Pullet eggs: male female ratio

Discussion in 'Incubating & Hatching Eggs' started by Tamara119, Oct 22, 2013.

  1. Tamara119

    Tamara119 Chillin' With My Peeps

    188
    41
    103
    Jul 14, 2012
    Bariloche, Patagonia
    Hi all
    I've read a few times now that pullets produce a high number of roosters. So, I'd like to explore this a bit with any of you that know the reasoning and/or science behind this. Is it true that pullets produce more roosters? If so, I can think of three routes to the skewed ratio.
    1. It could be the rooster, i.e., a first year rooster produces more/hardier Y sperm. Obviously, if the pullets are with an older rooster then this isn't a factor.
    2. The sperm are subject to an environment that favours Y sperm, i.e., the pullet's acid/alkaline balance is hindering X sperm and helping Y sperm.
    or,
    3. The ratio of X and Y sperm is normal, but the pullet's body temp during incubation is the factor. Obviously, the eggs are decidedly male or female already, but I've read that male embryos are more likely to survive slightly higher temps while female embryos are more likely to survive slightly lower temps. In this case, if the pullets are incubating at a higher-than-normal temp, then the female eggs have higher mortality, so a clutch of 10 eggs may have 5 roos, 1 female, and 4 dead (females) for example.

    What do you think? I'm planning on hatching some of my BCM eggs as soon as she's laying, and I'd like to know if there's any truth to the skew towards male offspring.

    Thanks!
    Tamara
     
  2. cmfarm

    cmfarm Chillin' With My Peeps

    1,100
    14
    161
    May 3, 2010
    Elgin, TX
    I haven't hear anything about age of a chicken having to do anything what gender chick they hatch.
     
  3. Wyandottes7

    Wyandottes7 Overrun With Chickens

    20,569
    1,158
    391
    Jul 24, 2013
    I've heard the opposite, that pullets often produce more pullets than cockerels. I personally don't think that this is true.
     
  4. Tamara119

    Tamara119 Chillin' With My Peeps

    188
    41
    103
    Jul 14, 2012
    Bariloche, Patagonia
    Interesting. So if it's just a myth, that's good!
     
  5. Hanna8

    Hanna8 Chillin' With My Peeps

    177
    11
    91
    Jan 26, 2012
    As for what you said about the rooster producing more X or Y chromosomes- with chickens, it's actually the hen's genes that determine sex. Chicken sex is determined by Z and W chromosomes. Roosters have ZZ and hens have ZW.
     
  6. Tamara119

    Tamara119 Chillin' With My Peeps

    188
    41
    103
    Jul 14, 2012
    Bariloche, Patagonia
    Oh, whoops! I forgot they are ZW sex-determinates!
     

BackYard Chickens is proudly sponsored by