To candle an egg means to hold the egg up against a bright light in a dark room. People candle eggs to determine whether the embryo inside the egg is alive or whether the egg is infertile. It is important to candle the eggs to ensure that any eggs that isnt developing into embryos are not becoming rotten eggs that can contaminate the other eggs within the incubator.
If the rotten egg within the incubator can contaminate the other eggs, then the bacteria from the rotten egg can enter the healthy eggs, which will reduce the hatch rate of the healthy eggs from the incubator. There are several different types of eggs that can be identified through the candling process. A clear egg display no veins within the interior of the shell, and contains only the shadow of the egg’s yolk.
How to Candle Eggs and Remove Bad Eggs
A clear egg is typically an infertile egg. A blood ring is an egg that contains an embryo that has died within the eggshell. The blood vessels that contained the embryo has collapsed into a red circle within the egg.
A quitter egg is an egg that contains a dark mass within the interior of the shell, but the mass does not fill the shell. A rotten egg is an egg that is completely opaque to the light, and often has a sulfur smell to its interior as a result of the decomposition of its contents. Eggs should be candled according to a specific schedule.
At day seven of incubation, perform the first candle to check the eggs for the development of the embryo. At this stage, if the embryo is not visible within the egg, you can wait upon the egg until day ten to confirm that it is an infertile egg. On day fourteen of incubation, perform the second candle to determine if the embryos is still growing within the eggs.
Finally, perform a third candle shortly before lockdown to determine whether the embryo has completely filled the interior of the eggshell. When you identify bad eggs during the candling process, you should remove the bad eggs from the incubator according to a specific process. First, wear gloves when removing the bad eggs from the incubator, as the hands may introduce bacteria into the remaining eggs within the incubator.
Next, slowly lift the bad eggs from the incubator, and place the bad eggs into a sealed bag. Place the incubator back into its incubation mode after washing the area in which the bad eggs were located with a disinfectant, and allowing the area to dry. The schedule for candling eggs may change according to the species of the bird from which the eggs originate.
For instance, chicks that emerge from chickens eggs should be canded at day seven, day fourteen, and day eighteen. Ducks take longer to hatch from there eggs, so their eggs should be candled at a different schedule. The same process applies to quails eggs, except that because the incubation period for quail eggs is more short than that of chickens, you should candle the eggs earlier in the incubation process of the eggs, and with a fine light to focus on the eggs due to their smaller size.
Finally, the eggs of geese and turkeys have thicker shells than those of chickens. To aid in the viewing of the contents within these thick shells, you should use a brighter light when candling the eggs of geese and turkeys. Another process that can be performed after candling is known as the float test.
To perform a float test, place the eggs into a container with water. Healthy eggs that are incubating will tilt slightly upward when placed into the water. An egg that lies flat on the bottom of the container has an eggshell that is too fresh to be incubating.
An egg that bobs up to the surface of the water contains gas within its shell and should be discarded; however, you should not crack the egg near other eggs in the incubator. Importance is placed upon the process of candling eggs if it is to be performed consistantly. It is important to set a calendar reminder for each stage of candling to ensure that each stage is performed and that no eggs are incubated without being candled.
In the incubator room should be kept dark and the candling light should be kept focused on each eggshell. By candling eggs, eventually, individuals will begin to recognize the patterns of healthy eggs versus bad eggs. Additionally, the ability to recognize the unhealthy eggs will allow individuals to remove those eggs from the incubator prior to the unhealthy eggs ruining the incubator and its remaining healthy eggs.