The effects of a lowered ambient temperature on oxygen consumption and lung ventilation in the perinatal quail (Coturnix c. japonica).

The ambient temperature of embryos of pipped eggs and hatchings was reduced from 38 to 28 degrees C for a period of 1 hr. The weight-specific rate of oxygen consumption (VO2) of embryos and hatchlings at 38 degrees C was less than the predicted value for adults of the same weight. The Q10 value for mean weight-specific VO2 was 2.08 for pipped eggs, 0.98 for 4-hr-old hatchlings and 0.67 for 1-day-old chicks. The Q10 values for VO2 of individual embryos fell in the range 1.69-2.42, but the Q10 values for ventilatory frequency fell between 1.22 and 4.65. There was no correlation between the Q10 values for VO2 and ventilatory frequency for the same embryos. When ambient temperature was returned from 28 to 38 degrees C VO2 and ventilatory frequency returned to pre-cooling values within a period of 1 hr. The results are discussed in relation to the factors which influence gaseous exchange during the perinatal period.