The effect of transport density and gender on skin temperature and carcass and meat quality in pigs

Abstract

Pre-slaughter handling of pigs established properly is very important, not only from the point of view of welfare, but also for the quality of meat. The aim of present research was to evaluate the effect of gender and density of pigs during their transport to the abattoir on the skin temperature and carcass and meat quality. Were used 192 (115.54 ± 6.03 kg) finishing pigs to investigate the effects of gender (barrows and gilts) and transport densities for slaughter (236, 251, and 275 kg/m²) on the skin temperature and carcass and meat quality. Average skin temperature between genders and transport densities at any point of time during pre-slaughter did not differ. Skin temperatures before unloading had the highest average value relative to all other time points, followed by immediately after unloading and remaining the same for the next 2 h. Lowest skin temperature value was registered on pigs at the pre-slaughter time followed by farm and at loading times. Pigs transported with different densities did not show differences for the skin carcass lesions. Meat from pigs transported at 275 kg/m² presented higher frequency of red, soft, exudative (RSE) and lower of red, firm, non-exudative (RFN) classes as compared to those for other densities. Animals transported at 236 and 251 kg/m² did not differ as the frequency of RSE and RFN meat. Skin temperature of pigs oscillate along the pre-slaughter times and the pre-slaughter transport of pigs at 236 and 251 kg/m² generates less frequency classes of faulty pork, although difference in the densities did not have any effect on the skin temperature and skin lesions.

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

“…This can be ascribed to the fact that entire males are more aggressive and more sensitive to stress than gilts and castrated male pigs, especially in unstable social settings when mixed with unacquainted animals and, therefore, have a higher predisposition for pre-slaughter fights and are more prone to suffer carcass lesions and fighting-type bruises (Dokmanović et al, 2017;Teixeira and Boyle, 2014). However, some researchers (Driessen et al, 2020b;Mota-Rojas et al, 2006;Pereira et al, 2017;Sutherland et al, 2009) found that barrows suffered more carcass lesions, especially in the anterior part, suggesting that they were more prone to fights, probably as a consequence of the greater agitation and restlessness as compared to gilts. Other authors (Dokmanović et al, 2017) reported a higher prevalence of carcass lesions in gilts, indicating that they show higher levels of fighting behaviour compared to castrated male pigs.…”

“…In this study, the highest percentages of severe lesions and lesions on the anterior and posterior parts of the carcass were recorded in pigs exposed to low loading density (>0.50 m 2 /100 kg). In the case of low loading density combined with poor road surfaces and/or careless driving, which consists of sudden acceleration and, hence, violent braking, pigs experience difficulties in standing up, lose balance, topple, slip and use excessive corrective muscular action, resulting in falling, trampling, knocks against the body and the occurrence of skin lesions (Driessen et al, 2020 a, b;Pereira et al, 2017;Sionek and Przybylski, 2016). Also, when the lorry comes to a halt, pigs exposed to low loading density are no longer occupied by keeping themselves balanced, but redirect their attention to their pen mates to fight out a new dominance hierarchy, which further increases carcass lesion scores (Driessen et al, 2020c).…”

“…Also, when the lorry comes to a halt, pigs exposed to low loading density are no longer occupied by keeping themselves balanced, but redirect their attention to their pen mates to fight out a new dominance hierarchy, which further increases carcass lesion scores (Driessen et al, 2020c). Contrarily, overcrowding during transportation prevents the pigs from lying down, so they disturb each other to find a space to rest, which causes fighting and mounting between pigs, leading to injuries on the shoulder and back with teeth and the forelimb hoofs (Faucitano et al, 2001;Pereira et al, 2017;Sionek and Przybylski, 2016), which can explain the highest percentages of severe lesions and lesions on the anterior and middle parts of the carcass in pigs exposed to high loading density (<0.35 m2/100 kg). According to the results of this study, the high risk of carcass lesions is related to both high (<0.35 m 2 /100 kg) and low (>0.50 m 2 /100 kg) loading densities, and, therefore, it is recommended to work with medium loading density (0.40-0.45 m 2 /100 kg), such as those suggested by the European Union (EU) regulations (European Commission, 2005).…”

“…Also, penalties may be imposed by the official meat inspectors or abattoir organisations (Driessen et al, 2020 a). Considering that areas of the carcass with skin lesions necessitate trimming during postmortem processing, the abattoirs bear financial losses due to poor presentation, decreased yield and grade of the carcass, and depending on lesion anatomical location, potential devaluing of primary carcass cuts (Driessen et al, 2020 a;Pereira et al, 2017;Teixeira and Boyle, 2014). Furthermore, abattoir financial losses arise from the rejection of pork from the high-quality markets, because meat obtained from slaughtered pigs with carcass lesions is not acceptable to consumers or for processing, as it yields a poor product, which requires meat producers to discount the value of carcass or primary carcass cuts and, consequently, ends up in the wastage of the product (Faucitano et al, 2001).…”

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

“…Most pigs begin to sit and lie down during the first half hour of transport, especially during hot weather conditions either due to heat exhaustion or in attempts to maximise heat loss through contact with the lorry floor or wall surface (Faucitano and Goumon, 2018;Rioja-Lang et al, 2019). Therefore, when provided more transportation time (> 3 h) with sufficient floor space, pigs may acclimate on transport conditions and partially recover from the stress induced during loading, so the transport vehicle could act as a resting place similar to the lairage pens in the abattoir, which is of great importance for decreasing the occurrence of PSE pork (Pérez et al, 2002;Chai et al, 2010;Faucitano and Goumon, 2018). Also, the results of this study confirmed that the recommended loading density (0.425 m 2 /100 kg) during warmer weather conditions (> 25 • C) should be decreased by 20 % to reduce transport stress and improve pork quality ( Čobanović et al, 2016b;Nannoni et al 2017).…”