Correlations among various blood parameters at exsanguination and their relationships to pork quality traits

Abstract

The objectives of this study were to investigate the correlations between various blood parameters compared with cortisol and lactate levels under the standard pre-slaughter procedure and handling conditions and to assess their potential as indicators of pork quality traits. Despite there being no additional pre-slaughter stress treatment, there is considerable variation in blood parameters at exsanguination. Serum cortisol and blood lactate levels, widely used indicators of stress, were positively correlated with blood glucose and electrolytes, such as calcium, potassium and sodium. Moreover, these parameters were significantly correlated with a rapid rate of early postmortem glycolysis and reduced water-holding capacity. In particular, blood lactate and glucose levels significantly differed between porcine quality classes. However, other blood parameters including electrolytes did not significantly differ between quality classes though they significantly correlated with pork quality traits. Therefore, serum cortisol, blood lactate and glucose have potential as indicators of the rate and extent of postmortem metabolism and ultimate pork quality under the standard procedure and handling conditions of pre-slaughter.

Production performance of pigs reared in different systems and fed increased energy content diets with or without green alfalfa

“…Serum cortisol is widely used as an indicator of stress (Choe et al, 2014). In the present study, the levels of this hormone were similar and not differentiated among groups.…”

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

“…Therefore, the slaughter of pigs without rest or after short lairaging (15-60 minutes) is not recommended, because animals are exhausted and agitated (Vermeulen et al, 2015). The oxygen demand for aerobic glycogen depletion in acutely stressed pigs cannot be satisfied due to the decrease in blood supply to muscles, which contributes to higher production of lactic acid through the anaerobic metabolic pathway and elevates muscle temperature (+1 °C), consequently increasing the occurrence of PSE meat (Choe et al, 2015). The primary purpose of lairage is to help animals to recover from transport-associated stress, and it is expected to improve meat quality (Guàrdia et al, 2009).…”

Identifying Physiological Stress Biomarkers for Prediction of Pork Quality Variation

“…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]. Preslaughter stress influences body homeostasis and metabolism, resulting in alterations in the physiometabolic blood profile (electrolytes, hormones, metabolites, and enzymes), subsequently decreasing carcass and meat quality [7][8][9].…”

“…Stress metabolites, such as blood lactate and glucose, can be useful indicators for assessment of preslaughter stress, and their high blood levels indicate accelerated rate and greater extent of postmortem muscle metabolism, resulting in low muscle pH, while carcass temperature remains high, thus causing the higher prevalence of pale, soft, and exudative (PSE) pork [10,11]. It has been reported that adrenocorticotropic hormone (ACTH) [12] and cortisol [7] are useful indicators of the stress level experienced by pigs during the preslaughter period. 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]. However, some authors stated that the cortisol concentration had no impact on the pork quality [17].…”