Winter Egg Laying and Adding Light

[Penpal]

My hen started laying again. It happens every year, they stop then start up again. Everyone knows that if you leave a light on, they keep laying.

Okay, but I just realized that with the longer days my chickens are eating more. They stop eating when the light is too dim. If I hold a light over the food, they eat. Could the change in egg laying actually have more to do with the increased amount of food they eat?

 

[aart]

Probably a combo.
The light stimulates the pineal gland located behind the skull between the eyes which triggers the rest of the hormonal system. They should always have feed available when the light is on, and they do eat more when laying.

 

[K0k0shka]

The two are interconnected, yes. Physiologically, egg laying or stopping is triggered by the amount of light, but the reason behind that (the evolutionary adaptation) is that in the winter food is more scarce, and the amount of daylight they have in order to find and eat food is shorter, so they don't have enough time to gather enough calories to produce eggs. Chickens are scavengers and eat little bits at a time throughout the day, they don't have a couple of large meals the way carnivores do. So they need a certain length of day to be able to eat enough little portions to add up to enough calories.

 

[NatJ]

My hen started laying again. It happens every year, they stop then start up again. Everyone knows that if you leave a light on, they keep laying.

Okay, but I just realized that with the longer days my chickens are eating more. They stop eating when the light is too dim. If I hold a light over the food, they eat. Could the change in egg laying actually have more to do with the increased amount of food they eat?

I can't easily find the sources now, but people did look into that about a hundred years ago.

I'm pretty sure they decided that the actual light was what made the difference, not the change in amount of food.

I don't remember how they tested it-- probably arranged to have two groups of chickens that ate equal amounts of food but had different amounts of light. Encouraging the unlit ones to eat more food during the time they do have light, or limiting feed to the ones with more light, would be two ways to make the amount of food match. Or maybe they provided food to both groups for the same number of hours each day, during a time that they all had enough light to eat. That would mean the ones with extra light had no extra time in which to eat, but could eat as much as they wanted while they did have light.

 

[Penpal]

It wasn't the amount of food. It was the amount of protein I was wondering about. They can't get bugs when there is snow on the ground.

 

[NatJ]

It wasn't the amount of food. It was the amount of protein I was wondering about. They can't get bugs when there is snow on the ground.

There have been lots of experiments about what protein levels should be in the feed to get good production from hens.

If they are not getting bugs in the winter, they may need more protein in the feed supplied by a person-- but that can be done without changing the amount of light. That makes it pretty easy to test protein vs. light as the cause of the laying.