Developmental patterns of O-2 consumption, heart rate and O-2 pulse in unturned eggs

The effects of failure to turn eggs on the developmental patterns of oxygen consumption (M(O2)), heart rate (fH) and O-2 pulse during the second half of incubation of individual chicken eggs were examined. The M(O2) of unturned eggs increased at a significantly lower rate than the control toward the end of prenatal incubation, and the plateau M(O2) between day 17 and 19 was significantly lower than the control. Lack of turning also resulted in significant changes in the developmental patterns of fH and O-2 pulse. It is suggested that the effects of lack of egg-turning on the developmental patterns of M(O2) may be attributable to lower embryonic growth rate in addition to impairment of gas exchange through the chorioallantoic gas exchanger.