When examining the lung fields of a normal CXR, the outline (silhouette) of the heart borders; the ascending and descending aorta; the aortic knuckle and the hemidiaphragms should be clearly visible. 1  All of these silhouettes, or structures, are in contact with a specific portion of the lung.
Perhaps the most important parameter is temperature â chicken eggs should be incubated at a temperature between 99 and 102 degrees Fahrenheit (99.5 is often considered to be ideal) and 50 to 65 percent relative humidity (60 percent is often considered the ideal).uring the final three days of incubation, the eggs should ideally be located in a slightly cooler (98.5 degrees) and more humid (65 percent relative humidity or greater) environment to facilitate successful hatching.
Hormonal changes accompany the onset of incubation, with levels of prolactin in the bloodstream increasing and levels of testosterone falling. The ideal temperature for most species to incubate their eggs is c. 38Â°C and this is achieved by developing a highly vascularised brood patch where heat from the body warms the eggs.