compartments within this vehicle are worse than others in terms of animal losses. The objective of this study was to evaluate the effects of pot-belly design on animal welfare and meat quality in pigs being transported long distance in two different seasons of the year.

Abstract

A total of 2,145 pigs were transported for 8 h in summer (six trips) and winter (five trips) using a pot-belly trailer accommodating pigs in four locations (upper deck or UD, bottom-nose or BN, middle deck or MD and bottom deck or BD). Heart rate of pigs during loading and transportation and lactate and creatine kinase (CK) concentrations in exsanguination blood were measured. Meat quality was evaluated in the Longissimus thoracis (LT), Semimembranosus (SM) and Adductor (AD) muscles. During summer, pigs loaded in the UD and MD had higher (P < 0.05) heart rate at loading compared to those located in the BD and BN. Blood lactate and CK concentrations were higher (P < 0.001) in winter than in summer. Lactate concentration was higher (P = 0.01) in the blood of pigs transported in the BN. Pigs transported in the BN had higher pHu values in the LT, SM and AD muscles (P = 0.02, P < 0.001 and P = 0.002, respectively) and lower (P = 0.002) drip loss values in the SM muscle. This study confirms that some locations within the PB trailer have a negative impact on the welfare of pigs at loading and during transport with more pronounced effects in the winter due to the additive effect of cold stress.

Effects of transport time and location within truck on skin bruises and meat quality of market weight pigs in two seasons

Scheeren, M. B., Gonyou, H. W., Brown, J., Weschenfelder, A. V. and Faucitano, L. 2014. Effects of transport time and location within truck on skin bruises and meat quality of market weight pigs in two seasons. Can. J. Anim. Sci. 94: 71–78. The effects of season (winter vs. summer), transport time (T: 6, 12 and 18 h) and truck compartment (C) on skin bruise score and meat quality were evaluated in 384 pigs distributed across the top front (C1), top back (C4), middle front (C5) and bottom rear (C10) compartments. Bruise score was higher (P=0.01) in winter than in summer. A T×C interaction was found for pHu value in the longissimus thoracis (LT) muscle and for drip loss in the LT and semimembranosus (SM) muscles, with higher (P<0.001) pHu being recorded in the LT muscle and lower drip loss in the LT and SM muscles (P<0.001 and P=0.01, respectively) of pigs located in C10 following 18 h of transport. In summer, higher (P=0.03) pHu values were found in the LT muscle of pigs transported in C4 and lower drip loss in the LT and SM muscles (P=0.04 and P=0.03, respectively) of pigs located in C10. The results of this study suggest that, while skin bruises are only affected by season, the effects of longer transport time and winter temperatures on meat quality can be aggravated by the compartment location.

Effects of transport duration on maintenance behavior, heart rate and gastrointestinal tract temperature of market-weight pigs in 2 seasons

Welfare and meat quality of market-weight pigs may be negatively affected by transport duration and environmental temperatures, which vary considerably between seasons. This study evaluated the effects of 3 transport durations (6, 12, and 18 h) on the physiology and behavior of pigs in summer and winter in western Canada. Market-weight pigs were transported using a pot-belly trailer at an average loading density of 0.375 m(2)/100 kg. Four replicates of each transport duration were conducted during each season. Heart rate and gastrointestinal tract temperature (GTT) were monitored from loading to unloading in 16 pigs from 4 selected trailer compartments (n = 96 groups, total of 384 animals, BW = 120.8 ± 0.4 kg), namely top front (C1), top back (C4), middle front (C5), and bottom rear (C10). Behavior was recorded for pigs (948 and 924 animals, in summer and winter, respectively) in C1, C4, and C5 during transportation (standing, sitting, lying), and during 90 min in lairage (sitting, lying, drinking, latency to rest) for pigs in all 4 compartments. Transport was split into 7 periods: loading, pre-travel (PT), initial travel (IT), pre-arrival 1 (PA1) and 2 (PA2), unloading, and lairage. During IT and PA2, pigs spent less time lying in winter than summer (P < 0.05 and P < 0.05, respectively). During PA1, PA2, and unloading, a greater (P < 0.001) heart rate was found in pigs transported in winter compared with summer. During PA2, pigs subjected to the 18-h transport treatment in winter had a greater (P < 0.05) GTT than the other groups. In lairage, pigs transported for 18 h in winter drank more (P < 0.001) and took longer to rest (P < 0.01) than pigs from other groups. During PA1, pigs transported for 18 h had the greatest GTT (P < 0.001). At unloading, pigs transported for 6 h had the lowest GTT (P < 0.001). In lairage, pigs transported for 18 h spent less time lying than those transported for 6 or 12 h (P < 0.001). These results suggest that in winter, pigs increased their metabolism and were reluctant to rest on cold floors. Pigs transported for 18 h in winter showed greater evidence of thirst. It may be concluded that under western Canadian climatic conditions, long transports (18 h) in cold weather appear to be more detrimental to pig welfare.

Use of infrared ocular thermography to assess physiological conditions of pigs prior to slaughter and predict pork quality variation

Infrared thermography (IRT) body temperature readings were taken in the ocular region of 258 pigs immediately before slaughter. Levels of lactate were measured in blood taken in the restrainer. Meat quality was assessed in the longissimus dorsi (LD), semimembranosus (SM), and adductor muscles. Ocular IRT (IROT) temperature was correlated with blood lactate levels (r=0.20; P=0.001), with pH taken 1hour postmortem (pH1: r=-0.18; P=0.03) and drip loss (r=0.20; P=0.02) in the LD muscle, and with pH1 in the SM muscle (r=-0.20; P=0.02). Potentially, IROT may be a useful tool to assess the physiological conditions of pigs at slaughter and predict the variation of important meat quality traits. However, the magnitude of the correlations is rather low, so a further development of image capture technique and further studies under more variable preslaughter conditions ensuring a larger pork quality variation are needed.