Indicators of Physiological Stress in Broiler Chickens During Road Transportation

Abstract Differential leucocyte counts and plasma activities of the muscle enzyme, creatine kinase, have been determined in blood samples obtained from broiler chickens, immediately prior to and following road transportation from farm to processing plant for slaughter. These parameters are proposed as indicators of physiological stress based on previous findings. Heterophil:lymphocyte ratios and plasma creatine kinase activities increased and eosinophil counts were decreased during the journey in birds tranported in both July and October when the curtain sides of the vehicles were open or closed respectively. These findings are consistent with the presence of physiological stress during road transportation. The thermal microenvironments to which birds are exposed in transit are thought to represent one of the sources of this ‘transportation stress’.