Consistently hatching more males than females

[SourRoses]

but what's the genetic basis for it? Just like you can get say, 4 heads in a row (or 4 tails), so you could get 4 boys (or girls). How could it work at a genetic level?

@NatJ provided some great info.

The hens individual ova are either Z (male) or W (female).
Theoretically, the ratio of male to female depends on the genes of her parents influencing certain hormone levels during her development (and therefore the development of her ova, since hens are born with their eggs).

There is some interesting research around the Z-linked gene DMRT1 - Sex determination and gonadal sex differentiation in the chicken model
If I'm reading it correctly (highly debatable), it would seem to indicate that hens inherit this hormone (progesterone / ?) influencing gene from their fathers. And can pass it on to their sons but can't pass it on to their daughters.


For the OP, since hatching out so many males is very problematic, it might be a good idea to avoid hatching from these hens again. Their sons also should probably not be bred. If you have daughters from them they might be okay to breed, but you'd have to test hatch to know.

Disclaimer: Not an expert, just a reader/repeater

 

[NatJ]

I know that’s what everyone says but then why has it worked every time with chicks hatched from my BCM rooster?
All the chicks that he sired last hatch were slow feathering except for 1 and that 1 chick was the only female.

For feather sexing to work:
--the father must have fast feathering.
--the mother must have slow feathering.

This produces slow-feathering sons and fast-feathering daughters.

If you happen to have a pen where the rooster is fast feathering, and the hens are all slow feathering, then yes you do get feather-sexable chicks.


The genetic basis for that:
Female chickens have chromosomes ZW
Male chickens have chromosomes ZZ
Fast/slow feathering is on the Z chromosome

So a hen will inherit W from her mother (no effect on feathering speed), and Z from her father (determines how fast she grows her feathers.)

A rooster will inherit Z from each parent. If he gets 2 that match (both fast, or both slow), of course he grows feathers at that speed. If he gets one of each, he grows feathers slowly, because slow is dominant.

So a rooster who grew his own feathers fast when he was a chick must have two copies of the fast gene (because it is the recessive, so it only shows when he has two copies of it.) He gives fast feathering to every daughter, so they all feather quickly.

A hen with slow feathering will give that to her sons, and because slow is dominant, all her sons will show slow feathering, not matter what gene they inherit from their father.

 

[PeepingK]

For feather sexing to work:
--the father must have fast feathering.
--the mother must have slow feathering.

This produces slow-feathering sons and fast-feathering daughters.

If you happen to have a pen where the rooster is fast feathering, and the hens are all slow feathering, then yes you do get feather-sexable chicks.


The genetic basis for that:
Female chickens have chromosomes ZW
Male chickens have chromosomes ZZ
Fast/slow feathering is on the Z chromosome

So a hen will inherit W from her mother (no effect on feathering speed), and Z from her father (determines how fast she grows her feathers.)

A rooster will inherit Z from each parent. If he gets 2 that match (both fast, or both slow), of course he grows feathers at that speed. If he gets one of each, he grows feathers slowly, because slow is dominant.

So a rooster who grew his own feathers fast when he was a chick must have two copies of the fast gene (because it is the recessive, so it only shows when he has two copies of it.) He gives fast feathering to every daughter, so they all feather quickly.

A hen with slow feathering will give that to her sons, and because slow is dominant, all her sons will show slow feathering, not matter what gene they inherit from their father.

Wow that’s a very helpful explanation, thank you for that!

So in order for a female chick to be fast feathering her farther must also be fast feathering?
I noticed from a previous hatch that 2 chicks from the same hen and roo, one turned out to be fast feathering and male, and the other turned out to be slow feathering and female. But I know for a fact that the dad feathered in slowly as a chick. So how does this work then? If the dad is slow feathering then wouldn’t that mean that all the females that he sires would be slow feathering as well?
The hen that laid those 2 eggs feathered in fast as a chick.
I had a couple Easter egger hens in a pen with the same roo that hatched fast feathering chicks and they all turned out male. Which would mean that both mom and dad would both had to have had the fast feathering gene right?

Sorry I don’t know why I’m having such a hard time understanding this lol.

 

[NatJ]

So in order for a female chick to be fast feathering her farther must also be fast feathering?
I noticed from a previous hatch that 2 chicks from the same hen and roo, one turned out to be fast feathering and male, and the other turned out to be slow feathering and female. But I know for a fact that the dad feathered in slowly as a chick. So how does this work then? If the dad is slow feathering then wouldn’t that mean that all the females that he sires would be slow feathering as well?

Your rooster has the genes for both fast feathering and slow feathering.
Because slow feathering is dominant, he grew his feathers slowly. But because he also has the gene for fast feathering, some of his chicks will inherit that from him.

He can give either gene to any of his chicks. In this particular case, the daughter got slow feathering. And the son inherited fast feathering from both parents, and thus he grew feathers quickly.

The hen that laid those 2 eggs feathered in fast as a chick.

So she would give fast feathering to her son, and the father must have given him fast feathering as well, so that son was able to grow his feathers fast. That son is pure for fast feathering.

I had a couple Easter egger hens in a pen with the same roo that hatched fast feathering chicks and they all turned out male. Which would mean that both mom and dad would both had to have had the fast feathering gene right?

Yes. Those hens must have fast feathering (on their only Z chromosome), and the sons inherited fast feathering from their dad as well. It's just a coincidence that all those sons inherited fast feathering, when the father could have given them either fast or slow.

Sorry I don’t know why I’m having such a hard time understanding this lol.

It definitely can be confusing. When I was first learning about this, it took me quite a few tries get it straight

 

[PeepingK]

Your rooster has the genes for both fast feathering and slow feathering.
Because slow feathering is dominant, he grew his feathers slowly. But because he also has the gene for fast feathering, some of his chicks will inherit that from him.

He can give either gene to any of his chicks. In this particular case, the daughter got slow feathering. And the son inherited fast feathering from both parents, and thus he grew feathers quickly.


So she would give fast feathering to her son, and the father must have given him fast feathering as well, so that son was able to grow his feathers fast. That son is pure for fast feathering.


Yes. Those hens must have fast feathering (on their only Z chromosome), and the sons inherited fast feathering from their dad as well. It's just a coincidence that all those sons inherited fast feathering, when the father could have given them either fast or slow.


It definitely can be confusing. When I was first learning about this, it took me quite a few tries get it straight

Thank you so much for taking the time to explain this to me, I really appreciate it!!

Last question! Now I have 10, 2-3 day old chicks (the ones I mentioned earlier in the thread) from 2 different hens and their pin feathers are looking like they will be slow feathering. So there’s a possibility that these chicks could be male or female?
The rooster that sired these chicks is different than the one that I was mentioning earlier. He’s the one that fathered all the chicks that turned out to be male (the ones given to the family with kids).
Thank again for helping me understand!

 

[NatJ]

Last question! Now I have 10, 2-3 day old chicks (the ones I mentioned earlier in the thread) from 2 different hens and their pin feathers are looking like they will be slow feathering. So there’s a possibility that these chicks could be male or female?
The rooster that sired these chicks is different than the one that I was mentioning earlier. He’s the one that fathered all the chicks that turned out to be male (the ones given to the family with kids).

I've lost track: do you know the feathering speed of this rooster? If you do not know, then you should assume the chicks could be either gender.

If you know the father of these chicks has the slow feathering gene (grew his own feathers slowly), then the chicks definitely could be either gender.

But if the father grew his own feathers quickly, then any of his chicks that are slow feathering would have to be male. Because fast feathering is recessive, a male chicken will only grow his feathers fast if he as two copies of the gene, which means fast feathering is the only form he can give his chicks. So if the father is fast feathering, and his chick is slow feathering, that means the chick inherited slow feathering from the mother-- and only male chicks can inherit feathering speed from their mother. (Because the daughters inherit a W chromosome from their mother, that makes them female but has no effect on feathering speed.)

If you know the feathering speed of the mothers but not the father, it might also be possible to figure out whether feather-sexing could work on those chicks.

 

[Poultrybonkers]

Feather sexong osnt always acutate either ive had slow feathering females and fast feathering males. That only works if you breed a fast feathering gene to a slow feathering gene

 

[NatJ]

Feather sexong osnt always acutate either ive had slow feathering females and fast feathering males. That only works if you breed a fast feathering gene to a slow feathering gene

Yes, that's what we've been talking about for the last page or so: when it works and when it does not work.

Short version:
When the father is pure for fast feathering (2 copies of the gene), and the mother has slow feathering (1 copy of the gene, on the only Z chromosome she has), it works. Any other arrangement will produce chicks that cannot be feather sexed.

 

[PeepingK]

I've lost track: do you know the feathering speed of this rooster? If you do not know, then you should assume the chicks could be either gender.

If you know the father of these chicks has the slow feathering gene (grew his own feathers slowly), then the chicks definitely could be either gender.

But if the father grew his own feathers quickly, then any of his chicks that are slow feathering would have to be male. Because fast feathering is recessive, a male chicken will only grow his feathers fast if he as two copies of the gene, which means fast feathering is the only form he can give his chicks. So if the father is fast feathering, and his chick is slow feathering, that means the chick inherited slow feathering from the mother-- and only male chicks can inherit feathering speed from their mother. (Because the daughters inherit a W chromosome from their mother, that makes them female but has no effect on feathering speed.)

If you know the feathering speed of the mothers but not the father, it might also be possible to figure out whether feather-sexing could work on those chicks.

I think I’m finally starting to get it lol

I don’t know what genes the rooster has or his hens… so I guess I’ll just have to wait and see what gender the chicks are, I’m really excited to see if my guesses will be right! Genetics fascinate me!

Thanks for all your help!

 

[Poultrybonkers]

I think I’m finally starting to get it lol

I don’t know what genes the rooster has or his hens… so I guess I’ll just have to wait and see what gender the chicks are, I’m really excited to see if my guesses will be right! Genetics fascinate me!

Thanks for all your help!

If your testing things you should test fridgerated eggs to see if more females will hatch...its what ive heard before lol