Upper lethal environmental temperature in turkeys

The investigation employed an observational approach following an accidental equipment failure in a research facility. Sixteen turkeys were housed within a climate-controlled chamber featuring low air circulation. Prior to the incident, the subjects resided at a stable 20 degrees Celsius for six days. The researchers performed post-exposure assessments on the two surviving birds. Their protocol involved collecting blood samples to evaluate hematological parameters and endocrine markers. Histological examination of the bursa of Fabricius provided insights into cellular immune changes. The team compared the physiological status of an alert survivor against a depressed survivor. This review approach synthesized data gathered immediately following the 16-hour heat stress event.

The primary finding indicates that 14 out of 16 turkeys perished during the 16-hour exposure to 38.5 degrees Celsius. The survivors exhibited a marked increase in plasma corticosterone concentration compared to baseline expectations. Hematological analysis revealed an increased percentage of erythrocytes within the hematocrit for both survivors. The researchers documented a decreased ratio of blood mononuclear cells to polymorphonuclear cells. Histological inspection showed a definite reduction of lymphocytes in the bursal follicles of the alert bird. The depressed survivor displayed a nearly complete depletion of these same lymphoid cells. These results confirm that extreme thermal conditions induce systemic physiological failure in domestic turkeys. The data quantify the severe impact of high humidity and heat on avian survival.

The authors propose that prolonged heat exposure triggers significant physiological distress in domestic birds. Their synthesis suggests that elevated corticosterone levels serve as a primary indicator of severe thermal strain. The findings imply that hematological shifts, such as increased erythrocyte percentages, occur alongside immune cell ratio alterations. The researchers highlight that bursal follicle depletion serves as a marker for extreme environmental stress. These observations suggest that survival outcomes vary significantly between individual birds under identical conditions. The study implies that thermostat malfunctions represent a severe threat to poultry welfare in controlled environments. The authors conclude that high humidity levels accelerate the lethal impact of elevated temperatures. These results provide a baseline for understanding the physiological costs of heat-related environmental accidents.