1. 1.|Oxygen consumption and organ growth were measured in domestic-fowl embryos incubated at different temperatures (36, 38 and 40°C).
2. 2.|Embryonic oxygen consumption was highest at an incubation temperature of 40°C and lowest at 36°C. These differences were ascribed largely to variations in embryo size at different incubation temperatures.
3. 3.|At incubation temperatuers of 40 and 38°C, there was a plateau in oxygen consumption late in incubation, but this was not apparent at 36°C.
4. 4.|At 36°C, some tissues (e.g. eyeballs) were “spared” the repression of growth that characterized the embryo as a whole, while other tissues (e.g. stomach) incurred a much greater growth reduction. Similarly, at 40°C, stomach growth exceeded that of the embryo as a whole, while the eyeballs were largely spared the enhanced growth.
5. 5.|A simple index of tissue age revealed that, in general, there were consensual changes in tissue maturity and growth at different temperatures but that there were some disparities between growth and maturity in individual organs.
Author Keywords: Avian embryos; temperature; organ growth; oxygen consumption; Gallus domesticus
