Air sac determines sex.

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I recently read a booklet by Thomas Quisenberry that was titled How to Tell The Sex of an Egg Before Incubation. In the book it described candling a chicken egg prior to incubation. If the air sac is off center and can only be viewed from the front and sides of the egg, a female will hatch. If the air sac is centered in the end and can be viewed from all sides, a male will hatch. This was proved in a University study. Mrs. Noda Fry was the person who reported this method to Mr. Quisenberry. She hatched 96 eggs and 92 were female. She also described holding a chick by the head. If the legs relax and hang, this is a cockerel. If the legs draw up toward the head/abdomen, this is a female.
Has anyone else ever tried this? I am about to put a couple dozen eggs in the incubator that I have candled using this method.
Did your method work? I'm going to set my incubator this weekend.
 
Super cool @Boop2006 . I read that booklet over 5 years ago but had forgotten about it. I think it’s great to try things like this. Without experiments, we don’t learn.

I have always kind of wondered about the logic that “there can’t be any way to sex chicks early because if there was the hatcheries would have done it already.” Hatcheries do use their male chicks. They grind them up for dog food. They sell them as cockerels. They keep some for breeding future generations. I honestly don’t think that they have very much “motive” to change their methods. It takes nearly no time for them to vent sex chicks. Even if there are methods like this that could possibly work most of the time but could have a bigger margin of error (say 80% instead of the 90% vent sexing error) I think they wouldn’t think it worth their time to switch.

All just my own thoughts and opinions - which could be dead wrong - and people can think I’m dumb for thinking so, it doesn’t bother me! I personally just think it’s fun to do experiments like this, and I love when people do them and end up sharing results!! I am going to try and remember to do this on my next hatch!
 
Super cool @Boop2006 . I read that booklet over 5 years ago but had forgotten about it. I think it’s great to try things like this. Without experiments, we don’t learn.

I have always kind of wondered about the logic that “there can’t be any way to sex chicks early because if there was the hatcheries would have done it already.” Hatcheries do use their male chicks. They grind them up for dog food. They sell them as cockerels. They keep some for breeding future generations. I honestly don’t think that they have very much “motive” to change their methods. It takes nearly no time for them to vent sex chicks. Even if there are methods like this that could possibly work most of the time but could have a bigger margin of error (say 80% instead of the 90% vent sexing error) I think they wouldn’t think it worth their time to switch.

All just my own thoughts and opinions - which could be dead wrong - and people can think I’m dumb for thinking so, it doesn’t bother me! I personally just think it’s fun to do experiments like this, and I love when people do them and end up sharing results!! I am going to try and remember to do this on my next hatch!
Hatcheries are actually trying to develop ways to sex chicks while they're still in the egg due to pressure to phase out chick culling. In fact I think it's set to be outlawed in some places in the coming years so they very much do have a vested interest in sexing chicks while in the egg
 
Hatcheries are actually trying to develop ways to sex chicks while they're still in the egg due to pressure to phase out chick culling. In fact I think it's set to be outlawed in some places in the coming years so they very much do have a vested interest in sexing chicks while in the egg
Interesting, well that would make sense! So are they constantly doing experiments? Don’t you think that even if they did find a way, they would never disclose it? Why would they want the public/other hatcheries/etc knowing how to figure out gender early?
 
Interesting, well that would make sense! So are they constantly doing experiments? Don’t you think that even if they did find a way, they would never disclose it? Why would they want the public/other hatcheries/etc knowing how to figure out gender early?
Actually there are already a few methods in the works, however none of them would be usable by the backyard keeper as they do require fancy machines. If there was a cheap way to do that rather than buying big expensive machines they would already be doing it
 
Speaking about Air Cells. Here's a Double.
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Name it Hermie if it hatches. Although Mrs. Noda Fry said eggs without air cells won’t hatch. Wonder what 2 air cells would do, 2 headed dragon?
 
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The book was published in 1921. Women had just won the right to vote the year prior. Mrs. Noda Fry wasn’t able to get Mr. Thomas Quisenberry’s attention until after she sent him some chicks. It’s like in May when I was in Mexico for my cousin’s wedding- while some men were very nice, some were rude and I wonder if it had to do with the fact that Claudia Sheinbaum was going to be president. Canada’s only female president Kim Campbell lasted only 3 months. There is growing support for female leadership but the world was more sexist back then. Pardon the pun.

Also I think the oldest hatchery that I know of in the US is McMurray which opened in 1917. Maybe they were just too busy being successful to notice 4 years later and the other hatcheries copied their practices. I’ve read that the hatcheries sometimes work together nowadays, they might have back then as well. Also why sell an egg for 25 cents each when you can get more selling straight run. Then the depression started in 1929 and maybe that info just got lost until here we are about 100 years later when copyright expired. Thank you, Boop!

Ironic that chickens are the opposite of humans when it comes to gender determination and this is the symbol for male:

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Turn the female symbol upside down and the top would be centered like a cockerel egg.

I have 6 eggs in the incubator. 2 might be male. One because it was the roundest egg I have at a shape index of 77, but it has a centered air cell. The other has a SI of 73 and the air cell looked slightly off centre but now is looking more like a cockerel. But it’s on the 3rd day of incubation and I can’t bring myself to toss it so we will see if I end up with 2 cockerels and 4 pullets.

Yesterday was a particularly cold day and the only 4 eggs I collected all have side air cells. This brings the total side air cells to 9 eggs out of 25. Although one of the 25 has no air cell and one has one I can barely see. It says in the book a young cockerel will produce more cockerels with less hens while an old rooster more pullets with more hens. We had 2 cockerels aged 7 months with 8 hens. Hens determine the sex of the egg but maybe epigenetics also have to do with it. I digress. Back to the argument on temperature this is another anectodal account but I hatched 5 serama chicks early April 2023. One was a rooster and 4 hens. Mrs. Fry also wrote that cockerels are the first to hatch. He was the second to hatch and the first hatched a whole day prior. Priscilla was special. Anyway the year before that I bought 11 lemon blue OEGB from Performance Poultry in April as well. After 2 died I had 8 pullets and 1 cockerel. Also in 2023 I ordered 13 fawn silver duckwing OEGB from the same place (sourced from Ideal Poultry). One died but I ended up with 6 cockerels and 6 pullets which I thought would be so based on the pullets’ darker eyeliner. These ones we bought mid May. I also bought sexed chicks in June and in July and each time there was at least one cockerel. First it was 7 chicks with a cockerel late May then 2 chicks June 3 with one a cockerel then 16 chicks July 17 - the only surviving 6 I had one buttercup be a cockerel. 2 of them one was a free cockerel and the other I rehomed with him so he had a friend. Yes it’s all anecdotal but once it’s able to be repeated with more testimonies it becomes fact or at least saves a lot of cockerel’s lives and heartache for some of us who can’t keep roosters but don’t want them to be killed. I do find comfort in knowing that for each cockerel that is home raised it is one less cockerel killed by the big corporations with cramped slaughterhouses.
 
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Mrs. Fry also wrote that cockerels are the first to hatch.
Years ago, I hatched one batch of sexlinks.
Since I could tell males from females by color as they hatched, I found it quite interesting that a bunch of pullet hatched first, then a few each of cockerels and pullets, then the slowpokes were all cockerels.

I have no idea if this was a one-time oddity or if the pattern would hold true for bigger experiments. I haven't been in a position to test it more since then.

I don't remember exactly how many chicks were involved, except that it was a relatively large group for me at the time (so I'd say more than a dozen chicks, but probably less than two dozen.)

The book was published in 1921....
Also I think the oldest hatchery that I know of in the US is McMurray which opened in 1917. Maybe they were just too busy being successful to notice 4 years later and the other hatcheries copied their practices. I’ve read that the hatcheries sometimes work together nowadays, they might have back then as well. Also why sell an egg for 25 cents each when you can get more selling straight run. Then the depression started in 1929 and maybe that info just got lost until here we are about 100 years later when copyright expired.
Maybe it was ignored. Or maybe it doesn't work.

I have 6 eggs in the incubator. 2 might be male. One because it was the roundest egg I have at a shape index of 77, but it has a centered air cell. The other has a SI of 73 and the air cell looked slightly off centre but now is looking more like a cockerel. But it’s on the 3rd day of incubation and I can’t bring myself to toss it so we will see if I end up with 2 cockerels and 4 pullets.
I'll be curious to hear what you discover from the eggs you are incubating.
Do you intend to keep track of which chicks come from which eggs, or just the total count of males and females? Getting two males and four females from six eggs would not be particularly surprising, if you can't show which ones came from where.
 

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