Correlations among Stress Parameters, Meat and Carcass Quality Parameters in Pigs

Abstract

Relationships among different stress parameters (lairage time and blood level of lactate and cortisol), meat quality parameters (initial and ultimate pH value, temperature, drip loss, sensory and instrumental colour, marbling) and carcass quality parameters (degree of rigor mortis and skin damages, hot carcass weight, carcass fat thickness, meatiness) were determined in pigs (n = 100) using Pearson correlations. After longer lairage, blood lactate (p<0.05) and degree of injuries (p<0.001) increased, meat became darker (p<0.001), while drip loss decreased (p<0.05). Higher lactate was associated with lower initial pH value (p<0.01), higher temperature (p<0.001) and skin blemishes score (p<0.05) and more developed rigor mortis (p<0.05), suggesting that lactate could be a predictor of both meat quality and the level of preslaughter stress. Cortisol affected carcass quality, so higher levels of cortisol were associated with increased hot carcass weight, carcass fat thickness on the back and at the sacrum and marbling, but also with decreased meatiness. The most important meat quality parameters (pH and temperature after 60 minutes) deteriorated when blood lactate concentration was above 12 mmol/L.

Stress Effects on Meat Quality: A Mechanistic Perspective

“…Previous studies indicated that holding pigs in lairage for more than 1 h can reduce the PSE defect, while the occurrence of DFD and skin damage increased with the extension of lairage time (Costa, Fiego, Dall'Olio, Davoli, & Russo, ; Warriss, Brown, Edwards, & Knowles, ). A recent study also indicated that longer lairage time was highly correlated with increased blood lactate content and blemishes on the skin; meanwhile, the meat color turned darker (Dokmanovic et al., ). Moreover, long holding times increased carcass exposure to cross contamination by pathogenic bacteria (Warriss, ).…”

Identifying Physiological Stress Biomarkers for Prediction of Pork Quality Variation

“…Cooking loss was estimated by weighing them before and after cooking. Rigor mortis intensity was determined on the left carcass side 45 min postmortem by measuring the degree of angle between the body axis and foreleg according to Dokmanović et al's method [13]. For this purpose, photographic images of carcasses were taken at a distance of approximately 2 m and a height of 160 cm, parallel to the plane in which the carcasses were held.…”

“…Although several studies have investigated the relationship between cortisol concentration and pork quality, the results are not consistent. Several studies reported that the increase in cortisol level was associated with higher meat pH, darker meat color, lower drip loss, and higher occurrence of dark, firm, and dry (DFD) pork [13][14][15]. In contrast, other researchers reported that higher cortisol level was related to a faster muscle pH decline, lighter meat color, lower water holding capacity, bringing as a consequence the occurrence of PSE pork [7,16].…”

“…Non-invasive, quick, accurate, and reliable on-site prediction of pork quality would facilitate the distribution of whole carcasses or carcass cuts for fresh pork, different processing sectors (dry-cured ham or sausage production), or for meat branding (e.g., premium meat, meat products with protection of geographical indications, protected designations of origin, and guaranteed traditional specialty) according to their intrinsic characteristics and potential quality value. To date, several studies [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] have investigated physiological stress biomarkers as potential predictors of meat quality, as indicated previously. However, the high inconsistency of results reflects the complexity of meat quality traits, which are affected by multiple interacting factors, including genetic background, breeding, environmental factors, preslaughter conditions, as well as slaughtering procedures.…”

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“…Dokmanović et al [38] correlated different categories of animal stresses, meat quality, and carcass quality characteristics in pigs and found that cortisol affected the carcass quality. High cortisol values in beef cattle resulted in high pH but cooking loss values were still within the normal range [39].…”