Model of physiological stress in chickens 3. Temporal patterns of response

The temporal pattern of stress responses following continuous infusion of adrenocorticotropic hormone (ACTH; 8 IU/kg BW/d for 7 d) in broilers was determined in two experiments. Results indicate that the order of responses were elevated plasma corticosterone (CS) by 2 h, elevated plasma glucose (GLU) by 12 h, increased liver weight concomitant with increased hepatic lipid and decreased liver moisture by 18 h, decreased relative weight of the spleen by 24 h, elevated heterophil/lymphocyte (H/L) ratio by 2 d, decreased body weight and relative weights of the bursa of Fabricius and thymus by Day 4, and decreased liver soluble protein content by 12 d.