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

Translatomics reveals the role of dietary calcium addition in regulating muscle fat deposition in pigs

Intramuscular fat (IMF) in pork holds significant importance for economic performance within the pig industry and dietary calcium supplementation enhances the accumulation of intramuscular fat. Additionally, calcium ions inhibit translation and reduce protein synthesis. However, the mechanism by which calcium regulates IMF deposition in muscle through translation remains largely unknown. In this study, we compared the ribosome profiles of the longissimus dorsi muscles of Duroc × Landrace × Large white pigs from the normal calcium (NC) group or calcium supplement (HC) group by Ribo-seq, and RNA-seq. By integrating multiple-omics analysis, we further discovered 437 genes that were transcriptionally unchanged but translationally altered and these genes were significantly enriched in the oxidative phosphorylation signaling pathway. Furthermore, experimental data showed that inhibiting the expression of COX10 and mtND4L increased triglyceride accumulation in C2C12 cells, providing new targets for intramuscular fat deposition. Finally, this work links dietary calcium, translation regulation and IMF deposition, providing a new strategy for both meat quality and economic performance within the pig industry.

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.

Association between Enzootic Pneumonia-like Lung Lesions and Carcass Quality and Meat pH Value in Slaughter Pigs

Although the prevalence of respiratory diseases in slaughter pigs ranges from 19% to 74% and continues to be an important concern for swine herds worldwide, only a few studies have investigated the relationship between respiratory disease and pork quality. The general aim of this study was to investigate associations between the prevalence and severity of enzootic pneumonia-like lesions in Polish slaughter pigs on different carcass and meat-quality characteristics at the animal and herd levels. The average prevalence of bronchopneumonic lungs with different degrees of lesions was 94.57%. The majority of lesions indicated the acute stage of enzootic pneumonia. Our results indicate a statistically significant interaction between the mean weight of carcasses depending on the extent of the lesions (p = 0.04) at the animal level. The correlation between meatiness and severity of lung lesions was r = -0.25 (p = 0.00). The correlation between the extent of lung lesions and pH₄₅ value was r = -0.17 (p = 0.005) on the animal level and r = -0.63 (p = 0.017) at the herd level. This implies that lung lesions in slaughter pigs negatively influence not only animal health and welfare, but also carcass quality.

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.

Impact of Procedures and Human-Animal Interactions during Transport and Slaughter on Animal Welfare of Pigs: A Systematic Literature Review

Animal welfare is a high social and political priority and is enshrined in European and national legislation. This systematic literature review (funded by the German Ministry of Food and Agriculture; grant no. 2817806A18) was conducted to find animal and management-based indicators that could be influenced by changes in pig handling and management procedures on the day of slaughter and, therefore, will directly result in improved animal welfare. For this systematic literature review, following the PRISMA guidelines, we conducted a structured literature search using the databases PubMed^®, Web of Science^TM, and LIVIVO with set search terms and their combinations in German and English. Only peer-reviewed original articles from European countries from 2009 until 2022 that dealt with welfare during transport and/or slaughter of fattening pigs and offered potential measurable indicators on the basis of the animal or management, and either directly or indirectly recommended handling practices were included. We used the literature management system EndNote^TM, and after duplicate removal, a total of 1099 records were found for further analysis. After analysis and discussion in the review team, which consisted of three experts in total, 105 articles underwent full-text screening. Finally, 39 articles were included in the results for this systematic literature review. According to this systematic literature review, the following procedures have a positive impact on the animal welfare of pigs on the day of slaughter. Calm-rather than rough-handling of pigs was the most influential factor. This can be achieved by using animal-friendly driving aids. Loud noise should be avoided in general or reduced as far as possible. Transport time is not always influenceable, but shorter transport duration with stocking density as stated by the European regulations as a maximum will reduce stress in pigs. Our review showed that there are differing scientific results about lairage duration, although this should be set in relation to prior stress and transport time. Knowledge of good stunning parameters, such as gas concentration, exposure time to the gas, recommended amperage, and current flow duration is essential. If electrical stunning is performed, the correct attachment of electrodes is crucial. The control of stunning effectiveness is extremely important to avoid suffering and pain, with the proviso that it is assessed on the basis of multiple parameters. The corneal reflex, regular gasping, and the up-righting reflex could be assessed together. Certificates of competence and continuing educational programmes for the personnel form the basis of animal-friendly handling and a stressless slaughter routine. It can be assumed that the results of this systematic literature review reflect the state of current research of pig welfare during transport and slaughter in the European Union, even though it must be assumed that not all relevant points were covered by the review, which can be seen as a limitation at the same time because important non-European or older publications could not be included.

Fasting Finisher Pigs before Slaughter Influences Pork Safety, Pork Quality and Animal Welfare

The final phase in pork production is the transport of finisher pigs to the slaughterhouse. Fasting is one of the parameters that influence the stress coping ability of the pigs during transport and lairage. When implemented correctly with attention to the local factors, pre-slaughter fasting can improve animal welfare, pathogen risk and carcass hygiene. The length of pre-slaughter feed withdrawal time is important to the success of the production practice. In practice, a fasting time before slaughter between 12 and 18 h enhances pork safety, pork quality, and animal welfare. This means that communication between producer and slaughterhouse is essential when planning the fasting and lairage times to avoid carcass and technological pork quality problems (such as pale, soft, and exudative (PSE) meat or dark, firm and dry (DFD) meat).