While waiting for feed testing results; how much light do hens need to lay eggs

[saysfaa]

I see many places that say hens need 12 to 14 hours of light to lay eggs.

Obviously, that isn't the whole of it because otherwise hens would not lay eggs between September 20th-ish and March 20th-ish, unless one lived very near the equator.

Last time I researched this, I found that hens need 12+ hours of light for full production of eggs. I think I remember 14 to 15 or 16 hours for maximum production but either way, what explains the extra weeks before/after the equinoxes?

It seems, they need about 9 hours for any of them to produce any eggs.

I doubt that is all there is to it. Among other things, some are more sensitive to light levels than others.

Also, how much light is needed to count as those hours?
Is it only the intensity or does wavelength matter?
Do clouds change the intensity and/or wavelength of sunlight?

Edited from simply saying "sorry" as the entire message for hitting the wrong key.

 

[Shadrach]

I find it impossible to believe that a reduction in feed quality, whatever that may be, is responsible for the reported reduction/ceasation of egg laying as some people are suggesting.
Firstly, there are a range of feeds with differing percentages of nutrients and for the the reduction in feed quality theory to stand up there would be a minimum standard at which no hens laid any eggs. This doesn't seem to be the case.
There may be a case that hens may lay less eggs with a reduction in feed quality but hens that don't get fed any commercial feed still lay eggs.
Ime stress and weather have a far greater impact on egg laying than any particular percentage of nutrients.

I've got hens laying with 9 hours of daylight, during moult and poor daylight quality. So have many other people.

 

[WallyG74]

We’re getting about 10.5 hours of good light right now and my hens are laying like champs.

 

[saysfaa]

Anyway, I'm not dismissing any other proposed explanations of why so many flocks have had unusual laying patterns lately. But instead of simply going back and forth with "I think" and "but I think".... until some new information comes - such as test results...

Around here, we can expect very heavy, low cloud cover from October through December. Then January is usually much colder. And clear.

This year, the very heavy, low cloud cover stayed. With, literally, two 15 min breaks. One last week and one the week before. I pay close attention to it due to Seasonal Attitude Disorder.

It became too dark to read a newspaper noticably earlier.

Turns out, clouds change the wavelength that reaches the earth, also...
Link

And wavelenght affects how often a hen lays an egg, even if the hours of exposure to the light are the same... link

These are not thorough study of this... it is just enough to be interesting. And, perhaps, a small piece of the puzzle.

 

[centrarchid]

I see the following impacting egg production when controlling for genetics: photoperiod, age of hen, feed quality and amount, and finally cold stress. Later is really impactful when photoperiod is marginal.

 

[Fallenone05]

I'm just thinking it was the stress and weather. I wouldn't be laying either if I was a chicken until a week or two ago. We had another temperature plummet this weekend and I'm fully expecting eggs to slow again. Not that I'll complain, I already have way too many and only a fraction are laying anyways

I went from getting over a dozen a day to three or four a day again. It was spring (low to mid-70s) with heavy sunshine. A cold front blasted in. Then last week we got a half foot of snow and until Wednesday morning we're in an ice storm. My birds have a cold from the SUPER SUDDEN drop in temps (seriously from the 70s to the upper 30/low 40s over night) and they hate it right now. I feel so bad for them.

Edit to add that it was 55 this weekend after the snow before immediately plunging to 29F as the high.

 

[saysfaa]

I looked up the daylight length, we get about nine hours on the shortest days. That is going by sunrise and sunset times. In real life it is a bit shorter on the heavily clouded days that are common in late autumn.

That may contribute to my expectation that stopping for a month or couple of months is normal.

Edit to add, and a bit longer on clear days because we can see pretty well for a while before and after the official moment of sunrise/sunset. Moreso, the further from the equator one is.

 

[SourRoses]

You should have spankings with a keyboard!

 

[JacinLarkwell]

Hm, the link says red light resulted in the most eggs.

Eh, it was an idea.

Do you have feed from then?

No. It's not the ones people are getting up in arms about anyways. The week from hell was aptly named (-20 days, and several losses to the different flocks) and all the birds exposed to the light apart from a trio of hens were moved under the lights because they were in danger of succumbing to the cold.

 

[Sally PB]

And wavelenght affects how often a hen lays an egg, even if the hours of exposure to the light are the same... link

Very interesting. Now I'm really curious if the polycarbonate panels I put on the roof of the run change the quality of the daylight enough to mean anything. They're 83% transmission (actually, less now due to the snow/ice on them) which seems great in the summer, but perhaps not so great now. I can describe the light most days as: dim, dimmer, watery, gloomy, and dull.