Cardiovascular Changes in Restrained Chickens

EVIDENCE was presented by Sturkie and Newman (1951) that the handling of unanesthetized chickens coincident with blood sampling resulted in an increase in plasma volume and a reduction in the percentage of red cells in the blood. It was suggested that these changes might be due to the release of cortical hormones from the adrenal glands in response to the stress imposed by restraint. Recent work has supported the belief that handling and immobilization are stressful conditions to chickens, being associated with an increased rate of secretion of adrenocortical hormones (Newcomer, 1958; Wolford and Ringer, 1962). The purpose of the experiments described in this paper was to find out if changes occurred in the rectal temperature, respiratory rate, cardiac output, blood pressure, heart rate, arterial hematocrit and total peripheral resistance of chickens that were not subjected to any experimental procedures other than those required to make the measurements. Experiments…