Hen eggs in 10 questions and answers

How can hens lay eggs without a cockerel?

Indeed, a hen lays regularly even without a cockerel. Quite simply, this is because an egg is a mature ovum, and a hen ovulates practically every day. All these ova are stored in an ovarian follicle until they mature. These clusters of ova form a kind of string that actually represents all of a hen’s future eggs. The follicle then releases the mature ovum, which travels to the uterus via the oviduct. When one string is used up, another forms, marking the beginning of a new laying cycle. It generally takes around twenty days for this new string to form, during which time your hens stop laying.

A hen ovulates daily and does not need a cockerel to lay eggs. However, a cockerel is useful for fertilising them

Each egg consists of a yolk, white and shell. The yolk is the amniotic egg, while the white is albumen secreted by the oviduct, which protects the yolk. Finally, the shell, consisting mainly of calcium crystals, forms over about fifteen hours and protects the egg.

Unlike other birds, hens can ovulate practically all year round. Quite simply, this is because they have been domesticated for thousands of years, cross-bred and artificially selected… Originally, however, a hen, like other birds, only produced ova (laid eggs) at specific times.

How can you tell whether an egg is fertilised?

An egg can only be fertilised if your hens cross paths with a cockerel. And even then, they need to mate! But believe me, cockerels are more than capable of servicing several hens! What is more, with each mating, virtually all the ova that make up the chain and are stored in the follicle are fertilised. Thus, a cockerel in the prime of its life can fertilise up to 80% of the ova. Then, with each laying, the hen releases her fertilised (or unfertilised) eggs and incubates them. This explains why the chicks do not all hatch on the same day…

Theoretically, all a hen’s eggs can be fertilised once mating has taken place. However, an embryo only develops in one (over 21 days) if the egg is incubated. This means that an egg collected each day may be fertilised, but can still be eaten.

Once the hen starts incubating, the embryos may develop.

You need to candle the eggs incubated by a hen to find out whether they are fertilised

But sometimes not all the eggs are viable. How can you tell whether an egg is truly fertilised or not? You need to candle it, in other words, hold it up to the light, using a strong light source. Hold the egg in your hand and place the light source beneath the rounded end. This allows you to see what is happening beneath the shell:

• if the egg is completely transparent, it is not fertilised (or has only just been laid)
• if the egg is striate with red veins, it is fertilised
• if the egg appears dark and you can make out a shape, it is not only fertilised, but a chick is developing inside it.

Why are hens' eggs different colours?

The colour of a hen’s eggs does not depend on its diet or state of health, but solely on its breed. The range of colours is relatively broad, from lighter to darker shades, depending on each hen’s genetic make-up. As for the colour of the shell, this is determined by pigments derived from the blood or bile of your hens.

From pure white to chocolate brown, eggs vary in colour according to the hen’s breed

So, if you want to collect eggs in different shades, keep hens of different breeds. Let’s open the colour chart:

• Marans hens lay dark brown to brown eggs, almost chocolate-coloured
• Leghorn and Gatinaise hens lay perfectly white eggs
• Araucana, Ameraucana, Javanese and Cream Legbar hens lay eggs whose colour ranges from green to pale blue
• Barnevelder and Welsummer hens lay reddish-brown eggs

Other hens, such as the Rhode Island Red, Orpington, Vorwerk and Sussex… are content to produce light brown eggs.

→ You may also like our advice sheet: Why do hen eggs come in different colours?

How many eggs does a hen lay per day? Per year?

The answer to the first question is simple (although…), while the answer to the second is a little more unpredictable. Generally speaking, a hen lays one egg a day but, occasionally, it may lay two in a day, or more precisely two in a 24-hour cycle, bearing in mind that it takes between 15 and 26 hours for the egg to form.

On the other hand, determining the number of eggs laid in a year is more complicated, as it varies according to the hen’s breed, age and the season. Certain breeds, such as the red hen, Sussex, Gatinaise, Vorwerk, Marans and Harco, are champions in every category, laying between 200 and 300 eggs a year. This figure can vary depending on the food and comfort provided. You should also know that hens lay fewer eggs in winter because of the lack of daylight and the cold. Summer heat can also affect them.

Red hens, Sussex, Gatinaise, Vorwerk, Harco and Marans are among the most prolific egg-laying hens

For how many years does a hen lay eggs?

Once again, the length of time a hen lays eggs varies according to several factors, including its breed, diet and living conditions… Generally speaking, a hen lays prolifically until it is 3 years old. After that, egg production declines by around 20% per year. Most hens stop laying altogether at around 8 years old.

Why do hens sometimes lay eggs without shells?

Several reasons can explain the laying of a shell-less egg, which is completely soft. It can start with a young pullet beginning to lay. These first eggs often have a very thin shell, or none at all.

A hen suffering from calcium deficiency may also lay shell-less eggs, essentially formed of calcium crystals. To remedy this problem, it is recommended that you provide your hens with crushed oyster shells or their own ground eggshells (with the risk that they may eat their eggs!).

Finally, the laying of shell-less eggs may also be explained by a period of stress caused by a predator attack, poor hygiene, moulting or excessive heat.

How to store your eggs?

This is a question that has always caused disagreements between those who favour the fridge and those who do not. Generally speaking, it is recommended that eggs be kept at room temperature, up to 22 °C only. This is, after all, how they are stored in supermarkets. However, there is no reason not to keep them in the fridge. Ultimately, it is fluctuations in temperature that are more likely to encourage the proliferation of bacteria such as salmonella.

Whether kept outside or in the fridge, eggs must not be exposed to fluctuations in temperature

You can therefore keep your eggs in a garage, cellar or unheated conservatory, but avoid the kitchen worktop, where temperature changes are quite significant. As soon as the summer heat arrives, put them in the fridge or in a room that remains at least reasonably cool.

How long can eggs be kept?

Eggs keep for 30 to 40 days if they are stored in suitable conditions. We strongly recommend writing the laying date in pencil on each freshly collected egg.

If it is slightly cracked or broken, it must be eaten within 2 days at most.

How can you tell whether an egg is fresh?

Haven’t you written the laying date on your egg and are wondering whether to eat it? A simple trick is to place it raw in a bowl of cold water. If it sinks to the bottom, it is very fresh. If it stays in the middle, it is safe to eat as an omelette or hard-boiled. However, if it floats at the surface of the water, it is best to throw it away.

Can eggs soiled with soil or droppings be washed?

Above all, do not wash eggs soiled with earth or droppings. Why? Washing them makes them porous because it removes the fine protective layer that surrounds them. This makes it easier for bacteria to get inside. The only time you can clean them is just before cracking them.

An egg should only be washed when it is about to be cracked