The Stickies don't seem to cover this yet.....

[Bobbi Lou]

I'll start by saying that I've read a lot of the incubation Sticky Threads, and they've been very helpful with a lot of my incubation questions - thank you to everyone who contributed to those! But with this latest hatch, I've run into a problem that the stickies don't seem to explain.
Not a single one of this batch of 48 hatched; about half of them had never begun to form. Of the remaining 24 or so, about 2/3 looked like they died around day 14, with the remaining few looking like they died right around day 18. There were no temperature of humidity fluctuations of which i am aware, and I was watching it pretty closely. (I have gotten a second thermometer/hygrometer for the next hatch, in case the one attached to the incubator isn't accurate). There was one very weak chick that was still alive when I opened the eggs on day 24, but it died within a minute or two (and not because it was opened carelessly; I gently opened the egg from the air pocket side, and it was clearly almost gone already.

Several of the chicks had deformed feet, which I have read may indicate too high a temperature; is this correct?

All of the eggs were from my own chickens, and the parent stock is all in good health.

The temperature was set at 103 because I thought my thermometer read a degree or so low - again, I'll be able to check this once I get my new thermo/hygro calibrated.


Is there an easy explanation for why they would all die right around the same time? Could it be the rooster's genetics? (I narrow it down to rooster because the eggs were from multiple hens).

Or does anyone have other suggestions? I'd really like to have another batch going by Friday, but I don't want to chance killing them all.
Thanks in advance for any help you can give!

 

[wynn4578]

Pretty much what you described sounds like the temp was too high. The further along an egg is in development the more prolonged high heat swings affect it. When the temperature drops (especially in later development) as long as the drop isn't too drastic or for too long the eggs can recover although it may hatch a little late. Heat is a different story. I don't know that there's a definitive temp or length of exposure but at high temps an egg will begin to develop some may hatch but most will end up dying. Your always better off too be a touch on the cool side than too hot. I know anything over about 101 begins drastically reducing your chances of success. It's best to be in the 99 to 100 range.

 

[Bobbi Lou]

99-100 even for a still-air incubator? From what I've read the general consensus seems to be 99 for circulated, 101-102 for still-air.
With my previous hatch I had it set on 99, and the eggs closer to the heating element had a much higher hatch rate than the eggs farther away from it, so I figured that wasn't quite warm enough.....

 

[wynn4578]

In a still air incubator you run the temps a little on the high side to accommodate the eggs that are sitting in the "cold" spots.

Personally if I were using a still air incubator I would shoot for 100 at the top of the center egg then spot check the corners to see what my temps are there. If I were below around 98.5 I would make some adjustments and hopefully all my eggs would end up somewhere in a 99 to 101 temp range. This is just my opinion but I personally i don't like to be above 101.

Hopefully someone will post the uses a still air on a regular basis. They would know some tricks that I don't know.

 

[AmyLynn2374]

99-100 even for a still-air incubator? From what I've read the general consensus seems to be 99 for circulated, 101-102 for still-air.
With my previous hatch I had it set on 99, and the eggs closer to the heating element had a much higher hatch rate than the eggs farther away from it, so I figured that wasn't quite warm enough.....

In a still air incubator you run the temps a little on the high side to accommodate the eggs that are sitting in the "cold" spots.

Personally if I were using a still air incubator I would shoot for 100 at the top of the center egg then spot check the corners to see what my temps are there. If I were below around 98.5 I would make some adjustments and hopefully all my eggs would end up somewhere in a 99 to 101 temp range. This is just my opinion but I personally i don't like to be above 101.

Hopefully someone will post the uses a still air on a regular basis. They would know some tricks that I don't know.

The heat in a still air incubator is layered with the warmest layer near the top and cooling as you go down. That is why it is recommended that in a still air incubator you should have your temp at about 101.5 (101-102F) measured near the tops of the eggs. This is supposed to provide the inside of the egg with a temp of 99.5.. In a forced air (theoretically) the air is more even throughout the incubator and 99.5 should give you the adequate amount of heat.
You don't want to see the actual temps going above 102 in a still air if you can help it, but you do want to average around 101.5 ideally.

Often multiple deaths at the same stage either point to temps or humidity. You can take a look at this site:http://msucares.com/poultry/reproductions/trouble.html It may help. And there is also this: http://ufdc.ufl.edu/UF00008570/00001/2j

 

[Bobbi Lou]

Thanks, y'all! I tested out my new thermo/hygro, and it seems to be pretty accurate (I've only had it for a day, so still need to do some testing before trusting it completely). I then compared the new, apparently accurate one to the built-in hydro/thermo in the incubator, and the incubator was consistently off by about 4 degrees Fahrenheit and anywhere from 11% to 20% humidity!!! I had the thermostat set for 101.5, and it never got above 97.5.
I have an old manual incubator that I just hadn't used since I didn't have a thermo/hygro for it, but since I had to get one to test my new incubator anyway, I think I'll be returning the new, defective one and running some tests to see if the old, manual one is reliable.
Thanks for all the info! It was very helpful!

 

[Egghead_Jr]

I would never trust the built in temp/hygrometers in inexpensive incubators. Well, I'd even check high end ones but frankly would never purchase one to begin with but I digress.

Don't return your small hygro/temp combo unit calibrate it. Perform a salt test to calibrate the RH reading and use a medical thermometer from your medicine cabinet to calibrate the temperature. Mark the corrections on a piece of masking tape and stick it to the incubator as a reminder.

How I salt test:

Fill a milk or juice cap with salt. Add drops of water until saturated. Pour off standing water.

Put hygrometer and cap in zip seal sandwich or quart size bag. I allow small pillow of air.

Wait at least 4 hours and note the RH reading. Subtract reading from 75 and write that calibration number on masking tape.

Example: Your reading is 82%, 75-82= -7. You'll always subtract 7 from your readings for true RH.


Side note: The battery power will effect temp and RH readings on electrical units so calibrate at the start of each season and during if you are a person who hatches more than twice in a row.