How important is direct sunlight to chicken health?

[EmmaDonovan]

I don't know if chickens need sunlight to make vitamin D the way we do or if they need it for some other health reason. We're in the desert so our runs and pens are covered to keep the sun off of the hens. They only have direct sunlight as it peeks through the sides of the runs in early morning and late afternoon. In the winter this is pretty minimal.

We have 10+ hours of daylight in the winter (14+ in summer). Is there some reason hens need direct sunlight for health (not egg laying), or is ambient sunlight enough?

 

[azygous]

As humans absorb vitamin D from direct sunlight, so do chickens. Only chickens do not absorb it through their skin as we do. Chickens absorb vitamin D though their feathers. This is why you will see chickens lying on their sides with a wing unfurled to capture as much of that precious D as they can.

They need vitamin D for organ function, but also for egg laying. If they don't get enough vitamin D, they can nibble on unlimited oyster shell and not absorb enough of it to support egg laying.

If a hen doesn't absorb enough vitamin D, thus limiting the amount of calcium they can absorb, it can affect more than just egg shells. Low calcium can cause a heart attack when her body is trying to find enough to build a shell on the egg she's laying as her body resorts to using the calcium in her blood instead. Low calcium can also affect how easily she can pass the egg as calcium also controls contractions she needs to push the egg out.

Probably your hens are getting enough direct sunlight, but you will probably want to pay more attention to this knowing how important vitamin D is for absorbing the calcium that is literally keeping your layer hens alive.

 

[EmmaDonovan]

As humans absorb vitamin D from direct sunlight, so do chickens. Only chickens do not absorb it through their skin as we do. Chickens absorb vitamin D though their feathers. This is why you will see chickens lying on their sides with a wing unfurled to capture as much of that precious D as they can.

They need vitamin D for organ function, but also for egg laying. If they don't get enough vitamin D, they can nibble on unlimited oyster shell and not absorb enough of it to support egg laying.

If a hen doesn't absorb enough vitamin D, thus limiting the amount of calcium they can absorb, it can affect more than just egg shells. Low calcium can cause a heart attack when her body is trying to find enough to build a shell on the egg she's laying as her body resorts to using the calcium in her blood instead. Low calcium can also affect how easily she can pass the egg as calcium also controls contractions she needs to push the egg out.

Probably your hens are getting enough direct sunlight, but you will probably want to pay more attention to this knowing how important vitamin D is for absorbing the calcium that is literally keeping your layer hens alive.

That's what I needed to know, thank you.

 

[BigBlueHen53]

@azygous, do chickens ingest appreciable amounts of Vit D from preening their feathers, as cats do from licking their fur, or do they absorb it directly into their bodies from the feather shafts? This is fascinating.

 

[EmmaDonovan]

Probably your hens are getting enough direct sunlight, but you will probably want to pay more attention to this knowing how important vitamin D is for absorbing the calcium that is literally keeping your layer hens alive.

In the afternoons when everyone is more or less done laying we move the hens to mobile pens (quasi chicken tractors) that we can place around the yard where there are little tufts of desert plants for them to nibble on and soft dirt to scratch in. Those pens are covered with hardware cloth but no tarps so they get direct sunlight that way.

We can't do that during the hot months or we'd end up with roasted chickens but this time of year we can put them out for several hours each day. How much time in direct sunlight do you think they need each day?

 

[azygous]

I've lived down there where you are and worked in 117F temps for nine months out of the year, so I'm in sympathy for your chickens. At least one hour per day of direct sunlight will be plenty to absorb enough vitamin D.

As long as chickens have shade, they will be able to regulate how much heat they can handle from direct exposure by moving back and forth from sun to shade.

Here's a neat trick I learned from a desert ground squirrel, the little guys that look like chipmunks. If you dampen the ground where your chickens will be, the chickens can use that damp earth to shed the excess heat accumulating in their bodies. The laws of thermodynamics and entropy are that heat is drawn into cool.

I used to watch with admiration that tiny squirrel zipping around in 117F heat and pausing at each little bit of shady ground to prostrate itself to shed heat into that cooler spot. Here, on a 85F day, I dampen the dirt bathing area and my chickens sunbathe comfortably in the cool, damp dirt.

 

[azygous]

Recently, I used this system to treat a bullying victim in my own flock. Possum, an EE, is around five or six. She's never been especially self confident, so when the flock matriarch Louise, a nine-year old EE, decided she needed to totally stomp Possum, Possum went into total meltdown/shutdown. I saw the bullying, but decided to give it a few days to see if things would work themselves out. But I decided to do something when I found Louise pinning Possum down and pecking her senseless, many of the flock joining in.

Possum was in terminal victim mode, not eating, not wanting to roost, and behaving like a total door mat. I have a special fenced section in the run for bully victims. Possum resided in this protected space during the day for the next three weeks. It took every bit of this time to rehabilitate her, getting her over her fear and insecurities. But in the end, she miraculously regained her self confidence and lost her fear of Louise. She now confidently roosts right next to Louise on many nights.

During the first couple weeks of Possum's confinement, I took Louise out of the general population because I got tired of seeing Possum freaking out whenever Louise came up to the enclosure and intimidated her. So Louise spent her days in another run with the rooster. Around the end of the second week of Louise's absence, I was seeing fights among the other hens. It dawned on me that in the absence of Louise's enforcement of peace and order, the flock dynamics were in flux. I brought Louise back into the main flock.

Coincidentally, this probably helped Possum, as well. It's possible she finally got it through her tiny brain that Louise wasn't going to kill her. My flock quickly got back to normal, and peace has reigned since. Moral of this tale is that bullies often play an important role in the flock. It's best not to mess with it.

@azygous, do chickens ingest appreciable amounts of Vit D from preening their feathers, as cats do from licking their fur, or do they absorb it directly into their bodies from the feather shafts? This is fascinating.

That's an interesting question. Let me research it.

 

[azygous]

I found out that cats get most of their vitamin D from their cat food, not from licking their fur, although they get a small amount that way. Chickens get little to no vitamin D from preening.

When body oils are exposed to the sun, a precursor of vitamin D is produced, but it's extremely inefficient in chickens as a source of vitamin D.

As an aside, has anyone ever had a sunburned chicken? I had a hen who was stuck in molt for a year. She had a bare back that I had to spray sunscreen on after I saw her skin turning bright red from exposure. This was a daily exercise until finally feathers regrew.

 

[BigBlueHen53]

I found out that cats get most of their vitamin D from their cat food, not from licking their fur, although they get a small amount that way. Chickens get little to no vitamin D from preening.

When body oils are exposed to the sun, a precursor of vitamin D is produced, but it's extremely inefficient in chickens as a source of vitamin D.

As an aside, has anyone ever had a sunburned chicken? I had a hen who was stuck in molt for a year. She had a bare back that I had to spray sunscreen on after I saw her skin turning bright red from exposure. This was a daily exercise until finally feathers regrew.

Thank you, @azygous. I appreciate you researching this. I had always thought cats got Vit. C from self-grooming but have no idea where I first read that , it was so long ago. So chickens absorb it through their feathers snd not frim their skin like we do?

 

[azygous]

Chickens get vitamin D both through their feathers and their skin.

Direct sunlight is the best way to make sure chickens get enough D. It can be tempting to just give them a D3 supplement, but since it's fat soluble, giving it in supplement form on a regular basis can cause toxicity. But if the sun is absent for long periods, bolstering their D levels temporarily with the supplement can help.