The incubation period of a chicken egg is 21 days. During this time, the egg is kept warm and humid in an incubator or under a brooding hen. The incubation period is the time it takes for the embryo inside the egg to develop and grow into a chick.
During the incubation period, the temperature and humidity levels need to be carefully controlled to ensure proper development of the embryo. If the temperature is too high or too low, or if the humidity levels are not optimal, the embryo may not develop properly or may not hatch at all.
On the 21st day of incubation, the chick will begin to "pip," or crack, the shell from the inside using its egg tooth, which is a small protuberance on the beak. After hatching, the chick will continue to rely on a heat source for several weeks until it is able to regulate its body temperature on its own.
Overall, the incubation period of a chicken egg is 21 days and is a crucial time for the development of the chick inside.