How Many Eggs Can A Hen Lay?

The humble commercial hybrid hen has been bred to ensure peak egg production and yield consistency–but how many eggs a day does a hen lay a day, and how does the process happen? and you also need to know about which hens make the best layers, and which do not, along with why, and how to get the best eggs from your hens.

behind every egg lies some intricate biology; the story of a hen's laying cycle, and how its journey is influenced by breed, age, and environment.

We'll crack open (excuse the pun) the egg-citing lifecycle of laying hens, from the first eagerly anticipated egg to the sunset years of their laying career.

Compared to her fancy breed cousins and broilers bred entirely for meat production, the commercial layer carries little spare flesh and concentrates all her energy on producing an egg every day. In the past, all these ex-caged hens would be sent to slaughter at 18 months of age before changes in shell quality and decreased frequency of laying became apparent.

Between hatching and adulthood at 18 weeks, they are too young to produce eggs. From 0 to 8 weeks, they are in the Baby Chick stage, at 8 - 18 weeks (2 - 4.5 months), they are called Pullets (Growers). Once they start laying, the hens tend to be known as ‘Layers’.

What age do hens start laying eggs?

Most hens start laying eggs at around 18 weeks of age, but this does depend on the breed. Hybrid Hens (ISA Brown for example) start at 18 weeks whilst Pure Breeds, like Brahmas, may not start until they are 28 weeks old.

if your hen hasn’t gone into full retirement just yet. Therefore, you might also want to know how many eggs a day does a hen lay!

The laying process

Hens have only one functional ovary – the left one. The ovary contains follicles of differing sizes and maturity. When each follicle matures, it is called a yolk or vitellus. The yolk travels from the ovary into the oviduct.

The first part of the oviduct is the infundibulum, this is where the egg stays for roughly 15 minutes. If the hen has been mated this is where fertilization takes place. Beware! If you plan to breed from your girls it is important to know that sperm can survive in the oviduct for as long as four weeks.

The next part of the oviduct is the magnum where the egg remains for roughly three hours. The white is generated here. Passing down the oviduct the egg reaches the isthmus and remains for one hour while two membranes form around it.

Next comes a 24-hour period inside the uterus – the shell is formed at this stage. The final stage is the cloaca. With the help of the hormone arginine vasotocin, which induces uterine contractions, the egg is laid.

How many eggs a day does a hen lay?

how many eggs a day does a hen lay, and how?

You’d like to think this is an easy question – surely every hen pops out one egg a day? In theory, yes, but there are lots of factors which can affect egg production. So, just how many eggs a day does a hen lay?

A hen in her prime laying period between 20 weeks of age (point of lay) and 78 weeks of age would be expected to produce around 300 eggs annually. Within that time, she will also have periods of rest in her cycle when laying briefly stops. Happily, the majority of hens continue to lay after 78 weeks.

The humble hen egg is designed to be an ideal incubator and nursery for a growing chick embryo. The shell is porous – typically around 7,000 pores in the calcium carbonate shell allow air into the embryo. For this reason, it is not recommended that eggs be washed if floor-laid as bacteria can be introduced via this route. There are strict regulations governing egg production within the egg industry and eggs are not allowed to be sold as first quality if dirty or damaged in any way. Hens need 4g of calcium to produce one egg and if they are calcium deficient, this can affect their laying.

The hens we rehome have reached 18 months old, at which point their egg laying can slow down, especially if they go through a moult.

However, with a good diet, lots of regular sun and dust bathing, plus a bit of TLC, hens could lay up to three or four eggs per week.

What can affect a hen’s egg production?

As mentioned, a calcium deficiency is a major factor in a reduction of eggs. Then comes age, and the moulting process.

If your hen is sick or has been through any kind of trauma, this will also likely affect her egg laying for a short while. Rehomers often find that it takes a few days or even weeks after getting their hens home before they begin to lay – after all, it’s quite a process they go through.

Access to light is also a factor, and people often find their hens lay less during winter when daylight is shorter.

Finally, hens need a good quality, balanced diet in order to get the necessary nutrients for egg laying.

Why have my hens stopped laying?

1. Moulting – annually, most hens shed old feathers and grow new ones. This can take from a few weeks to perhaps 2 months. During this time, they will lay very few or no eggs as their energy goes into feather regrowth. It is a good idea to allow them to rest their bodies from the physical stress of egg production for a while.

2. Nutritional deficiencies - lack of essential nutrients, especially calcium. A balanced diet - see above - formulated especially for laying hens will give them everything they need. However, beware, too much carbohydrate and too many treats can make them fat, which will also stop them laying.

3. Lack of daylight - hens need around 14 - 16 hours of 'proper' daylight to produce an egg. Inevitably, this will fall off as days get shorter. Equally, if their coop and run area is dark and too shaded, they will stop laying.

4. Illness and parasites - this can affect their immune system and lead to infections that, in turn will reduce the hen's ability to lay eggs. A poorly hen will often stop laying while her body fights the infection. Parasites, especially worms, also adds stress to their system.

5. Stress - this can be a significant factor affecting their laying cycle. Changes to their environment like adding more hens to the flock, moving to a new coop, overcrowded coop, feather pecking, patrolling predators leading to shock, or frequent loud noises. All can lead their bodies to react to perceived threats.

Taking proactive steps to keep your hens happy and stress-free will maintain good egg production. Observation and good management are the key.