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Expert tips and tricks for backyard chicken keeping

Why do chickens need sunlight?

Chicken health, General

Chickens get very uncomfortable in warm and hot weather, however they do need some sunlight to survive.

Just like humans, chickens need sunshine too. The UV rays from the sun provide essential Vitamin D to both people and pets. Vitamin D is essential for backyard chickens’ optimal health and egg-laying ability.

The sun determines their daily sleep/wake schedule and the light helps them synthesize and produce the hormones required for egg production. However, chickens only need a moderate amount of sunlight and do require shade. Too much exposure or excessive exposure to sunlight can prove fatal.

In the height of summer, shade is a welcome relief for your birds. While it’s okay for chickens to get some exposure to the sun, especially as they free-range in your back yard, they need an area where they can cool down and maybe enjoy a dust bath.

Chickens can suffer from heatstroke very quickly when they get overheated – so you must ensure that they have some cover from the sun.

Sunshine also plays other important roles in the life and health of a chicken. Obviously, chickens don’t wear watches or rely on clocks to tell them when to head into the coop to sleep. That’s all based on the sun going down.

Diminishing hours of daylight in autumn also signal to a chicken that it’s time to start the annual moult. But most importantly, ultimately it’s sunshine that provides fresh eggs.

In order to consistently lay eggs, hens need about 16 hours of daylight and 8 hours of darkness when they’re roosting. Once less than 12 hours of daylight is available, egg production slows down considerably if not ceases completely. Although you might think colder weather causes a decrease in egg-laying, that’s not the case. Even chickens in warm climates produce fewer eggs once the daylight hours decline.

Egg production is governed by the hen’s pineal gland (part of the endocrine system). The pineal gland sits behind the hen’s eyes and is activated by the light. As the days become brighter and longer, the hen’s pineal gland will send a hormone to her ovary to begin egg production.

According to the FDA, inadequate levels of vitamin D in the diet of a chicken for more than two or three weeks may cause bone weakness, fractures or joint problems, and potentially death in birds not exposed to direct sunlight daily. Without any sunlight (or Vitamin D supplements), your chickens would stop laying eggs.

A  Vitamin D deficiency in chickens can lead to:

  • thin, broken eggshells
  • low egg production
  • brittle bones
  • wry neck
  • splayed or weak legs
  • trouble walking and standing
  • osteoporosis/rickets
  • deformed keels
  • stunted growth
  • soft or broken nails, toes or beaks

It’s also thought that not getting enough sunshine can lead to aggression, feather pecking, and overall unhappy chickens.

Chickens also need to keep their feathers oiled to prevent them from becoming brittle and to help with insulation and waterproofing. They have a single oil gland near the base of the tail, referred to as the preen gland. Your chooks pinch this gland with their beaks to extract a waxy oil, which they then apply as they pass their feathers through their beaks. That oil produces Vitamin D when exposed to sunlight. That Vitamin D is then absorbed into the body through the skin, much like humans.

Chickens also absorb Vitamin D through their eyes. Unlike humans who only see the red, blue-green color spectrum, chickens also “see” UV rays. Not only can chickens see better than we can, but they can also see a wider range of colour, including UVA and UVB rays. And therefore they can absorb Vitamin D through their eyes.

Depending on their age, chickens need between 3,000 – 5,000 IU/kg of Vitamin D daily.  This can be easily achieved by allowing your chickens 15-30 minutes outside in the sunshine each day.

Overall, chickens need sunlight; it sets their daily schedule; it keeps them happy and healthy. They love being outside, and the light has a lot of health benefits; it’s an excellent source of vitamins, and it’s what chickens need to lay eggs.

Direct sunlight is great, but only in moderation. Too much, and it’s another issue. It’s certainly not good for chickens to be out for too long in direct sunlight, especially in the summertime.

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