temperature and sex determination

Discussion in 'Incubating & Hatching Eggs' started by michickie, May 21, 2012.

  1. michickie

    michickie Hatching

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    In mamals ....the sex is determined by how fast the male or female sperm get to the egg.
    natures way of keeping the sexes almost equal...
    so it would stand to reason that a hen of any bird species...if the food and weather are good a large clutch would be hard to keep warm since the large number of eggs in the nest would be closer to the exterior of the nest...a few degrees cooler and produce more males...on the other had if a hen had only a few eggs..meaning her mate or other hardship circumstances ...such as lack of food or less males to protect her...she would have fewer eggs ....the temperature would be warmer since they were directly under her most of the time...this would produce more females since the number of eggs is less meaning less females in the world would threaten their future exhistance...!!!
    Nature has a way of keeping the balance...EX...crocodile eggs will be more male or female if the mound temperature is different it should apply to any egg chicken or reptile...ya think?
     
  2. Hi Michickie WELCOME to the forum..............

    I did a bing.com query on this subject...and the expert advice turned up from posts in BYC......;O)

    https://www.backyardchickens.com/t/270820/does-temperature-of-incubator-determine-sex-of-chicken
    https://www.backyardchickens.com/t/...erature-affect-sex-of-developing-chick-embryo
    https://www.backyardchickens.com/t/237217/about-incubation-temperature-and-chick-gender-anyone

    and one more from the search
    http://wiki.answers.com/Q/Can_incubating_chickens_at_a_certain_temparatue_determine_sex

    As someone said, if it were possible, hatcheries that supply the egg industry would probably have it figured out by now.
     
  3. Nsampsel

    Nsampsel Songster

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    Chicken eggs are fertilized before they are laid & sex is already determined...by the male...just as it is in humans, apes, cats, dogs, horses, cows, and most other warm blooded animals. Sex is based on inherited genetic material.

    Amphibians & reptiles often fertilize eggs EXTERNALLY. And with them being cold blooded, temps definitely have an affect on sex. In some reptiles & amphibians, the temp actually determines the sex because it releases a chemical at a certain temp that then determines the gender of the baby.
     
    Last edited: May 22, 2012
  4. Ridgerunner

    Ridgerunner Free Ranging

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    Sex is determined before the egg is fertilized. It's the hen that determines if the egg would produce a male or female, not the rooster. If the hen supplies two full sets of genes to the ovum, it will produce a male if hatched. If she withholds the sex-linked genes, then it will produce a female. The basis for making sex links is that the hen determines the sex of the chick by which set of genes she provides.
     
  5. Nsampsel

    Nsampsel Songster

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    THANKS!!! Didn't realize it was the hen, just knew it was determined before the egg was laid [​IMG]
     
  6. dretd

    dretd Songster

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    To clarify, chickens use chromosomes to determine sex but they use a ZW system like the XY/XX in humans (with the XY=boy and XX=girl), only it is the opposite so that the hens have the odd pair ZW and the Roos have the same pair ZZ,

    Each parent always contributes one of their 2 chromosomes to the chick. The hen will contribute a Z or a W and the roo contributes a Z or a Z (since Z's are all he has). If the chick gets the W then it will be a girl and if the chick gets the Z it will be a boy (ZW=girl, ZZ=boy). This fertilization occurs before the shell goes on inside the chicken, so sex is determined before the egg is layed.

    In the case of black sex links for instance, the sex-linkage is through color so you can tell the difference in the color between the boys and girls at hatch. The barring from the female is on the Z (she has WZ) and gets carried over to the boy since he gets her Z, but not to the girl chicks since they get her W. The roo is ZZ, but he is unbarred so there is no bar color from him since he doesn't have one to give. Only the boys who inherited the Z from the hen are barred thus you can tell the difference at hatch.
     
    Last edited: May 22, 2012
  7. Nsampsel

    Nsampsel Songster

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    Cool [​IMG]
     

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