CANDLING EGGS

By Trish Dillinger
Fowlerville, Michigan
Copyright © 1990 NCS
(All Rights Reserved)

Copyright Notice & Disclaimer Statement

There are times when most aviculturists, for one reason or another, wish to candle some of their eggs. In fact, candling is a serious business for those in the poultry industry who hold candling competition in egg shows throughout the country. Their interest is in the factors that affect egg quality where ours is mainly to see if the egg is fertile.

A hurricane lamp with a clay pot set on top makes a simple but effective way to candle eggs. Light shines through the egg to make the entire inner contents almost as visible as if there were no shell. It not only lets the breeder know if the egg is fertile, but if an egg is not discovered for a few days, the age can be determined by the size of the air cell, giving a better estimate of hatch date. Halfway through the incubation you can actually see the chick actively moving within the shell. A fifty watt bulb is the minimum used, but care should be taken not to use wattage so high as to overheat the chick. One thing I would like to add is that the germ of a fertile egg begins to develop at about 69°F. Under favorable conditions, an egg can be stored for a few weeks and fostered with success.

I recently experienced this when my whiteface hen laid an egg in the flight. I didn't have any pairs set up at the time, so I put the egg in a half filled seed cup, with the small end up, so the air cell would not dry out, (eggs do not have to be turned this way) and set it on the counter. In the next few days, I set up a pair of lutinos. After the hen laid her second egg, I added the foster egg. The time between when the egg was laid and fostered was about three weeks. When the eggs began to hatch, the second to pip was a healthy whiteface chick.

NOTE FROM LESLIE HUEGERICH OF K & L AVIARY:  I use a small penlight or a Mini mag flashlight to candle eggs. I keep this in the breeding room at all times so I know where to find it. I place the eggs (from one pair at a time) in a bowl I've lined with tissues. I then take them into a dark room, turn the lights off, turn the penlight on, pick up one egg at a time and hold it to the flashlight. You may have to move the flashlight around the egg. I've had the best luck candling the egg from the top (where the air sack is). If the egg is fertile (check it about 7 or 8 days after it was laid and this should be obvious) it will have a network of real tiny red veins that look almost like a spider web inside the egg. If this is seen, the eggs are fertile. After checking the eggs, replace them in the nest.

Handle eggs ONLY with clean, warm, dry hands. If you don't wash your hands before handling the eggs, you can possibly spread bacteria to the chick through the egg.

If there is no "web", place the egg back in the nest for another few days and check it again. I don't recommend throwing out infertile eggs. The reason I say this is because after laying eggs the hen needs to rest and build up her calcium levels before laying more. If you remove one or more, she may feel a need to replace it with another egg which can deplete her calcium reserves very quickly.

[ Home ] [ NCS - Avian Diseases Libary ] [ NCS - Behavior Libary ] [ Breeding Libary ] [ Healthcare Libary ] [ Cockatiel Clinic ] [ Color Mutations ] [ Nutrition Libary ]