Poultry Science
One of the most common, practical reasons we keep chickens is because we like the eggs they make. We basically have a deal with our hens: If we raise them well, they’ll make nutritious, healthy eggs for us. In order for them to make those “farmfresh” eggs, though, hens require a few things:
• GOOD NUTRITION Layer diets contain optimal protein, energy and proper amounts of calcium and phosphorus among other nutrients.
• GOOD WELFARE Stressed birds don’t produce eggs.
• ADEQUATE LIGHT Hens need approximately 12 to 16 hours of light everyday while “in lay.”
Lighting can be somewhat of a tricky subject because the amount of natural light you get depends on where you live relative to the equator of the earth. For example, if you live at the North or South Pole, you literally have a 6-month night and a 6-month day, depending on the time of year.
In contrast, if you live on the equator, the differences in light between winter and summer are barely noticeable. You get basically 12 hours of lightness and darkness each day of the year. The point is that depending on where you live, there are times of year you probably don’t need to worry about light and there are times of year that your hens may not be receiving enough light. This is further complicated by the likely reality that different chicken breeds have slightly different requirements for light with respect to egg production.
Before we talk about the practical physiology of light and egg production, it’s important to realize that if you decide to not offer additional light to your hens, your hens will be perfectly fine. Think of additional light as one of the options on your car, such as a moon roof, that you don’t need for the car to work perfectly well.
If you are happy with your hens not producing as many eggs in the winter (when days are shorter and there is less light), then there is no reason to add supplemental light. However, if you want to add a few more eggs to your winter harvest, the remainder of this column is meant to provide a practical primer on how to supplement light safely to your hens.
Note: A hen, no matter the breed, can only produce an egg a maximum of once every 26 hours, so if you think you are going to get two eggs a day from each hen if you double the light, it doesn’t work that way!
Natural Lighting
Before we talk about supplemental lighting, it’s important to also discuss natural lighting. In general, as the days get longer in the spring and summer, layers are more productive. This is why the most opportune time to buy chicks is between December and January because the chicks will be sexually mature when the daylight begins to lengthen in the spring.
Likewise, about once a year, hens begin to molt. Molting is about rest not reproduction. Molting is a natural process during which the hen begins to lose feathers and stops laying eggs;
think of it as a well-deserved break. This is an important process because it allows time for the hen to regain the necessary components within her body to lay eggs in preparation for the next laying cycle. Often, this occurs in conjunction with a decrease in daylight.
Therefore, before you consider supplemental light, think about maximizing natural light. To that point, make sure you have windows in your coop that are ideally south facing (assuming you are reading this in the Northern Hemisphere) and north facing
(if you are reading this in the Southern Hemisphere).
Artificial Lighting Tips
There are a few hours of wiggle room in the previous recommendation for at least 12 to 16 hours of light per day. In order to maximize egg production, moving toward 16 hours will help increase production. Here are some basic rules to follow when integrating supplemental light into your chicken coop
don’t provide more than 16 hours of light a day. Too much light (in duration or intensity) can lead to behavior/welfare issues including cannibalistic behavior.
One bulb per 200 square feet of indoor space is typically sufficient.
Place the bulb in an area where you can reduce shadows the most. A
15- to 25-watt bulb or equivalent is typically sufficient. You can get a timer to provide the additional light, which you should supply in the morning.
For example, if you need to provide an additional hour of light and sunrise is at 6:05 a.m. at your latitude, put the timer on for 5:05 a.m. This is important because if you don’t provide your hens with at least four hours of continuous light, your hens can develop eye problems that can lead to blindness.
You can get a lux meter (a handheld devise that measures the amount of lumens the bulb produces) to measure the intensity of the light (aim for around 200 lux in the feeding areas), but in general, the lighting should be bright enough to read a book in all areas of the indoor space.
don’t put the light in the nest box. (Hens like the nest boxes darker.)
Watch your hens’ behavior and the quality of the eggs they are producing. If you provide too much light, they can be over-stimulated which can cause aggressive behavior. In addition, you may see “double yolkers” (eggs with two yolks in them) more often.
If you want to get fancy, get an LED light. LEDS are interesting and optimal because they produce higher levels of intensity in the blue or red spectrums (which are not visible to the human eye) but are visible to poultry. These spectra seem to be optimal with respect to behavior and production.
One important consideration is the balance between production and molting. As noted, molting typically takes place annually — they typically won’t molt their first year of life — when light decreases — typically during the fall or winter. Because the length of the molt is variable (4 to 16 weeks), it can be challenging to “know what to do” when you have different breeds and different ages which can cause different molting periods.
For backyard birds, there is nothing wrong with a play-it-safe approach — especially with older birds that are more likely to have reproductive problems. However, for younger flocks, a short molt can be integrated into your normal annual lighting program in order to allow molt and optimize production.
If your chickens are 100% pets with an added bonus of a few eggs a week, don’t worry about adding light. However, if your hens are the source of your daily omelets, think about supplemental light. That being said: Keep an eye on your birds as you add supplemental light for double-yokers or any welfare/behavior issues such as overaggressiveness. Regardless of what you do, I hope you appreciate how amazing your birds are. A 5- to 6-pound hen that makes more than 30 pounds of eggs in one to two years is pretty amazing!