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

South African Journal of Animal Science, Feb 2019

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, pH45 value and the incidence of DFD meat; while high stocking density decreased pH45 value and increased T45 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, pH45 value and the incidence of DFD meat became higher. After short lairaging, the pH45 value was lower, while the incidence of PSE meat increased. Pigs slaughtered in winter had the highest slaughter weight, backfat thickness, pH45 value and incidence of DFD, and the lowest meatiness. Pigs slaughtered in summer had the lowest slaughter and carcass weights and pH45 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.

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

Effects of various pre-slaughter conditions on pig carcasses and meat quality in a low-input slaughter facility     N. ČobanovićI, #; M. BoškovićI; D.VasilevI; M. DimitrijevićI; N. ParunovićII; J.DjordjevićI; N. KarabasilI IFaculty of Veterinary Medicine, University of Belgrade, 11000 Belgrade, Serbia IIInstitute of Meat Hygiene and Technology, Belgrade, 11000 Belgrade, Serbia     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, pH45 value and the incidence of DFD meat; while high stocking density decreased pH45 value and increased T45 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, pH45 value and the incidence of DFD meat became higher. After short lairaging, the pH45 value was lower, while the incidence of PSE meat increased. Pigs slaughtered in winter had the highest slaughter weight, backfat thickness, pH45 value and incidence of DFD, and the lowest meatiness. Pigs slaughtered in summer had the lowest slaughter and carcass weights and pH45 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. Keywords: DFD meat, gender, lairage time, low-input slaughter system, PSE meat, season, slaughter weight, stocking density     Introduction Appropriate pre-slaughter treatment of pigs is of great importance, from the standpoint of animal welfare and carcass and meat quality (Gajana et al., 2013). The way in which pigs react to pre-slaughter stress depends on factors such as handling during loading and unloading, mixing pigs from different pens, stocking density, time of transportation and lairaging, feed and water deprivation, and the season of slaughter (Dalla Costa et al., 2007, Karabasil et al., 2013a; 2013b). Intense stress immediately prior to slaughter, provoked by inadequate treatment, depletes muscle glycogen, and contributes to rapid glycolysis, with increased lactic acid production early post mortem. Hence, skeletal muscles of acutely stressed pigs show an excessively fast drop in pH value in the first 60 minutes post mortem, which, in combination with high carcass temperature, results in pale, soft and exudative (PSE) meat (Adzitey & Nurul, 2011). On the other hand, when pigs are subjected to chronic stress, their muscle glycogen stores are reduced, leading to lower production of lactic acid, and resulting in dark, firm and dry (DFD) meat (Gajana et al., 2013). It has been reported that stocking density during transportation is a key factor, which can lead to negative effects on animal welfare and meat quality (Pereira et al., 2015), since high- and low-stocking density are both known to increase stress, and have detrimental effects (Guárdia et al., 2004, 2005). The results from earlier studies suggest that lairage time is an important source of variations that determine meat quality (Nanni Costa et al., 2002). After short lairaging (<1 h), meat was paler, and had a lower pH value and water-holding capacity, which is typical of PSE meat (Warriss et al., 1998). When pigs were kept in lairage overnight, carcass weight, backfat thickness and meat temperature were reduced, compared with short large time (Warriss et al., 1998). Likewise, the frequency of carcasses with skin lesions and the prevalence of DFD meat increased progressively with longer lairage (Warriss et aí., 1998). Adverse weather conditions have an impact on ante- and post-mortem muscle glycogen stores, which leads to higher incidences of bruised carcasses and DFD meat in winter, while animal losses and the risk of PSE meat increase in summer (Guárdia et aí., 2004, Guárdia et aí., 2005, Chulayo & Muchenje, 2015). Several studies showed that an increase in the slaughter weight of fattening pigs diminishes carcass and meat quality characteristics (Cisneros et aí., 1996, Latorre et aí., 2004, Czyzak-Runowska et aí., 2015). Nonetheless, this view was not supported by all surveys conducted in this area (Correa et aí., 2006, Łyczyński et aí., 2006). The influence of gender on carcass and meat quality traits has been extensively investigated over the last decades, but the results are not consistent. Some auth (...truncated)


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N. Čobanović, M. Bošković, D.Vasilev, M. Dimitrijević, N. Parunović, J.Djordjević, N. Karabasil. Effects of various pre-slaughter conditions on pig carcasses and meat quality in a low-input slaughter facility, South African Journal of Animal Science, pp. 380-390, Volume 46, Issue 4, DOI: 10.4314/sajas.v46i4.6