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

Heat/Cold Stress and Methods to Mitigate Its Detrimental Impact on Pork and Poultry Meat: A Review

This paper aims to provide an updated review and current understanding of the impact of extreme temperatures-focusing on heat stress (HS)-on the quality of pork and poultry meat, particularly amidst an unprecedented global rise in environmental temperatures. Acute or chronic HS can lead to the development of pale, soft, and exudative (PSE) meat during short transportation or of dark, firm, and dry (DFD) meat associated with long transportation and seasonal changes in pork and poultry meat. While HS is more likely to result in PSE meat, cold stress (CS) is more commonly linked to the development of DFD meat. Methods aimed at mitigating the effects of HS include showering (water sprinkling/misting) during transport, as well as control and adequate ventilation rates in the truck, which not only improve animal welfare but also reduce mortality and the incidence of PSE meat. To mitigate CS, bedding on trailers and closing the tracks' curtains (insulation) are viable strategies. Ongoing efforts to minimize meat quality deterioration due to HS or CS must prioritize the welfare of the livestock and focus on the scaleup of laboratory testing to commercial applications.

Prevalence of carcass lesions and their effects on welfare, carcass composition and meat quality in slaughtered pigs

The aims of this study were to determine the prevalence of carcass lesions in slaughtered pigs and to quantify their relationships with different animal characteristics, pre-slaughter factors, blood measurements, performance indices, carcass composition and meat quality traits. Data was recorded for 30 journeys referring to 1080 market-weight pigs that originated from 15 commercial small-scale finishing farms. Carcass lesions were visually assessed on the slaughterline in different parts of the carcass, i.e., anterior, middle and posterior, using a three-point scale. Complete blood count was investigated. The following performance indices and carcass composition traits were measured: average lifetime daily weight gain, live, hot and cold carcass weights, cooler shrinkage, dressing percentage, backfat thickness and meatiness. Meat pH and temperature were measured 45 minutes postmortem. Of the 1080 pigs slaughtered in 30 batches, 70.28% displayed some degree of lesions on the carcass (moderate – 30.00%; severe – 40.28%). The carcass lesions were the most prevalent (50.20%) in the posterior part of the pig carcass. RYR1 genotype, live weight, loading density, lairage time, lairage density and slaughter season affected the carcass lesion prevalence. The presence of carcass lesions, irrespective of severity, was associated with alterations in blood measurements in slaughtered pigs, indicating compromised animal welfare. The presence of severe carcass lesions in slaughtered pigs was significantly associated with increased meat pH45min, which led to the highest occurrence of dark, firm and dry pork. In contrast, there was strong evidence of association between the presence of moderate carcass lesions in slaughtered pigs and both decreased meat pH45min and increased meat T45min, which led to the highest occurrence of pale, soft and exudative pork among the carcass lesion groups. In conclusion, this study showed a high prevalence of carcass lesions in slaughtered pigs, whereby the risk of their occurrence was affected by both animal characteristics and pre-slaughter conditions. Also, the presence of carcass lesions in slaughtered pigs, irrespective of severity, was significantly associated with alterations in the blood measurements and pork quality.

Literature Review on the Pre-Slaughter Welfare of Italian Heavy Pigs

Simple Summary

Italian heavy pigs production differs from pig farming in other countries of the world mainly due to the high body weight and age at slaughter of the animals. This implies that peculiar animal needs may be addressed to achieve a high level of animal welfare during the pre-slaughter phases. This narrative review aims to collect the available information on welfare issues of Italian heavy pigs in the pre-slaughter phases, and to highlight recent findings and knowledge gaps.

Abstract

This work provides a narrative review of the available information on the welfare of Italian heavy pigs in the pre-slaughter phase (transport, lairage, and stunning). The meat from these pigs is used for specific PDO (Protected Designation of Origin) products, and the production rules for these specialties require higher body weight (160–170 kg) and age (in general more than 9 months) at slaughter than in most other countries. This may lead to specific behavioral and physiological needs of pigs. The present paper summarizes the main research findings and knowledge gaps for each of the pre-slaughter phases. Studies are presented according to the four principles of the Welfare Quality assessment protocol (good feeding, good housing, good health, and appropriate behavior). The results of the literature review indicate a lack of knowledge on several aspects. Most of studies were carried out in a single slaughterhouse, making it difficult to identify risk factors and confounding effects. Moreover, animal-based measures were assessed using different protocols, reducing the possibility of comparison across studies. These findings may serve as a basis for the development of specific research studies and policies aimed at enhancing the animal welfare level and the ethical attributes of this renowned production, also in accordance with consumers’ expectations.

Combined effects of weather conditions, transportation time and loading density on carcass damages and meat quality of market-weight pigs

This study investigated the interactive effects of weather conditions, transportation time and loading density on carcass damages and meat quality traits of market-weight pigs under commercial conditions. The following pork quality parameters were measured: pH and temperature; colour; drip, thawing and cooking loss; and textural traits. Pigs were assigned to one of eight groups arranged in a 2 × 2 × 2 factorial design according to the weather conditions (hot and cold), transportation time (short and long) and loading density (high and low). A three-way ANOVA and Tukey's post-test (multiple comparisons) were performed to assess the differences between groups in examined pork quality traits. Pigs exposed to short transportation (∼ 20 min) at high loading density (0.29 m2/100kg) during hot weather conditions produced meat with the lowest initial and ultimate meat pH value and sensory colour scores, and the highest initial temperature and the occurrence of pale, soft and exudative pork. The occurrence of pale, soft and exudative pork was reduced 5-fold during hot weather conditions when pigs were exposed to longer transportation (∼ 210 min) and low loading density (0.53 m2/100kg). Pigs exposed to short transportation (∼ 20 min) at high loading density (0.41 m2/100kg) during cold weather conditions produced the highest quality pork (the highest percentage of red, firm and non-exudative pork) characterised by lowest drip loss and b∗ value and the highest sensory colour scores. The highest percentages of carcass damages were recorded in pigs exposed to both low (0.50 m2/100kg) and high (0.33 m2/100kg) loading density during long transportation (∼ 210 min) in cold weather conditions. In conclusion, weather conditions and loading density are of greater importance for the occurrence of carcass damages and pork quality variation than transportation time.

The multivariate approach identifies relationships between pre-slaughter factors, body lesions, ham defects and carcass traits in pigs

Abattoir meat inspection has been proposed for the collection of welfare outcomes. The identification of suitable animal-based measures (ABM) is still a critical point that needs to be implemented to avoid collinearity among measures. The present study aims to benchmark the presence of ABM such as skin and tail lesions and ham defects in carcasses from 79 batches of Italian Heavy pigs and to identify possible relationships between the assessed ABM and pre-slaughter factors such as the season and the overnight lairage. Furthermore, the study also considers the effect of pre-slaughter conditions and ABM on carcass traits parameters (cold carcass weight and lean meat percentage). Skin and tail lesions were recorded at the slaughter line. The presence of abscesses, muscle tears and veining defects were assessed in the hams at trimming, according to the Parma Ham Consortium. A multivariate analysis was performed to identify relationships between ABM and pre-slaughter factor; therefore, a linear model was built to assess the effect on carcass weight and lean meat percentage. Main welfare issues were represented by skin and tail lesions and muscle tears (prevalence above 10%). Multivariate analysis evidenced that skin lesions and veining defects were mostly associated with the warm season. Abscesses and muscle tears in the hams were more likely related to overnight lairage, while tail lesions contributed equally to both season and lairage. Moreover, lairage related factors showed to affect lean meat percentage. The findings of the present study suggest that ham defects might be useful indicators of pre-slaughter stress. The validation of these findings with physiological parameters could be of interest for further studies.

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.

Skin lesion monitoring at slaughter on heavy pigs (170 kg): Welfare indicators and ham defects

In order to evaluate at the slaughterhouse external carcass lesions on heavy pigs (170 kg) as potential welfare indicators, and the prevalence of ham defects determining ham exclusion from Protected Designation of Origin (PDO) markets, 732 pig batches from northern Italy were monitored during a 12-month period, and then processed analysing the effect of slaughter season, overnight lairage, and production type. On the slaughter line, skin scratches were separately scored in the posterior region (defined as the area including the hind legs and the tail) and the anterior one (as the remaining area), while the whole carcass was examined for external hematomas. Chronic ear and tail lesions referable to the rearing phase, and bursitis were recorded as retrospective welfare indicators. The annual median prevalence of carcasses per batch with severe anterior scratches was 64% while 46.4% had severe posterior scratches. The highest autumn score for both skin scratches (P < 0.001) and traumatic ham defects (P = 0.005) is reflected in the positive correlation between severe posterior scratches and ham hematomas (r² = 0.27; P < 0.001). Overnight lairage batches resulted in higher prevalence for scratches, while among ham defects only veining increased. Among binary records, only ear lesions were frequently recorded (annual median = 10%). A comparison analysis between pigs in and out of PDO circuit was performed to evaluate the variation related to the different genetics, showing differences for ear and tail lesions and for almost all the considered ham defects. The present study confirms that skin lesions represent a problem also for heavy pigs and that overnight lairage and season can affect their prevalence, with the associated possibility to give ham defects. Ear lesions are suitable to be used as retrospective welfare indicator, while tail lesions usage is nowadays limited by the extensive use of tail docking.

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.