Refrigerated eggs experiment complete!

[NatJ]

Is the production of M/F genetically predisposed? I wonder if, cumulatively the stats would be 50/50, but isolated hens (or people for that matter) would produce M/F more frequently.

Does this question make sense or am I being too vague?

I've read that most hens, and most flocks overall, produce equal numbers, but that some hens do produce more offspring of one gender than the other.

I have not read how common such hens are, but they must be fairly rare, or we would all know about them.

For a hen that produces mostly daughters, do her daughters do the same? I'd love to know, but if it has been studied, I have not been able to find it.

I don’t know that this has anything to do with determining gender of poultry chicks, however reptile eggs (alligator, crocs, turtles) gender is in fact affected by incubation temperatures. Since chickens are evolutionary cousins of crocs (and dinosaurs!) that’s something to study on. Experiments need to be repeated multiple times with exact conditions (and control group) before results can be verified.

Chickens definitely have sex chromosomes, ZZ for male and ZW for female.
We know this determines the gender, because there are several useful genes on the Z chromosome. They are used to produce sex-link chicks, where the two sexes are different colors. When the father has the recessive gene, and the mother has the dominant gene, then the daughters show the recessive gene while the sons show the dominant gene but also carry the recessive gene. This works so reliably (millions of chicks per year!) that we know there is no other sex-determination mechanism commonly affecting chickens.

Also, a temperature-dependent system would not be very useful to a creature that incubates the eggs, because the eggs always do get incubated at the right temperature in nature.

So even though crocodiles are interesting relatives, chickens don't work that way.

People have experimented with whether higher or lower incubation temperatures would selectively kill one sex of chick, but so far it appears that both sexes die at about the same temperatures, so it's not useful at the backyard or commercial scale.

 

[Victinag]

• My silkie recently went broody. She was sitting on 5 fresh eggs and I pulled 10 of her eggs out of the fridge,marked them, and put them under her. 5 of the fridge eggs had been in the fridge for at least 2 weeks- And 5 for at least a week. Candeling on day 12 showed 13 developing eggs. They started hatching on day 21( 1/26/21) and the last hatched thursday(1/28) we had to help that last one just a little bit. Unfortunately,there were still 2 unhatched eggs Further inspection showed no signs of life, so we waited a bit longer, checked again then discarded them so, out of 15 eggs, 11 hatched. The last one is a little wimpy, but we've got him inside and are keeping him warm and feeding electrolyte water with a dropped. The other 10 are thriving and doing so well!

 

[Orpingtons Mom]

I've read that most hens, and most flocks overall, produce equal numbers, but that some hens do produce more offspring of one gender than the other.

@ConnieA... we’ll have to enroll you in a study!

Also, if I remember my high school biology, I think it’s the male that determines the sex. Hmmmm. Now, ConnieA, did both hens have the same roo for their clutches?

 

[NatJ]

Also, if I remember my high school biology, I think it’s the male that determines the sex. Hmmmm. Now, ConnieA, did both hens have the same roo for their clutches?

In people and other mammals, yes.
But chickens and other birds do it backwards, so the hen does determine the sex of her chicks.
https://en.wikipedia.org/wiki/ZW_sex-determination_system

 

[Foxinthehenhouse]

Ok, so about a month ago I was asking if using high temperatures to hatch out eggs would produce more females (because it would basically kill the male eggs).
The discussion led to many responses, and one that came up was from a member who says they only hatch out refrigerated eggs, and they do this to get more females, less males. So, having an abundance of eggs I thought I would try it. I set 21 eggs. Almost all started to develop... (candling is hard with dark and blue eggs) but in the end, I only had one chick hatch...so maybe not something I will try again. LOL. However, it is a very robust little chick. I am looking for better names then its current one... "FRIDGE"
I will let you know if it turns out female.

Uno for its name.

 

[joydix]

Ok, so about a month ago I was asking if using high temperatures to hatch out eggs would produce more females (because it would basically kill the male eggs).
The discussion led to many responses, and one that came up was from a member who says they only hatch out refrigerated eggs, and they do this to get more females, less males. So, having an abundance of eggs I thought I would try it. I set 21 eggs. Almost all started to develop... (candling is hard with dark and blue eggs) but in the end, I only had one chick hatch...so maybe not something I will try again. LOL. However, it is a very robust little chick. I am looking for better names then its current one... "FRIDGE"
I will let you know if it turns out female.

Question: did you also use hi heat and what temp? What are your ideas on why only 1 when they were all developing?

 

[333113]

@ConnieA... we’ll have to enroll you in a study!

Also, if I remember my high school biology, I think it’s the male that determines the sex. Hmmmm. Now, ConnieA, did both hens have the same roo for their clutches?

Not the same roo for both clutches, but that doesn't matter, because the hen's genetic contribution determines the sex of the chicks.

 

[Curnow]

Ok, so about a month ago I was asking if using high temperatures to hatch out eggs would produce more females (because it would basically kill the male eggs).
The discussion led to many responses, and one that came up was from a member who says they only hatch out refrigerated eggs, and they do this to get more females, less males. So, having an abundance of eggs I thought I would try it. I set 21 eggs. Almost all started to develop... (candling is hard with dark and blue eggs) but in the end, I only had one chick hatch...so maybe not something I will try again. LOL. However, it is a very robust little chick. I am looking for better names then its current one... "FRIDGE"
I will let you know if it turns out female.

I like the name "Fridge". There was a famous football player, a lineman I think, that was called "The Refrigerator". His real name was William Perry. Maybe call the chick Perry if Fridge isn't pleasing. Tough chick....tough football player!!

 

[Lcoffin]

We bought 14 eggs that had gotten chilled sitting out at around 45 degrees Fahrenheit. 4 never started to develop, 4 began developing but didn't make it, and 6 survived to hatching (and continue to thrive, almost one year later!) We ultimately ended up with four girls and two boys.

 

[Debbi H]

Ok, so about a month ago I was asking if using high temperatures to hatch out eggs would produce more females (because it would basically kill the male eggs).
The discussion led to many responses, and one that came up was from a member who says they only hatch out refrigerated eggs, and they do this to get more females, less males. So, having an abundance of eggs I thought I would try it. I set 21 eggs. Almost all started to develop... (candling is hard with dark and blue eggs) but in the end, I only had one chick hatch...so maybe not something I will try again. LOL. However, it is a very robust little chick. I am looking for better names then its current one... "FRIDGE"
I will let you know if it turns out female.

I didn't even know you could hatch eggs after being refrigerated until a couple months ago when I heard it here! Now I'm hearing you say that temperature can change whether an egg produces a female or male chick? Maybe I didn't know this stuff because I've only always bought chicks already hatched and put them under my broody hens in the middle of the night (they wake up the next morning so proud to be mamas).
Looking forward to hearing what the sex of "Fridge" turns out to be...and what you change the name to!