Day 1: The Journey Begins
Incubation
The age of the embryo when the egg is laid
varies. Hens tend to lay eggs during the middle
of the day; if the egg is not complete until later
in the day, it will probably not be laid until the
next day. The rate of development of the embryo
once the egg is laid also varies. If the eggs are
cooled after laying, development of the embryo
ceases until the temperature rises again.
Development can resume even after the eggs have
been cooled for several days. The temperature of
eggs incubated by their mothers is 106 degrees
Fahrenheit (the average body temperature of a
hen). The temperature of course will vary when
the hen leaves the eggs to eat, etc. All of this
affects the rate at which the embryo develops and,
therefore, how long it takes for the chick to
hatch. Artificially incubated eggs are kept at a
constant temperature of 99 to 100 degrees F. At
this temperature the eggs will hatch in 21
days.
Text and graphic by Janet Sinn-Hanlon
- Page 12 of 12 -
|