Candling are the process of holding the egg up to a bright light in a dark room in order to view the contents of the egg. Candling is a necessary step in the incubation processes due to the fact that candling allow for individuals to view if there is an embryo developing inside of the egg. By candling the egg, individuals can determine whether the eggs is fertile or if the eggs are infertile.
Thus, candling allows individuals to determine which egg will develop into chicks, and which eggs will not. When viewed through a bright light in a dark room, the contents of the eggs will appear uniform during the first few day of incubation. However, around the third day of incubation, the candler will see the blood vessel that supply the embryo with the nutrients that it needs.
How to Candle Eggs and Check Their Development
Around the fourth day of incubation, the heart of the embryo will become visible inside the egg. People can see these developing embryo in order to remove the infertile eggs from the incubator. By removing the infertile eggs from the incubator, the incubator can be kept clean, and the growth of bacteria can be prevented.
During the middle portion of incubation, the embryo will become larger and the blood vessel will become more densly within the egg. In addition, the dark shape of the embryo will fill more of the egg. The air cell, which contains the oxygen that the embryo needs in order to develop, will become more prominent in size during this period.
By monitoring the air cell, individuals can ensure that the moisture level within the incubator are appropriate. Should the air cell not become larger during incubation, the incubator is likely too humid for the chicks comfort. Should the air cell become more too large during incubation, the humidity within the incubator is likely too low.
At eighteen days of incubation, the embryo should of rotated within the egg so that the head of the embryo is resting against the air cell. At this stage, the egg will appear mostly dark with the embryo throughout the majority of the egg. At this point, the eggs should no longer be turn.
If the eggs are continued to be turn, the embryo may get disoriented. During this stage, the humidity should be increased for the same reasons as those of day eighteen: to prevent the membrane from adhering to the embryo. Candling can help to identify if the embryo has failed to develop proper within the egg.
If viewed through a bright light in the dark room, unfertilized eggs will appear clear. If the embryo dies during the first few days of incubation, a blood ring will appear around the egg. Any embryo that does not move after day fourteen of incubation is referred to as a “quitter.” Both murky and cloudy egg are considered to be rotten eggs.
These types of egg should be removed from incubation immediately in order to prevent the spread of bacteria to the other eggs in the incubator tray. In order to assist the embryo to hatch from the egg, individuals must exhibit patience. The chicks require time to absorb the yolk containing the nutrients that they need in order to survive after hatch day.
Additionally, the chicks need time to develop the neck muscle that are necessary to perform the hatching process. Most healthy chicks will hatch from their egg on their own within twenty-four hour after they begin to pip. To provide information regarding the development of the embryo within the eggs, there are three main checkpoints at which the eggs should be candled.
At day seven of incubation, the eggs should be candled to determine if they are fertile. Between day fourteen and fourteen, the eggs should be candled to remove any that has ceased developing. On day eighteen, the chicks should be candled to ensure that they are in the proper position within their shells prior to the lockdown period of the incubator.
The eggs should not be candled between these time period as the embryos should remain undisturbed within the eggs. By candling the eggs, information can be provided regarding the effect of the incubator and the climate on the development of the embryo. With enough incubation cycles, individuals will begin to notice difference in the development rates of chicks from different laying hens, or the difference in humidity throughout different seasons.
By becoming familiar with the normal development of the embryo, an incubator can be fine-tuned to provide the most effective incubation for those eggs.