Abstract:
Chicken production is the first among Algerian poultry production. However, pre-slaughter
handlings were not standardized and changed according to technological, economic and religious factors. This leads to variability in animal’s welfare and the meat quality. In this context was the objective of our work, which focuses on the study of the effect of pre-slaughter conditions on the well-being of broilers and relations with the quality of meat in Algeria. Our approach consists of conducting a survey in eastern Algeria to highlight the different preslaughter conditions and techniques related to welfare of broiler chicken. In a second part, we have study
the effect of these conditions in the one hand on the welfare of animals by measurement of blood cortisol and glycaemia and on the other hand on the quality parameters of meat. We have used technological parameters that are pH, water drip losses, transformation yield and depth penetration in cooked meats and processed meats. In addition, we have study one-dimensional profiles of sarcoplasmic and myofibrillar proteins and identification of proteins subject of variation. Depending on the pre-slaughter conditions used in Algeria, we have identifi three modes that the broiler can be processed to reach the consumers. Direct artisanal slaughter on the ground at the time of sale or animals, they are bled at request of consumer without previous manipulations; industrial slaughter in killings were animals after collection and transport undergo a hanging on the slaughter chain upside down and are bled in this position. Lastly, industrial slaughtering in slaughterhouses with more handlings of animals because after collection and transport, animals are hunged upside down and then cross the electronarcosis tray to be bled at the end. Our results show that animals directly slaughtered were not stressed, while the others slaughtered after hanging, and those after hangings and electronarcosis were stressed, the latter two show no significant difference (p˂0.05) between them. Glucose and serum cortisol were positively correlated with pH30min, water drip losses at thawing and negatively correlated with penetration depths in cooked and processed meats. Glycogen phosphorylase, pyruvate kinase, creatine kinase and glyceraldehyde phosphate dehydrogenase present very high levels (p˂0.05) in extracts obtained from meats of stressed chickens. Glyceraldehyde-3-phosphate dehydrogenase and L-lactate dehydrogenase A wer positively correlated with stressed animals whereas they showed a negative correlation with troponin C and the light chain regulating myosin 2. Stressed animals had high values of serum glucose and cortisol. In addition, their meats have high values of pH30min, cooking and thawing drip loss, Glyceraldehyde-3-phosphate dehydrogenase and Llactate dehydrogenase A concentrations; their processed meat was less tender.
