Indicators of Pre-Slaughter Stress in Pigs and Their Impact on Meat Quality

Abstract

The pre-slaughter handling and transport of pigs can cause stress and negatively affect the quality of meat. This article aims to investigate the impact of pre-slaughter stress on meat quality. The literature suggests that pre-slaughter stress has a significant impact on meat quality, resulting in lower meat pH, increased drip loss, and decreased meat tenderness. When the body experiences stress, cortisol triggers the liver to release glucose into the bloodstream, which provides energy for the body to respond to the stressful situation. Both serum cortisol and blood glucose levels increased post-slaughter, with a post-slaughter mean value of 7.28 µg/dl for serum cortisol (compared to the initial mean value of 6.08 µg/dl), while the blood glucose values revealed a highly catabolic state, with mean post-slaughter values of 143.24 mg/dl compared to 129.11 mg/dl mean pre-slaughter results. The study highlights a direct relationship between increased serum cortisol levels and blood glucose values when comparing the pre-and post-slaughter values with the normal reference ranges, with a highly significant correlation between the mentioned parameters (p<0.01). The article also explores potential pre-slaughter indicators such as cortisol and blood glucose levels for predicting stress and meat quality in pigs. Improving pre-slaughter handling and reducing stress can lead to improved meat quality and economic benefits for the pork industry. In terms of pH24, a trust coefficient of 5.46–5.50 revealed the impact of pre-slaughter stress on meat pH, resulting in possible inferior meat in terms of quality. The study results showed a highly significant correlation between the cortisol and blood glucose values recorded post-slaughter and pH24 (p<0.05), emphasizing the impact of stress on meat quality and suggesting that both serum cortisol and blood glucose values can be used as specific indicators of meat pH and ultimately meat quality.