American Small Farm & Country Life Magazine > FREE-RANGE POULTRY

Hatching Chicken Eggs - Selecting, Setting & Candling


Tasty Chicks:
Thanks,thats very informative

Fely-S E Asia

Hatching Chicken Eggs - Selecting, Setting & Candling

It's time to set your eggs!

In 21 days or so, you'll have chicks!

Prepare your incubator by heating it to the manufacturer's recommended temperature and a relative humidity of 58 to 60%. Adjust the vents if necessary.

You've been storing eggs selected for this purpose. It's time to select the freshest, best eggs to set. Because you've been marking the date you collected the eggs with pencil, selecting the freshest eggs is obvious. Remember to select medium sized eggs, with no cracks, that are uniform in shape.

Allow the eggs to come to room temperature. You've been storing them at a temperature of 55 degrees F. If you place eggs directly from storage into the incubator with a temperature of 99-102 degrees F, you will cause condensation. Because the egg shell is porous, some of this moisture will be absorbed by the egg, which is not okay.

Your goal is to handle the eggs as little as possible. Each time the eggs are handled, some of the protective bloom, or coating is worn away. Make sure your hands are always clean and dry before you touch the eggs.

Some incubators automatically turn the eggs.  If you will be turning the eggs yourself, it is helpful to make a mark, in pencil only, on the side of the egg. If you've marked the date collected on one side, you could put another mark opposite it on the back. You could also use an X and O. These marks are important to make sure you are turning the eggs completely. We'll address turning eggs more thoroughly in a moment.

Once the eggs have come to room temperature, carefully place them in the incubator.

Models vary so your eggs may lie horizontally with one end slightly elevated or be placed vertically. Either way, the larger, round end of the egg should be up. This is the part of the egg in which the chick develops. Try to space the eggs evenly allowing room for turning. Eggs may not touch the sides of the incubator and not be too close to the heating element as this will cause uneven heating, leading to a poor hatch.

Once the eggs are in place, close the incubator and wait for the temperature and humidity to stabilize. Because you have added the eggs causing the interior environment to change, you will probably need to adjust the temperature and humidity. This is where the skills that you learned last week in making minor adjustments comes in handy.

If you set the eggs in the morning, count this as day 1, if you set the eggs late in the day or in the evening, count this as day 0 and tomorrow as day 1.

In either case, once you have set the eggs, do not touch them for the first day.

The developing chicks are most delicate at the beginning and the end of the incubation period.

Beginning on day 2, you must turn the eggs 3 to 5 times each day. Try to keep regular, frequent intervals. Turn the eggs either or way round each time.

Turning of the eggs is crucial because the chick will stick to the surrounding membrane if it stays in the same position too long. Always turn the eggs an odd number of times each day. In this way you'll ensure the eggs will be on opposite sides for the long night rather than resting in the same position.

You may want to make a check sheet to mark off each time you turn to help you keep track. Obviously this is a personal preference but for someone like me who often doesn't remember what I served for breakfast, a tool like this is helpful.

Ventilation is important.

The developing chick requires oxygen which passes right through the porous shell and in turn it gives off carbon dioxide in the same manner. Follow the instructions included with your unit to maintain proper ventilation making sure the ventilation holes are never obstructed. Also remember that the room in which the incubator is located must have a good supply of fresh air.

There is no way to tell if an egg is fertile when it is laid without cracking it open.

However, you need to see if the eggs you are incubating are fertile, otherwise they will not hatch. An infertile egg will also give off harmful gasses as it rots, it will use valuable oxygen and could explode, layering all the other eggs with bacteria-laden goop.

You can tell if an egg is fertile by "candling" it. Candling is simply shining a light through the egg in a dark room to illuminate the interior of the egg. In this way, you can see if a chick is developing inside or not.

You can candle your eggs anytime between day 5 and day 17.

Only candle 5-7 eggs at a time and make sure they are out of the incubator only five to ten minutes.

There are candling boxes available for purchase but you can easily make your own.

One way is to cut a hole, smaller in diameter than the egg, in the bottom of a coffee can. You'll want the egg to sit securely but have the majority of the large end exposed. Place the coffee can over a 40 watt light bulb. Another easy way is to use a toilet paper tube if you can find a flashlight that will fit inside one end. Place the egg, LARGE END UP ALWAYS, on top of the other end of the tube. Get creative making your own candling devise. The goal is to concentrate a source of light through the egg.

If the light shines through the egg in a uniform manner, meaning the egg is clear, that egg is infertile and should be removed from the incubator. You should see a mass and spider like veins early on in the incubation process if the egg is fertile. If the egg is clear after 7 days, it is not fertile or the chick has died. Later on in the process, the whole interior of the egg will be dark except for the very top of the large end of the egg.

It is much easier to determine the contents of white or light colored eggs than brown eggs. You'll need to wait until later in the incubation to candle brown eggs when the chick is more defined. Molted eggs are very difficult to candle. If there is question as to whether the egg is fertile or not, wait a few days and try again.

You will also notice as you are candling that there is an air cell at the top of the egg.

You may remember from a previous issue that inside the shell is a thin membrane, inside that is another membrane encasing the whites or albumen of the egg. As evaporation takes place, an air cell is created between these two membranes. It is because of the increase in size of this air cell that a "float test" determines whether an egg is fresh or not.

Ultimately, the air in this space will be the first air your hatching chick will breathe. Because of evaporation, the weight of the egg should decrease by 12% from the time it is laid to just before hatching if a good hatch can be expected.

Control the rate of evaporation by controlling the humidity within the incubator. The speed at which the air cell grows determines whether the percentage of relative humidity is appropriate for your particular environment. For now, stick with the recommended percentages of humidity above. While you are candling though, take notice of the air cell within your eggs so that you can make adjustments to the relative humidity in future settings.

For more resources visit the Back 40 Books Range Poultry Production Department by clicking the image below:


[0] Message Index

Go to full version