The blood pO2 (Figure 4a and 4b) was significantly higher for the high-temperature group compared with the control group on ED 18 in the first experiment (during treatment, P = 0.0425; after treatment, P = 0.2465). In the second experiment (during treatment, P = 0.0013; after treatment, P < 0.0009) only at hatch, significantly increased blood pO2 was found for both temperature-manipulated groups compared with the control group.