Effects of various pre-slaughter conditions on pig carcasses and meat quality in a low-input slaughter facility

Abstract

The aim of this study was to determine the effects of gender, slaughter weight, stocking density, lairage time and season on carcass and meat quality parameters in a low-input production system. The study was conducted on 400 slaughter pigs (200 barrows and 200 gilts) with live weight of 115.0 ± 4.70 kg. Barrows had higher slaughter and carcass weights, fat thickness and lower meatiness. Heavier pigs had higher hot and cold carcass weights, fat thickness, lower meatiness, and higher incidences of pale, soft and exudative (PSE) and dark, firm and dry (DFD) meat. Low stocking density during transportation increased skin lesion score, pH 45 value and the incidence of DFD meat; while high stocking density decreased pH 45 value and increased T 45 value and the incidence of PSE meat. Long lairaging reduced slaughter weight, carcass weight, dressing percentage and backfat thickness and increased skin lesion score. After overnight lairaging, pH 45 value and the incidence of DFD meat became higher. After short lairaging, the pH 45 value was lower, while the incidence of PSE meat increased. Pigs slaughtered in winter had the highest slaughter weight, backfat thickness, pH 45 value and incidence of DFD, and the lowest meatiness. Pigs slaughtered in summer had the lowest slaughter and carcass weights and pH 45 value, and the highest incidence of PSE meat. In conclusion, gender influenced carcass quality, slaughter weight and lairage time, and season affected carcass and meat quality, while stocking density had an impact on meat quality.

Identifying Physiological Stress Biomarkers for Prediction of Pork Quality Variation

“…As mentioned before, more than a third of the examined slaughter pigs (31.25%) had fighting-type bruises on their carcasses, probably as a consequence of aggressive behavior caused by adverse weather conditions on the day of slaughter. During this investigation, pigs slaughtered in summer and winter were exposed to extreme weather conditions, such as high relative humidity (76.2-84.5%) and environmental temperatures above (29.5 to 35.0 • C) or below (−9.5 to −5.5 • C) the thermoneutral zone for slaughter weight pigs (15-25 • C, [4]). When the environmental temperature exceeds the upper threshold of thermal tolerance, the resting time is interrupted and pigs start to search for cool areas to lie down without contact with other individuals [46].…”

“…If this is not possible, pigs become agitated, which increases aggression between pen-mates [46]. When the environmental temperature falls below the lower threshold of thermal tolerance, pigs tend to maintain body temperature by lying in close proximity to each other to create a warmer microclimate [4,45]. However, grouping of pigs decreases the space allocation, which increases fights between pen-mates trying to find a place to rest [4,45].…”

“…When the environmental temperature falls below the lower threshold of thermal tolerance, pigs tend to maintain body temperature by lying in close proximity to each other to create a warmer microclimate [4,45]. However, grouping of pigs decreases the space allocation, which increases fights between pen-mates trying to find a place to rest [4,45]. Therefore, both heat and cold stress could provoke fighting behavior in pigs, resulting in carcass lesions, muscle damage, and pork quality deterioration.…”

“…The day of slaughter has been identified as one of the most stressful stages in a pig's life, which negatively affects pig health, welfare, carcass characteristics, and meat quality [1][2][3][4][5]. This is because pigs are inevitably exposed to handling, loading, transportation, unloading, adverse weather conditions, mixing with unfamiliar animals, and physical and emotional stress owing to the new accommodation [6].…”

Blood parameters, carcass and meat quality of slaughter pigs with and without liver milk spots

“…The presence of Ascaris suum infection and liver milk spots can lead to the following negative effects: (1) farm economic losses attributed to decreased daily weight gain, anthelmintic treatment costs, depressed growth rates and feed conversion efficiency (Sanchez-Vazquez et al, 2010), (2) changes in hematological values (Makinde et al, 1996;Zanga et al, 2003;Wieczorek et al, 2006), (3) slaughterhouse operator losses due to trimmings and disposal of organs unsuitable for human consumption (Pyz-Lukasik and Prost, 1999), (4) lower carcass and pork quality (Theodoropoulos et al, 2004;Knecht et al, 2011Knecht et al, , 2012. A number of studies revealed that pork quality is affected by many different factors, such as feeding, slaughter weight and gender, pre-slaughter and slaughter conditions (Šefer et al, 2015;Rocha et al, 2016;Đorđević et al, 2016;Čobanović et al, 2016b, 2016c. However, only one published article is available in the literature about the relationship between liver milk spots and pork quality (Theodoropoulos et al, 2004).…”