Abstract: | Metabolic responses of unrestrained White Pekin ducks, Anas platyrhynchos, were determined at ambient temperatures of -5 degrees, 1 degrees, 10 degrees, 20 degrees, and 30 degrees C. Temperatures from the pectoralis and the subcutaneous back were monitored. Unrestrained ducks exhibited two metabolic states, a high response (540 cc. O2/kg/hr. at 20 degrees C.) and a low response (427 cc. O2/kg./hr. at 20 degrees C). Pectoralis muscle temperature did not vary greatly over the range of ambient temperatures tested and was considered to be a good representative of body temperature. |