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Stages of fertilised egg development and how long it can be cold

Discussion in 'Incubating & Hatching Eggs' started by healthyasdotme, Aug 22, 2011.

  1. healthyasdotme

    healthyasdotme In the Brooder

    Hi does anyone explain (or have photos) of the stages of fertilised egg development on each of the days? (like the stages of human baby in the womb)

    Also does anyone know how long a newly hatched fertilised egg can be cold for before it is no good, and then how long that can be as the chick grows inside the egg? I have seen auctions selling fertilised eggs at four days old and these would not be kept warm during transport. I have seen that the eggs also need to be kept warm or the unhatched chick can die so what would be the resilience of more established chicks?

    I am just tryiing to make sense of the development of the chook to hatching. [​IMG] so thank you from a first time chooky mum [​IMG] [​IMG]

  2. Gypsy07

    Gypsy07 Songster

    Feb 4, 2010
    Glasgow, Scotland
    Once a fertile egg has been laid, it SHOULD be kept cool. If it is kept warm, the embryo will start developing, and people don't want that when they buy fertile hatching eggs. Embryos don't start developing until they are heated up, either by an incubator or a broody hen, but keeping them cool is perfectly fine and doesn't damage them at all. Fertile eggs can be stored for quite a long time before being incubated and still produce healthy chicks. Most people like to set eggs that are no older than 7 days, cause fertility is still good after just a week. But some people on BYC have experimented with older eggs; I've had good hatches from eggs that were three weeks old and other people have managed to hatch out eggs that were over a month old.

    All this is so chickens can hatch out all their chicks at the same time. A wild bird or a hen who wants to go broody will lay eggs, one a day or one every second day or whatever, until she has a reasonable sized clutch of eggs. They won't start developing until she sits on them continuously, and she won't do this until she has a good amount of eggs. If all the eggs were to start developing at different times, then they'd all hatch out at different times, and she'd find it difficult to look after new baby chicks at the same time as still sitting on her other eggs.

    Now, once your eggs have started developing they should be kept at a steady 99.5F the whole way through. But just as a broody hen gets off the nest to eat and drink and poop and her eggs will cool down a bit each time she does this, your incubated eggs can undergo a fair bit of fluctuation and still be okay. You'll get the best hatches if you can keep your eggs between 99F and 100F, but between 97F and 102F should give you an okay-ish hatch too. Eggs will hatch after 21 days of incubation, give or take. If your temps are constantly low, you will get a late hatch, and if they are constantly too high, you will get an early one. Temps of above 102F for any sustained length of time will most likely damage or kill your eggs.

    I hope all that info helps you a bit... [​IMG]

    Oh, and hopefully someone can give you a link to photos of embryos developing. It's on here somewhere!
  3. paynemom

    paynemom In the Brooder

    Jan 29, 2008
    Robinson, TX
    Search for "candling eggs". There's a thread with pics of embryo development. I use it to determine if my eggs are developing into chicks. Good luck!
  4. healthyasdotme

    healthyasdotme In the Brooder

    Quote:Wow, that was an awesome reply and information so easy to read and understand, you really have a gift for that! Thanks [​IMG] Love the username [​IMG] I am a gypsy too [​IMG]
  5. ChicKat

    ChicKat Crowing Premium Member

    X2 Thanks Gypsy07-- that answers a lot of questions that I had too!
  6. dancoyben

    dancoyben In the Brooder

    Oct 29, 2014
    new Jersey
    So if my hens are laying fertile eggs and I gather them and store them in the fridge are they OK to eat or will there be any type of blood spot inside or anything else funky that would put off eating or selling them.
  7. WalnutHill

    WalnutHill Crowing

    Mar 16, 2014
    SE Michigan
    If you gather them the day they are laid and refrigerate them, only someone who knows what the blastodisc looks like on a fertile yolk will be able to tell the difference. There is NO difference in the taste or quality of a fertile egg when fresh.

  8. Carpenter Coop

    Carpenter Coop Chirping

    I found my broody hen sitting on other eggs today. The fertile ones were suppose to hatch on the 20th.
    The eggs were cold. I moved her and the eggs where she can't be disturbed.

    Is it too late
    Last edited: Apr 16, 2015
  9. RoxyPuppy

    RoxyPuppy Hatching

    May 23, 2016
    Hey i have fertilized eggs that are 3weeks old, but one of them rolled away from the mom's warm body i found it and hour or 2 later, it was not warm AT ALL. Will the chick be ok?
  10. howfunkyisurchicken

    howfunkyisurchicken Crowing

    Apr 11, 2011
    Most likely, could be a bit delayed. I'd pop it back under her and give it a chance for sure.

    Good luck!

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