Does Lowering The Incubators Temperature Kill The Male Embryos?

[MysteryChicken]

How?

If a male embryo has ZZ sex chromosomes, I do not see any way refrigerating it can make the chromosomes become ZW. Cold temperature is not going to add something that was not there before (W chromosome.)

(And yes, it is very clear that chicken gender is determined by the chromosomes. All those sexlink hybrids are based on it, and they are so common we know it works.)


That's great! But if you have no dead embryos, it means you are not doing anything that kills male embryos.

I learned the refrigeration method from an actual scientific study, & have been using it since. According to the study, the female chicks are genetically Male, & when bred to a rooster they will produce only males.

I think the eggs were only refrigerated for a few days before incubation though.

 

[The Moonshiner]

I learned the refrigeration method from an actual scientific study, & have been using it since. According to the study, the female chicks are genetically Male, & when bred to a rooster they will produce only males.

I think the eggs were only refrigerated for a few days before incubation though.

 

[The Moonshiner]

Let me try to follow that since I've now read it like 37 times.
So females are really males and when bred to males only produce males?
Interesting.

 

[NatJ]

I learned the refrigeration method from an actual scientific study, & have been using it since. According to the study, the female chicks are genetically Male, & when bred to a rooster will produce only males.

That mechanism might work.

But if you sell any of those "females" to someone, they may be pretty disappointed when they hatch some eggs and every chick is male!

Have you tested any of them to see if this is actually what is happening with your birds?
(Either DNA sex test on the "females" showing them to be male, or batches of all-male chicks from "females" that you hatched that way.)

 

[NatJ]

Let me try to follow that since I've now read it like 37 times.
So females are really males and when bred to males only produce males?
Interesting.

I think it works out to birds that are genetically males, but look and act like females (even to the extent of producing eggs that can hatch.)

But being genetically ZZ, they can only produce male chicks-- because a normal female gets her W chromosome from her mother. And these "mothers" have no W chromosome to give.

I suppose if this worked well enough, and you were willing to refrigerate eggs for every hatch, you could develop a "breed" that is genetically all male

 

[The Moonshiner]

But I thought this thread and the cooler temp idea was about not producing males.
Which she was just posting about it working. Now it's turned to producing males that are males and males that are females and breeding males to males and producing all males.
This train has jumped the tracks and crashed into an alternate world where's there's no real females.
My head hurts. I'm crawling from this wreckage back to my simple world.

 

[MysteryChicken]

That mechanism might work.

But if you sell any of those "females" to someone, they may be pretty disappointed when they hatch some eggs and every chick is male!

Have you tested any of them to see if this is actually what is happening with your birds?
(Either DNA sex test on the "females" showing them to be male, or batches of all-male chicks from "females" that you hatched that way.)

I have tested with breeding my Porcelain D'uccles. I hatched 1 pullet from refrigerated eggs a couple years ago, bred her back to her father this year, took 6 of her eggs, put them in the incubator, 4 hatched out male, the other two failed to develop.

I can DNA Sex test them maybe next year if possible. Majority of the original birds are getting butchered, so it'll have to be a new batch to be tested.

 

[Silexian]

One would think that if this was true or possible. That it would already be common practice amongst the commercial egg farms and hatcheries.

 

[LadiesAndJane]

One would think that if this was true or possible. That it would already be common practice amongst the commercial egg farms and hatcheries.

Agreed.

 

[NatJ]

One would think that if this was true or possible. That it would already be common practice amongst the commercial egg farms and hatcheries.

There are plenty of possible things that are still not practical.

In this case, I think some studies have found some difference in the ratio of male and female chicks when they mess with the temperature-- but not enough to be useful in a commercial setting.