I will never consider myself an "expert"...

[Panther Creek Poultry]

Daisychick-

I would weigh them today and then see what you have on day 10. if you have close to the 12% you will know to up the humidity and so on.

Just my 2 cents worth.

Sheila

 

[Dread Pirate Roberts]

Quote:
That's the key right there! I should have mentioned that it's all about the air cell and weighing the eggs is merely a tool to monitor the air cell and humidity is merely a tool to manipulate weight loss and thus air cell growth!

Quote:
I cannot form an opinion on the merits of weighing them at this point, but I do have two questions...

1. Do you have a gram scale?

2. If you do have a gram scale and have not been weighing your eggs, then what have you been weighing with that gram scale, eh?

Have you read that huge Hoss of a thread about humidity? I highly recommend it.

 

[daisychick]

Nope I don't have a gram scale.

I just have a food scale, I haven't checked what it weighs in.

I will try to weigh a few eggs just to get an idea of what they are losing.

 

[Pagemaker]

Wet Bulb vs. Relative Humidity

The relative humidity in the incubator for the first 18 days should remain at 58-60 percent or 87-89 (degrees)F., wet bulb. Increase the humidity during the last three days of incubation to at least 65 percent relative humidity or 90-94 (degrees)F., wet bulb.

Here is a chart that shows how to convert Relative Humidity to your wet bulb readings.

And here is a guide to how the air cell should be developing if the humidity is correct.

An excellent way to determine if proper humidity is maintained is to candle the eggs. The normal size of the air cell after 7, 14, and 18 days of incubation is shown. As incubation progresses, the air cell of the egg becomes larger because moisture is lost from the egg. Necessary humidity adjustments can be made as a result of the candling inspection.

Information taken from this webpage:
http://www.msstate.edu/dept/poultry/avianemb.htm

 

[Dread Pirate Roberts]

Quote:
Pardon me, but is there some reason that you've chosen to come into my fresh thread and regurgitate (via Copy & Paste) the same tired, old, generic information that does not apply to all of us in our various locales and has caused so many failed hatches?



Quote:
This is true, and "growing" the air cell can be thought of as the entire reason for manipulating the humidity. The humidity is merely a tool by which we attempt to properly "grow" the air cell. But, visually observing the air cell is so much more subjective and inaccurate than weighing the eggs on a gram scale.
Disagreement and debate are always welcome, threadcrapping and mindless regurgitation are not. Spare us the Ctrl+C, Ctrl+V unless you honestly have something to contribute.

Thanks!

edited to be nicer.

 

[pascopol]

Quote:
Weighting eggs individually is a lot of work, I do not mind it if it would improve the hatch.

But what you do if they lose weight univenly?

Lets say egg #1 lost 9% and egg #5 lost 12% by the same day?

 

[Dread Pirate Roberts]

Quote:
On my last hatch, the two eggs with the widest variation in weight loss had lost 9.1% and 12% on Day 18. Both of those eggs hatched.

I just average them all out and run with that.

Like school kids, there are going to be some that just don't test well, but will still make something of themselves.

 

[skeeter9]

Daisychick, since your kitchen scale probably doesn't measure is increments as small as grams, I suppose you could weigh multiple eggs at one time and monitor the weight loss that way. You should still get accurate enough information as long as you are weighing the same set of eggs each time. Guess it just depends on your scale?????

Napa Valley, thanks for the interesting information. I have been using dry incubation for a long time now and my hatch rates are much better. Since I don't have an accurate scale, I have taught myself to use the aircell size as a humidity guage. I keep a printout of the appropriate air cell size right by my bator to compare to at days 10 and 18. It works really well and uses the same principal as your method, but is not as scientific since it's more subjective. I would be curious to accurately weigh my eggs and see how closely my numbers compare to yours - I'm at 2200 ft in a dry climate.

 

[LA~Poulet]

Wow, thank you for the informative post, and your hatch rate is inspiring!

Living in super humid southern Louisiana, I am contemplating doing more of a dry type hatch. Testing my empty 'bator, I'm getting readings of 20% with nothing added, and when I misted it with a sprayer this a.m. my humidity shot up to 86% and is now at 75%. The person who gave us the incubator lives nearby & used it without adding sponge, only would barely mist the eggs when he hand turned them, and he claims that it was rare for him to have a less than 90% hatch.

Keeping it indoors however, won't our central a/c dry out the air inside? I believe he had it in an outside shop.

 

[LA~Poulet]

I forgot to ask my question! Do you experience a better hatch rate when they come out of the cartons vs. laying on their sides? Can that be done in a still-air inc?