Effect of exercise on the cardiovascular and respiratory systems of heavy turkeys and relevance to sudden death syndrome.
The cardiorespiratory response to walking exercise was studied in 14-to-18-week-old male and female heavy turkeys. Blood pressure, electrocardiograms, respiratory rate, body temperature, blood gases, and electrolytes were measured at rest and after exercise at two different room temperatures. After exercise, systolic, diastolic, and mean blood pressures decreased, and heart rate and body temperature increased, while a severe lactic acidosis developed, in both sexes and at both room temperatures. Fifty-four percent of the turkeys developed arrhythmias, mostly a transient post-exercise sinus arrhythmia of no clinical significance. Changes in electrolytes were clinically insignificant. Blood gases remained within normal limits, demonstrating adequate gas-exchange and pulmonary capability. Within the limits of this study, the cardiac capacity of the heavy turkey in response to exercise appeared very limited. The pathogenesis of sudden death syndrome of turkeys is still unknown, but cardiovascular changes occurring after exercise could be severe enough to cause death.