Egg Fertility Basics

Most people don’t realise that you need fertile eggs to hatch a chick.

Eggs are laid by female chickens. You need a rooster (male chicken) with your hens to be able to hatch your own eggs. And to ensure you have a high fertility rate, it is best to have one rooster for every 3-8 hens. The best ratio I have found is having 2 roosters covering ten to twelve hens.

Diet is also important. You need to ensure that your flock has a well balanced diet and has plenty of water. Any stress to your chickens will result in poor quality eggs and low fertility rates. Regular layer pellets provide a good balanced diet. But chickens LOVE scraps and fresh leaves. So anything from your table that you don’t eat (this includes small cuts of meat too) are perfect for chickens. Any weeds you pull from your garden are also excellent supplements for your flock, especially all the slugs and snails!

Chickens do not lay eggs all year round. They have a “break” over the winter months and stop laying daily. When daylight hours start to lengthen (after June 22nd in the Southern Hemisphere), chickens begin to lay more eggs again. The last month of winter is considered by most to be the start of the breeding season for chickens. The eggs laid during the last month of Winter and through Spring are the best used for hatching.

Here is an image of some of our Plymouth Rock flock chowing down on some scattered feed and fresh leaves.

Checking Fertility

A fertile egg is one that has a sperm bundle with it. If you grow your own chickens and use their eggs, you will notice this as an extra yellowish bundle attached to the egg yolk when it is cracked open.

You cannot check for fertility immediately after laying. This is especially true for eggs that have a thick shell or dark colour. The best time to check for fertility is around 5 days after incubating starts. This is done using a technique called candling. Essentially, you shine a bright light through an egg to determine if the embryo has started to develop. A developing embryo is one where you can clearly identify blood vessels traversing through the egg white from the embryo (egg yolk). Any egg that is not fertile needs to be discarded. Nothing smells worse than a rotten egg exploding in an incubator. Blech!

Collecting eggs for incubation

Eggs that you collect for incubating need to be treated a little differently to those you use in the kitchen. Here is a list of pointers…

Check out our other post about incubation for more info on hatching your own chicks.