A variety of things can reduce laying, but if you start noticing the change sometime between mid-September and December, one of the most likely suspects is the shortening of daylight hours that occurs this time of year.
Why does the number of daylight hours affect laying?
Laying hens are very sensitive to day length. Most resources say that hens need 14-16 hours of daylight to lay their best.
Without getting into a lot of technical details, the hen’s endocrine system, and in particular her hypothalamus, working in conjunction with her pituitary gland, regulates the release of certain hormones that affect growth, molting and reproduction (or, for purposes of this discussion, egg laying).
Now a brief science lesson, then we’ll get back to chickens and egg laying.
Latitude and Day Length
In the northern hemisphere, June 21 is the day with the most daylight hours, and December 21 is the day with the least. (These dates are called the “summer solstice” and the “winter solstice,” respectively.)
Your latitude affects how much the day length varies. (Latitude is the angular measure of how far you live from the equator, and it’s measured in degrees.) The further you are from the equator, the more the day length varies. On or near the equator, every day of the year has about 12 hours of daylight, from sunrise to sunset (plus about 1/2 hour on either end to account for dawn and dusk, when the sun is down but it’s light out).
Southern states range from 25° to 36°N latitude. Northern states in the continental U.S. reach 48°N latitude, and Alaska reaches 71° N. This tool will show the latitude where you live and anywhere else by clicking on a map.
If you’d like to explore the number daylight hours where you live, first find your latitude, then use the daylight hours explorer application to see how many hours of daylight there are between sunrise and sunset for your latitude for any particular day of the year. (As mentioned above, it will get light about 1/2 hour before sunrise and stay light about 1/2 hour after sunset, so I would add about an hour to the numbers shown by this tool.)
So, throughout Texas and the continental U.S., there will be months when you receive fewer than the 14 hours of daylight recommended for optimal laying. This means you’ll likely have times, between September/October and December, when your chickens slow down their laying and even stop simply because they don’t get enough hours of daylight to stimulate laying.
Artificial Lighting
If you want to, you can extend the number of “perceived daylight hours” by putting a light on a timer in your chicken coop. For most home flocks, a 40W bulb should be sufficient.
It’s best to set the bulb to come on in the morning before sunrise rather than at night. The reason is that in the evening chickens need time to find their spots on the roost. The gradual darkening of the sun setting naturally provides for this. If you use an artificial light that goes off rapidly, your chickens will find it harder to get settled. A light that’s set to come on before dawn avoids this problem.
If you’ve waited to start using artificial lights until after the days have already gotten short and your chickens have already stopped laying, it’s best to give them some time to adjust. Start by setting the light timer about 1/2 hour before sunrise, then gradually set it earlier until you reach the point at which they’re getting 14-15 hours of light.
Precaution #1: If you use artificial lighting, please be careful not to create a fire hazard. With wooden coops and straw or wood shavings for bedding, it’s important to make sure the hot light bulb can’t touch or get too close to anything that’s flammable. Plus there’s usually water in or around chicken coops, which you don’t want coming in contact with your electrical connections or the light bulb or fixture.
Precaution #2: Don’t use “shatter resistant bulbs”. These bulbs are coated with a clear plastic coating. When that coating heats up, it produces fumes that can kill your chickens. Several years ago, I learned of this account in which someone lost an entire coop of chickens because of fumes produced by use of a shatter resistant heat lamp bulb in a coop, so please avoid that.
Precaution #3: If you have pullets that have not yet started laying, it’s not a good idea to use artificial lighting to create artificially long days. If, for example, your natural day length is 12 hours, and you start giving your pullets 15 hours of light, it can cause them to begin laying too early, and you can end up with problems because physically they aren’t fully ready to begin laying.
You can read more about this problem and how to prevent it in this Cooperative Extension Bulletin. It recommends waiting until a certain age before increasing day length and then doing that gradually.
Should I use artificial lighting?
Artificial lighting is effective, but should you use it? That’s a question only you can answer.
One view on this is that the seasonal variation in day length is natural. Seasonal egg laying is also natural. Chickens and other birds don’t normally lay year-round in most climates. As mentioned above, day length affects molting, growth and reproduction. Once we start tampering with the natural cycle by adding artificial light, we’ll get more eggs, but does that harm the chickens? Does it cause unnecessary stress? And there is also the potential that it could offset the time when they molt, causing them to molt in cold weather, when they need their feathers the most. Or without proper care, it could prevent them from molting, which is an important part of the chicken’s overall health and yearly life cycle.
Personally I prefer not to use artificial lighting partly because of the extra time and effort involved, partly because I think it may be healthier for the birds not to and partly because I don’t mind a bit of a break from eggs during part of the year.
On the other hand, artificial lighting definitely works. As long as you allow the chickens to molt about once a year, take good care of them and supply them with a good quality feed, the artificial lighting is not known to reduce their lifespan. If you depend on the eggs or if you have customers who depend on you for their eggs, you may need to consider it.
Breed Selection
Some of the breeds that we carry that are considered better winter layers are: Barred Rocks, Black Giants, Buff Orpingtons, Delawares, Dominiques, Rhode Island Reds, Speckled Sussex and Wyandottes.
In general, the larger, dual purpose breeds will tend to lay better in winter than the smaller, lighter breeds. I believe that has more to do with other factors than it does with sensitivity of particular breeds to day length.
I’ve not found a conclusive study of breeds and their sensitivity to day length. If you know of such a study, I would be very interested to find out more.
Conclusion
If your chickens are starting to lay less this time of year, it’s likely a result of days getting shorter. In future articles, we’ll look at other things that affect egg production, such as stress, nutrition, temperature, parasites and disease, broodiness, predators and “egg eating.”