Question for people who incubate chicken eggs.

[PopPop63]

Why do you use water in the incubator and worry about the humidity? I mean if a hen sat them she wont be adjusting the humidity. I also hear people doing "dry hatch" and getting better results than the 50/70% humidity thing.

 

[Jojociita]

Thing of if you just sat your bare butt on a bunch of golf balls for 21 days with minimal movement excepts to eat drink and restroom.. it’d get kinda sweaty the humidity game we play is to mimic (to the best of our ability) the environment under a momma hen. The eggs have to lose a certain amount of humidity to hatch (I.e. they need an air cell large enough to internally pip into before they externally pip, and it needs enough oxygen in there to let them take a few first breaths), but if they’re not enough humidity, the egg loses too much moisture and there’s no more room for the chick to hatch and it gets all shrink wrapped in one of its inner membranes Dry hatching(dry incubation technically) is great for some breeds, not for others. (Black Copper Marans? Dry. Silkies? Dear god no pls, normal 50% for the first 18, and 65%-75% for the last or their big heads get stuck)
Plus, even in a dry incubation you bump the humidity to 60% - 70% during the last 3 days! This way the chicks can take their insanely long amount of time to hatch without drying out and getting stuck.

It’s a frustrating balancing act and if I had a broody to assist, I’d leave it up to her. Alas I hatch as a hobby for a coworker who’s es rarely broody. I keep the fluff balls for a week or two, then return them to him so he can continue raising them indoors until they’re big enough to integrate into the flock!

 

[BrookeP]

Why do you use water in the incubator and worry about the humidity? I mean if a hen sat them she wont be adjusting the humidity. I also hear people doing "dry hatch" and getting better results than the 50/70% humidity thing.

I have never heard of dry hatch, I will have to look that up. We hatched our first chicks last April and out of the 19 fertile eggs 17 hatched. I was just going by the directions on my incubator and I believe it was the 50/80 or 50/70% like you said. It did a great job. I could imagine being under a chicken for 21 days or so it would get a little humid under there with their body heat and bedding they're on. Obv the best for hatching eggs would be the hen and idk the science behind the incubators and humidity but I trust they are doing it for a reason. We had a great outcome with our incubator.

 

[Ridgerunner]

Why do you use water in the incubator and worry about the humidity?

An egg needs to lose a certain amount of moisture through the porous shell for the chick to hatch. If you follow this Mississippi State incubation trouble shooting guide you will see different problems caused by too much or too little moisture loss.

Trouble Shooting Failures with Egg Incubation | Mississippi State University Extension Service (msstate.edu)

Luckily for us the window of how much moisture can be lost and the egg still hatch is fairly wide.

I mean if a hen sat them she wont be adjusting the humidity.

That has been studied. She does adjust humidity.

I also hear people doing "dry hatch" and getting better results than the 50/70% humidity thing.

And some people get total failure when they try that. Different humidities work for different people. Different incubators work differently, Still Air versus Forced Air just one example. The temperature and humidity of the air going in the incubator make a difference. The height above sea level (affects air pressure) makes a difference.

The operations that hatch 1,000,000 or more chicks each week in different hatcheries have studied incubation a lot. That's where most of this stuff comes from. They want to do the best they can hatching eggs because a small percentage difference in hatch rate can mean a lot of chickens. If they move an incubator from one location in the incubation room to another they have to restudy what humidity works best there.

 

[PopPop63]

The operations that hatch 1,000,000 or more chicks each week in different hatcheries have studied incubation a lot. That's where most of this stuff comes from. They want to do the best they can hatching eggs because a small percentage difference in hatch rate can mean a lot of chickens. If they move an incubator from one location in the incubation room to another they have to restudy what humidity works best there.

I used to install water treatment for hatcheries for the humidifiers. I knew they studied it and all that. I just see different people having better luck with a total dry hatch or a dry for 18 days then humid, and wondered how many people do that and how it works for them. When i was young we never added water to the incubator and it ran about 70% hatch rate or the eggs that actually began to develop. Infertile eggs were always a 0% hatch rate lol

 

[R2elk]

I used to install water treatment for hatcheries for the humidifiers. I knew they studied it and all that. I just see different people having better luck with a total dry hatch or a dry for 18 days then humid, and wondered how many people do that and how it works for them. When i was young we never added water to the incubator and it ran about 70% hatch rate or the eggs that actually began to develop. Infertile eggs were always a 0% hatch rate lol

To "dry hatch" is not as simple as not adding any water. People who live where their ambient humidity is 60% can "dry hatch" by adding no water because the humidity in their incubator will be around the mid 30% level. They still need to add water to get the humidity up during the actual hatching stage.

I have to add water to "dry hatch" here because my current humidity in the house is 13%. I add water to get the humidity up to the mid 30% level. Technically it is a "dry hatch" because of the level my humidity is at the mid 30% level that those with an ambient humidity of 60% get without adding any water.

If I did not add water, my incubator would drive the humidity down to 0% causing a total hatch failure.

 

[Jojociita]

I used to install water treatment for hatcheries for the humidifiers. I knew they studied it and all that. I just see different people having better luck with a total dry hatch or a dry for 18 days then humid, and wondered how many people do that and how it works for them. When i was young we never added water to the incubator and it ran about 70% hatch rate or the eggs that actually began to develop. Infertile eggs were always a 0% hatch rate lol

Totally get that. From my limited experience, when working with DIY incubators all completely IoT, controlling humidity is a hair pulling nightmare. My first tries were way too high way too low, too much fluctuation.. it was a mess. I did do a dry hatch (dry incubation) on my current bator of Black Cooper Marans and Olive-Eggers. Lock down is tomorrow so we’ll see, but my last attempt was an 80% rate which was huge for me. So I really only had to fret over humidity for the last 3 days where I was actually off for the weekend and my birthday so I was there to fuss with it. It just made it far less stressful for me at least. Less of a chance of mushy chicks or malpositioned pips. I’d never try it for breeds like silkies because they need all the humidity their giant heads can get (and even then I have a special little one who just pipped upside down , bust esp dark shelled eggs that lose water way slower than other breeds, it just gives me a higher success rate. We’ll see on the BCMs tho. Incubation outside of a hen is all unnatural anyway so people are constantly experimenting and seeing what helps for a wider range of people. Not everyone (myself included) hatches frequently or even for a flock. Heck, I wanted to try it so my coworker gave me a bunch of fertil eggs and it’s been rewarding, devastating, but highly intriguing and I’ve gained a multitude of knowledge. I keep them for a week or two as they jump about and run around like narcoleptic cotton balls, then I bring them back to him and he introduces them into the flock after brooding them a few more weeks. His hens rarely go broody (even the silkies) so he was happy, I was happy, and the floof butts were too! Works out

 

[Stanpott]

I use egg weight loss, in my waterbed incubator I do dry hatch, but even after a few hatches I still monitor egg weight loss to be sure I'm on track. It is very easy to do and I don't care if you dry hatch or not if you monitor egg weight loss you can adjust BEFORE it is too late. You can draw lines around the air cell but by the time you can be sure that the weight loss was too much or too little it is too late to do anything. Here are my simple instructions I wrote for incubators I built. If you are really committed to dry hatch but your eggs are losing weight to quickly, aside from adding water you can vent less or turn the temperature down slightly, if you are hatching with added humidity, just adjust the humidity.

I'm having trouble finding any simple written instructions for monitoring incubation humidity by egg weight loss, and yet it is so simple and I would never want to rely on a hygrometer again and when a hatch goes badly, I want to be confident that it was or was not a humidity issue.
Day#1...weigh every egg individually on setting, and write the weight on the shell (eg 56g)
Periodically during incubation weigh 5 or 6 random eggs and calculate the weight loss.
Eggs need to lose 12-13% of their weight by day 18 of incubation, but just to keep it easy, use 12% which works out to .67%/day and understand that anything in the range of 0.6-0.7% is good. If your weight loss is higher, then you will need to increase your humidity to stay in the optimum range, if the weight loss is lower, you need to decrease humidity
Anyways, many instructions I see say to batch weigh your eggs on day one, I say to weigh them individually on day one because at some point most of us like to remove quitters and non starters from the incubator so if you have a batch weight for 40 eggs and on day 10 you take ten eggs out, your initial weight isn't going to work anymore!