I have a bone to pick with all you incubating ppl...

[JacinLarkwell]

Check your temps... too high a temp and you'll get more cockerels than pullets. It may only be a decimal point or two, but it's enough. Try to keep it at the 99.5 but no lower than 99.2 for more pullets.

That's for certain reptiles. Not birds

 

[JacinLarkwell]

How is the sex determined in chicken fertilization? Is the trigger chromosomal as in higher orders, or is it an environmental trigger such as temperature, humidity or a combination of factors independent of the genetic contributions of the parent birds?

Male passes a Z chromosome, and females pass either a Z or W chromosome. Same thing a mammals, but opposite genders

 

[Coops Dad]

Temp affects the gender of some reptiles. If it was as simple as raising or lowering the temp for chickens, hatcheries wouldn't throw away so many cockerels or put accidental cockerels in oullet orders. They would capitalize on that and run with it.

In birds, sex is determined by the female within her ova.

I love science and facts. Thanks!

I would consider tracking the offspring of my hens to weight our hatch's results, the way Henry VIII's prospective wives should've done, but that's a lot of works and I'm filled to the brim with laziness.

 

[Painted Calls]

I love science and facts. Thanks!

Me too!

 

[JacinLarkwell]

I love science and facts. Thanks!

I would consider tracking the offspring of my hens to weight our hatch's results, the way Henry VIII's prospective wives should've done, but that's a lot of works and I'm filled to the brim with laziness.

That's what I (kinda) did. I had a female pheonix that was always very pullet heavy in her hatches. I think out of 30 plus chicks that made it past the 4 weeks necessary for.mine, only 3 or 4 developed male signals. Too bad I had to rehome her because of her nesting sites

 

[JacinLarkwell]

Perhaps I'll do a test (as well as I can with my setup) later next spring while I'm incubating

 

[The Ranch Girl]

Its nust part of life, Sorry no one warned you. Chicks in eggs are just to darn addicting.

 

[Liz Birdlover]

This literally just occurred to me as I read this exchange. I understand the science regarding what determines the sex of humans and other mammals but am now on the fence with chickens. Theoretically, in animals that carry gender-determining chromosomes in their gametes, gender is determined the moment the egg is fertilized, correct? But the American Alligator can tip the scales to heavily favor one sex or the other by piling compost on the nest mounds to create either a higher than average temperature in the egg clutch or lower than average temp.

How is the sex determined in chicken fertilization? Is the trigger chromosomal as in higher orders, or is it an environmental trigger such as temperature, humidity or a combination of factors independent of the genetic contributions of the parent birds?

Interesting topic!
We humans don't know everything that occurs in nature...Still have a lot to learn. I've seen writings both pro & con on these subjects.

https://www.fresheggsdaily.blog/2016/04/the-secret-to-hatching-hens-not-roosters.html

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1629050/

https://theconversation.com/how-birds-become-male-or-female-and-occasionally-both-112061

https://www.audubon.org/news/newly-recorded-condor-virgin-birth-another-way-birds-are-reptiles

 

[Hip Hillbilly Acres]

Perhaps I'll do a test (as well as I can with my setup) later next spring while I'm incubating

Please DO. Start a thread so we can all keep up. I'd for one would be interested.

 

[Hip Hillbilly Acres]

After I get this brood down pat I suspect I'll be the next "unsuspecting hatching addict" only controlled by lack of coop space . . . . What fun a career would be to hatch chicks for people. Hmmm, could there be a need for such a person?