???Why Do We Need Humidity???

[The Wolf Queen]

Just out of curiosity I was wondering why we need humidity during incubation? I mean we don't need to worry about it when someone uses a broody to hatch eggs but we do when we use an incubator. I understand that if not the hatchlings would get stuck to the membranes of the egg but how come you don't need to worry about it with broodies? Just another random question from inside my mind lol

 

[Tala]

Uh, here's the untechnical explination: Because most animals' bodies put out moisture from their skin. Even animals that don't sweat, like dogs and chickens, their skin cells still "breathe" out moisture.

 

[Ridgerunner]

The egg needs to lose a certain amount of moisture during incubation. If it loses too much, the chick dries out in the egg. If it does not lose enough, it can drown during the hatch. I think you already knew that.

There was a thread on here a while back where someone was measuring the humidity under a broody. The simple answer to your question is that the broody controls temperature and humidity.

 

[raimnel]

Low humidty days 1-18. Higher hymidity 18-21.... and the hen gets off the nest towards the end and gets wet. God programed them that way so we didn't have to worry about it.

 

[Kung Foo Chicken]

Humidity is essential. Under a broody it is 50-55% for all 21 days.
I put probes under her in an effort to improve my incubation since
she was getting much better % hatch than I.

Now that is chicken crazy!

 

[rebelcowboysnb]

Under a broody it is 50-55% for all 21 days

Ok but humidity is relative to air exchange.... Even if you match the humidity you would also have to match the air exchange around the eggs. If not then the evaporation rate in the egg still would not be the same.
http://cmfarm.us/ventilation.html​

 

[dianneS]

When I've stuck my hand under my broody it feels kind of steamy warm in a way. I was wondering that my self and when I felt around under her feathers, it was kind of "humid" under there!

I personally don't obsess over the humidity in my bator. I don't even monitor it at all. I used the dry incubation method and didn't add water until lockdown, but I still ended up with some dry membranes and shrink wrapped chicks that I had to help out. Recently I just added water to the wells from day one, waited for them to evaporate, gave it about a day or two with the wells dry. Filled them up again, let them evaporate, and finally filled them one last time at lockdown. I had a great hatch and non of my chicks had any trouble and no shrink wrapping or dried membranes.

But as to why we need humidity, I guess the dry air of the bator is too dry. Mom hens must give off a lot of moisture. That brings me to another question, do chickens sweat?

 

[Kung Foo Chicken]

Quote:
Ok but humidity is relative to air exchange.... Even if you match the humidity you would also have to match the air exchange around the eggs. If not then the evaporation rate in the egg still would not be the same.
http://cmfarm.us/ventilation.html

This is true. However, it would be very hard to measure air exchange of a broody.
This brought hatch rate from the 50% range up to the 80-100% in an LG with
weather strip tape between top/bottom (which is what I use and doesn't apply to any
other incubator). I watch the air cell size and it's all guess work then to determine if
I'm doing ok compared to photos of the broody hen's eggs at various stages of
incubation.

If I'm keeping close to the hatch of the broody, for a hobbyist that is fine with me.
This may not work if I perhaps purchased a very good incubator.

It is saving me money so that I'll use the hatched chicks I get from RIR eggs
that I buy for 1.00 a dozen to sell the chicks. This way I can move up from
10 LG's that I mostly got for nearly nothing to help at least purchase a
Forma 3033 Lab Incubator with full controls. So I can skip expensive
plastic incubators to go beyond the next level.

Of course I'll have to figure out what works with that too.