QUALITY OF PORK MEAT, DEPENDING ON THE CONDITIONS OF PRE-SLAUGHTER HANDLING
Abstract
The aim of this study was to investigate the relationship between the duration of pre-slaughter time and the quality of the pork meat obtained. The material for the research was the blood and meat of pigs of industrial and domestic origin. Twelve groups of pigs were formed with different combinations of weaning time and stay at the meat processing plant before slaughter. Blood cortisol and lactate levels, pH and meat quality were assessed. The quality of pork depends on the severity and duration of stress experienced by the animal before slaughter. The highest levels of cortisol were found in the blood plasma of industrially raised and slaughtered pigs that were weaned 22-24 hours before slaughter, and the lowest concentrations were observed in pigs raised and slaughtered on small farms. The highest levels of lactate were found in the blood of pigs that were weaned 6-8 and 10-12 hours before slaughter, 1-1.5 hours of which animals were at the meat processing plant. In the meat of pigs with high levels of lactate in the blood, a shift of pH to the acidic side was recorded, followed by a gradual decrease of the level during maturation. Despite the lower levels of lactate in the blood of pigs, after 22-24 hours of fasting, the pH of the meat was more acidic, which decreased slightly during 12 hours of maturation. Under these conditions, a significant number of samples of the longest back muscle were of poor quality. The main reasons for the negative impact are the use of muscle carbohydrates under prolonged stress, clogging of muscle fibers with production of exudate, resulting in dry, hard and dark meat. Despite the lower level of stress markers in domestic pigs, a significant number of meat samples were also of poor quality, due to poor carcass bleeding. The optimal conditions for pre-slaughter keeping pigs are their weaning 10-12 hours before slaughter, 3-4 of which they will spend at the meat processing plant. Under such conditions, the highest quality meat is achieved. Increasing of the duration of the period of starvation, as well as reducing or prolonging the stay of animals at the meat processing plants can negatively affect the quality of meat due to the increasing impact of stress factor. In case of slaughter of pigs in small homesteads, it is recommended to carry out fasting before slaughter for 10-12 hours.
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