CHAPTER 2:
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pr ot
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The incubation process
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You first need to understand how a single egg incubates and hatches before you can understand the incubation and hatching process at a hatchery. And even then, the step to using an incubator is a giant
py
one! That process is geared to the average egg and knowing that each batch contains a variation of eggs that must be taken into consideration. The greatest challenge is incubating and hatching all the
co
eggs in the most optimal conditions.
How is the embryo supplied with nutrients in the egg?
18
Period
Source for energy and development
Day 1 to 4
Carbohydrates from albumen and yolk as an energy source.
After day 4
Fats from the yolk (yolk is approx. 30% fat). Cholesterol and other components (fats) from the yolk create cell walls and nerves.
After day 12
Calcium from the shell for calcification of the bones. Protein for tissue formation is provided by the albumen. The energy needed is mainly provided by the yolk.
Weight changes in the egg during the incubation period
40 35 Weight proportion (%)
Unlike a mammal, the egg has to contain all the required nutrients from the moment of oviposition. The shell around the eggs allows the exchange of heat, gases and moisture. The gas exchange depends on external factors. During the incubation process, you will notice changes in the utilisation of nutrients and in the development of the different parts of the embryo.
albumen
30 25
embryo
yolk
20 sub-embryonic fluid
15 10
allantoic fluid
0 0
0
5
amniotic fluid
10 15 Incubation time (days)
20
Changes that occur in the mass of the embryo, yolk and the albumen (egg white), and in the volume of the fluid structures of the developing embryo. Ha tc he ry S i gnal s
