There are both Pros and Cons to lighting your chicken coop in the winter. We will discuss both here.
Pros of lights in your coop
Egg laying is a function of light, so as winter approaches and the days become shorter, your chickens will produce fewer eggs. Chickens also generally molt during the late fall, which can also affect egg production.
Adding light stimulates the pituitary gland, which signals your chicken to lay eggs. Your hens will need 12-14 hours of daylight to produce eggs, so depending on how much daylight there is in your area during the winter months setting a light on a timer to come on in the mornings and again in the evenings to extend the “day” will increase egg production.
If your winter months are particularly cold, the light can also add some warmth to the coop. However, this may not be required as chickens are covered in downy feathers that keep them warm and they often do not need supplemental heat unless it is below freezing.
Of course lights in the coop can benefit you as well, as they can give you some light in the morning and evenings while you are cleaning, feeding, collecting eggs, or just making sure all is well in the coop and with your chickens.
Cons of lights in your coop
Potential problems with adding lighting is that chickens naturally, as the lighting reduces, lay fewer eggs. While, unproven, some chicken experts believe that by having chickens lay year around without this natural break, can cause health problems including ovarian cancer, vent prolapse, and egg binding.
Another potential problem with a light in the coop is the possibility it gets too warm, or could potentially start a fire, so make sure the light is wired correctly and that the light is not within your chickens reach.
A light, which extends your chickens days in the winter may also result in stress and bad behaviors such as pecking or cannibalism.
Type of lights
Some chicken experts suggest using a red light in the coop. This will not result in egg production, but some experts believe it can calm chickens as well as prevent bad behaviors, because they can not recognize a waddle or comb in the red light, so are less likely to hen-peck or engage in cannibalism.
If you do choose to put a light in the coop, us a low watt bulb 25 – 40 watts and do not leave in on 24 hours a day.
Do not use “shatter proof” bulbs as they can gas-off toxins that are fatal to chickens. However, you do want to make sure the bulb can not be pecked or otherwise disturbed to prevent it from breaking. You do not want glass shards all over the coop where the chickens may eat or step in broken glass.
Make sure your chickens are well fed in the winter and give supplements to help them keep up with the demands of laying throughout the winter.