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

Effects of Stocking Density in the Pen and Lairage Time on Blood Stress Indicators, Skin Lesion Scores, and Pork Meat Quality

The objective of this study was to assess the effects of stocking density in the pen and lairage time before slaughter on blood stress indicators, skin lesions, and pork meat quality traits. A total of 1920 immunocastrated male pigs were shipped to a slaughterhouse. In order to maintain the proposed stocking densities, 72 pigs out of the 1920 animals were removed across loads from the experiment. The remaining 1848 pigs were randomly assigned to two different stocking densities in the lairage pen (0.42 m2/100 kg and 0.66 m2/100 kg) and two lairage times (2 h and 6 h). A total of 360 pigs were selected for the analysis of exsanguination blood glucose, creatine kinase, lactate dehydrogenase, cortisol concentration, hematocrit percentage, and carcass skin lesion scores, whereas meat quality was assessed in 240 loin muscles. Except for blood hematocrit percentage, the interaction stocking density × lairage pen had no effect on any parameter (p > 0.10). When compared to a lower stocking density (0.66 m2/100 kg), pigs kept at a higher stocking density (0.42 m2/100 kg) tended to present lower blood LDH concentrations (p = 0.06) and higher blood cortisol concentrations (p = 0.08) at slaughter and had greater carcass skin lesion scores (p < 0.001) and drier (lower drip loss) loin muscles (p = 0.04). Increased blood hematocrit percentage was found in pigs kept in lairage at a higher stocking density for 6 h when compared with the other lairage conditions (p < 0.01). Overall, stocking density, in particular when it was high, influenced more pigs' stress conditions at slaughter and carcass and meat quality than the time spent in lairage.

Assessment of pig welfare at slaughterhouse level: A systematic review of animal-based indicators suitable for inclusion in monitoring protocols

Pig welfare constitutes a strategic pillar of sustainability within the pork industry. Consequently, there is a need to identify, develop and/or validate indicators for assessing pig wellbeing under commercial conditions. A systematic review following PRISMA guidelines identified 95 pig welfare indicators (PWIs) categorized into physiological, behavioral, health and post-mortem, and product quality. The review evaluated their validity and feasibility (V&F) for use in abattoirs to measure welfare during transport and slaughter. Thirty V&F indicators were found: one physiological (body temperature), 12 behavioral (human-animal relationship, aggression, falling, vocalization, slipping, panting, lying down, sitting, turning back), 13 health and post-mortem (presence of entry points, hernias, body lesions, ear lesions, tail lesions, pericarditis, pneumonia, bursitis, lameness, dead animals, walking and non-walking animals), and four product quality (pH, bruises, body condition, carcass weight). This information might help to identify the factors that affect the risk level of particular pig welfare problems, thereby aiding in the application of risk-based strategies.

Effects of Stocking Density and Illuminance in Lairage of Fattening Pigs in Different Temperatures

This study investigated the effects of lairage conditions on the welfare and meat quality of pigs during lairage periods. A total of 3070 finishing pigs were assigned to one of six groups arranged in two trials in a 2 × 3 factorial design according to the illuminance (under 40 lux (LX), over 40 lux (HX)) and stocking density (low density (LD), higher than 0.83 m2/100 kg; normal density (ND), 0.50-0.83 m2/100 kg; high density (HD), lower than 0.50 m2/100 kg) with high temperature (HT), higher than 24 °C; low temperature (LT), lower than 10 °C. Pigs stocked with HD showed lower aggression behavior and overlap behavior than those stocked with LD at LT. Pigs stocked with HD showed higher standing, sitting, and aggression behavior than those stocked with LD at HT. Pigs stocked with HD showed higher pH than those stocked with LD at LT. At HT, pigs stocked with LD showed higher pH, WHC, DL, and CL than those stocked with HD. At LT, pigs stocked with LD showed higher cortisol levels than those stocked with HD. However, pigs stocked with LD showed lower cortisol levels than those stocked with HD at HT. Based on the obtained results, stocking of too-high (lower than 0.50 m2/100 kg) density at HT and stocking of too-low (higher than 0.83 m2/100 kg) density at LT are generally not good for meat quality and animal welfare.

Implications of Lairage and Environmental Enrichment on Behavioral Responses and Skin Lesions in Finishing Pigs in a Slaughterhouse

Different resources, such as environmental enrichment, are being evaluated in order to minimize animal stress and promote better conditions during the life cycle of animals, as consumers are increasingly concerned about animal welfare issues. Lairage represents an important stage in the swine production chain and is directly related to animal welfare. The aim of this study was to evaluate the effect of lairage time in the slaughterhouse and environmental enrichment on the level of skin lesions and behavioral responses in pigs. A total of 648 finishing pigs of both sexes were assessed before and after lairage at the slaughterhouse with a five-point scale (0 = none, to 4 = ≥16 superficial lesions or >10 deep lesions). After lairage (after slaughter), lesions were also classified according to their source (mounting, fighting, and handling). Pigs were distributed into two treatments groups during lairage: with environmental enrichment (EE) on the pen, with hanging metal chains, and with no enrichment (NE). Behavior was monitored during the first four hours of lairage. Proportional odds, mixed linear model for longitudinal data, and non-parametric Wilcoxon signed rank tests were used to analyze the relation between treatments, skin lesions, and behavior. The simple metal chains did not affect skin lesion score or pigs' behavior (p > 0.05), whereas lairage duration influenced standing (SA), sitting (S), lying (L), idleness (I), and drinking water (D) (p < 0.001). The main source of skin lesions was handling, which did not differ between treatments (EE and NE) (p > 0.05). It was observed that the severity of the lesions (highest scores of 3, 4, and 5) increased in the different anatomical regions of the pigs when compared before and after slaughter, with the exception of the frontal area, which was the same (p = 0.7547). Lairage time has a proportional relation with skin lesions, and hanging chains at the slaughterhouse pens was not enough to reduce the number of lesions and to change pig behavior.

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).