Humidity Question **warning probably stupid**

Discussion in 'Incubating & Hatching Eggs' started by Oven Ready, Jul 20, 2010.

  1. Oven Ready

    Oven Ready Chillin' With My Peeps

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    I see a lot of people who use incubators advising to keep humidity down at 30-50 and then only up to 60-70 in the last few days.

    I don't use an incubator, I use chickens but our humidity levels, pretty much year round, are about 80-90% in the morning dropping off to 60-70% in the afternoon.
    Our temperatures range from 30C in the morning to 37C by midday most days, somedays up to and over 40C.

    Can my little old chooks really regulate the humidity so much? The temperature I can understand because even 40C isn't as hot as a chicken but how exactly do they manage to reduce the ambient humidity by half (all day long) ?

    I did warn you it may be a stupid question.
     
  2. scbatz33

    scbatz33 No Vacancy, Belfry Full

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    Actually, that is a darn good question. Any one have an answer?
     
  3. Oven Ready

    Oven Ready Chillin' With My Peeps

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    Any one have an answer?

    It would seem not so I'll try giving a possible answer and then hopefully get shot down in flames with the right answer.

    Often our hens will push one or two, sometimes half a dozen, eggs out from under them and just sit there with these eggs in front of them. Perhaps exposing them to a breeze allows the eggs to evaporate excess moisture - is that a possibility?​
     
  4. iamcuriositycat

    iamcuriositycat Chillin' With My Peeps

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    I don't have a precise answer, but I have some educated "guesses." The first thing to keep in mind is that as soon as we take an egg and place it in an artificial incubator, we no longer have a natural situation. The upshot of that is that we have to do all kinds of "unnatural" things to try and counterbalance the other unnatural things we are doing. For instance, a hen does not turn her eggs precisely once per hour. She does not store them upright. She does not cool them for a specific number of minutes per day and she doesn't monitor the humidity. We do all those things because we've created an artificial situation that needs "fixing."

    In the case of humidity, the problem we are trying to "fix" is that the air cells need to develop at a certain rate, but then the membranes need to not dry out during the hatch, and the shell needs to soften up a little (sometimes). There are many ways to help the air cell develop. Moistening the shell a little each day helps the moisture to evaporate out of the egg through the action of polarity (water attracts water, so water on the outside of the shell attracts water inside and causes it to evaporate faster... I think that's how it works but don't quote me). Lowering humidity causes more moisture to evaporate from inside the egg. Higher temps evaporate moisture better. And so on--I'm sure I'm missing some potential options.

    In an incubator, the simplest thing is to lower the humidity to help the air cell develop. Some people also spritz them with water.

    The hen may use any number of strategies to help the air cell develop, but she does it instinctively. She may air the eggs regularly to let them evaporate better, she may moisten her belly in order to moisten the eggs to help them develop. There may be things she does that no human even understands yet.

    And when it's time for them to hatch, she monitors the humidity to keep them from drying out by staying right on top of them. I haven't hatched under broodies, but I have heard people frequently talk about how the hen becomes "glued" to the nest during the last few days. This has a similar effect to raising humidity--pipping eggs that are not exposed to as much air, won't have a chance to dry out.

    Anyway--none of that is scientific. It's just based on my understanding of how and why humidity is important in an incubator, and the different options a hen may have for accomplishing the same end.

    Hope that helps...
     
  5. nicoletm24

    nicoletm24 Chillin' With My Peeps

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    my father in law hatches with his hens...not a bator and he sill tell us that the hen gets off the eggs 2 times aday, then rolls them when she gets back on. it's like she lets them cool for a period of time, then rotates them, then sits again.

    i dont' have any clue as to the humidity temp...but you'd think with the hens being able to do it naturally, we should have it easier when it came to bators. but we don't.
     
  6. Oven Ready

    Oven Ready Chillin' With My Peeps

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    Thanks for the replies.

    It does seem odd that incubators need to be so precise but hens can hatch eggs in all sorts of weathers without any trouble.

    I've searched the internet without finding much about it, you'd think, given some of the more bizarre things some 'researchers' are paid to research that someone would have figured out how a chicken can hatch eggs in varying climatic conditions.

    If anyone else has any ideas, I'd love to hear them.
     
  7. iamcuriositycat

    iamcuriositycat Chillin' With My Peeps

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    Honestly, as much as we complain about how hard it is to hatch, hens don't necessarily have it so easy either. Depending on the specific hen, her practices, her experience, weather, predators, other birds in the area, location, and much more, a hen can lose eggs or an entire hatch pretty easily, and often does.

    Also, eggs are extremely hardy, even under artificial circumstances. In some parts of the world, duck eggs are incubated using rice bags that are heated in the sun. People have been known to hatch eggs by wearing them in their bra, keeping them under a heat lamp, wrapped in a heating pad, or warmed by kerosene.

    The reason we worry so much over the "ideal" circumstances is that we want the *highest* hatch rate possible. Ideal conditions offer better hatch rates, but many eggs will hatch despite various disasters, poor practices, and general mayhem.

    I'd be really interested to hear a study that shows relative success of artificial vs. natural incubation. I'd be surprised if they weren't pretty close, if you compare a competent hen to an experienced person. I can't do the study myself as my duck hens are TERRIBLE mothers and have yet to hatch a single egg successfully (though I've hatched several that they started and gave up on). So I don't have any idea what it's really like hatching with a good broody. But my artificial incubation yields really good results usually, especially on eggs that I started in the incubator myself versus those that were started under a hen--for some reason, those started under a hen have atrocious hatch rates. But that could just be my crummy broodies! [​IMG]
     
  8. Oven Ready

    Oven Ready Chillin' With My Peeps

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    We have about 70 chickens and over the years our hatch rate is between 60 - 70%. We don't candle for infertile eggs, we don't candle at all - we leave everything to the chickens, all we do is redistribute eggs as some girls like to sit when they only have a few eggs and others will go to 13 or 14 before they sit and then they don't fit over them properly.

    From an earlier topic one poster regularly gets 97% hatch rate using incubators, but that is a commercial business where every failed-to-hatch is lost income.

    From reading this forum it would appear that amatuer (i.e. non-commercial rather than dumb) hatchers using incubators seem to get considerably less than 97% hatch rates, whether this is down to eggs being mailed, amateur incubators not being so precise or whatever I don't know, but there can't be anything much less precise than a chicken who has to deal with hour by hour changes in the weather, yet they manage very well. Like today, the temperature at 3:00pm was dawdling along at 36C, then in about five minutes it had gone up to 41C; it felt like someone had just opened a huge oven in a very small room.

    I know that some of our birds are better 'hatchers' than others, one in particular hatches everything that was fertile, she never misses a single one, it's amazing. Her last clutch of nine eggs, only three were hers, she hatched eight - the ninth was infertile, she is also a good mother to the chicks. We have a broody who has never laid an egg but hatches out other girls eggs but she doesn't look after the chicks, after one or two days she abandons them and goes back to wanting to sit on eggs, fortunately we have enough hens to 'adopt' the abandoned chicks. The rest are all pretty much Mrs Average, they get 6 or 7 from 10 eggs and look after them well enough.

    Maybe, I might start a thread - What hatch rate did you get this time, and over time it'd would show an average. That might also help folks who think they have a low rate, when in fact it's normal.
     
  9. aprophet

    aprophet Chillin' With My Peeps

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    Quote:the first thing I think of is when a duck jumps into the water then crawls back on to the eggs while she is still wet I do not regularly hatch chickens I recently hatched some silkies for my niece had a 100% hatches I thought it may be a fluke but my last coupla quail hatches have been the same with a hovabator no less the more you read , the more you hatch the easier it gets [​IMG]
     
  10. abqferreira

    abqferreira Out Of The Brooder

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    I had wondered about humidity as well. Living in New Mexico, the average humidity is well below 20%. Right now we're in our monsoon season and getting some unusual humidity, but I'm concerned about my banty, who is only on day 4 with her eggs. Will these eggs hatch if the humidity suddenly drops down from about 70% to 11% next week and stays there til they are supposed to hatch? Is there anything I should do if this does happen?
     

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