There is a study in sexing eggs by shape.

[NatJ]

I would love to do some testing, but my first ever incubator is still on its way.

Hopefully you will have fun and success incubating, and then you can incubate more

 

[Creekchics]

So I came across the same research after hatching four chicks, after checking their shells, it seemed to be true! The elongated shape egg hatched the only male. Can anyone who is hatching eggs please take pictures of eggs and report sex of chicks? I think we could gather more information together that way. These are a picture (not the best angle)of my eggs hatching, the one on right was male, left female, also a couple pictures from the article, left female, right male. I am not planning on hatching very many more eggs, but am facinated by this, and definitely would like to have an 80% accurate prediction next time! I did notice that some of our chickens lay consistently more rounded eggs, I also read some hens yield more female chicks. Any backyard scientists want to contribute? Thanks

Here is the article, it's very technical: https://pmc.ncbi.nlm.nih.gov/articles/PMC9832119/

 

[JacinLarkwell]

It's as accurate as flipping a coin before each hatch. I had several hens that laid torpedo shaped eggs amd had both male and female chicks

 

[tlcmurphy]

In chickens the female determines the sex, so every egg yolk is predetermined as male or female before it’s even laid. There’s absolutely no way the shape of the shell, which comes much later, can determine sex.

 

[No Coop No Problem]

So I came across the same research after hatching four chicks, after checking their shells, it seemed to be true! The elongated shape egg hatched the only male. Can anyone who is hatching eggs please take pictures of eggs and report sex of chicks? I think we could gather more information together that way. These are a picture (not the best angle)of my eggs hatching, the one on right was male, left female, also a couple pictures from the article, left female, right male. I am not planning on hatching very many more eggs, but am facinated by this, and definitely would like to have an 80% accurate prediction next time! I did notice that some of our chickens lay consistently more rounded eggs, I also read some hens yield more female chicks. Any backyard scientists want to contribute? ThanksView attachment 3976291View attachment 3976286View attachment 3976287


Here is the article, it's very technical: https://pmc.ncbi.nlm.nih.gov/articles/PMC9832119/

A lady in my town did a hatch with 100 eggs IIRC and accurately sexed 98 of them with the pointy/rounded method. I'm sure this success would vary by breed, but in the ones she tested it was effective

 

[Creekchics]

It's as accurate as flipping a coin before each hatch. I had several hens that laid torpedo shaped eggs amd had both male and female chicks

I know what you mean about torpedoes, maybe the difference is more subtle in those? Believe me I now stare at those particular eggs and wonder

 

[Creekchics]

A lady in my town did a hatch with 100 eggs IIRC and accurately sexed 98 of them with the pointy/rounded method. I'm sure this success would vary by breed, but in the ones she tested it was effective

That's great to know, I definitely think some eggs are harder to differentiate, probably based on breed, I wish there would be a bigger study done and pay attention to breeds

 

[Creekchics]

In chickens the female determines the sex, so every egg yolk is predetermined as male or female before it’s even laid. There’s absolutely no way the shape of the shell, which comes much later, can determine sex.

I don't know, since the whole egg is so important not just the yolk it seems reasonable that it would be involved

 

[Susan Skylark]

47 eggs for this data set? While this is a fascinating idea, there is such a thing as statistical significance (which happily this paper does not even try to establish). I love the idea and they repeatedly state it will prevent the culling of billions of chicks annually, but that is a huge projection from 47 eggs! And from my extensive experience (15 quail is obviously statistically significant (joke)), each individual bird lays eggs that tend to be of a generally consistent shape (like my potato egg bird) but none of them lay 80 percent of one sex. I just don’t see this as a viable alternative (those magnets are much easier and maybe just as accurate (joke)). I would love it to work but if it did I would also think big poultry would be vastly eager to investigate, just like all those homeopathic cures for cancer that big pharma isn’t investigating (if there is a chance for profit, someone is bound to look into it). As for usefulness to backyard quail enthusiasts, first you’d have to hatch enough eggs to establish a baseline and then measure all your potential hatching eggs. But with quail you can’t physically sex them until 4 weeks of age (or later) and they can be harvested at 6 weeks so it isn’t as vital as those little roosters they throw in the wood chipper at 3 days old. Interesting but not exactly practical anytime soon, just hatch your eggs and eat your Roos! But if you’d like to establish a baseline, I’d love to see the data (if you don’t mind hatching a couple thousand eggs!). There is such a thing as sexed semen on cattle, they determine the sex of each sperm cell and weed out eighty percent of the unwanted sex, but that is on the cellular level not a whole egg and it is still only eighty percent accurate. Maybe I could publish my data on fridge eggs (n of 31) (joke)? Interesting but not statistically significant.

 

[NatJ]

And from my extensive experience (15 quail is obviously statistically significant (joke)), each individual bird lays eggs that tend to be of a generally consistent shape (like my potato egg bird) but none of them lay 80 percent of one sex.

Speaking of small sample sets...

I once hatched 11 chicks from one hen, and they grew up to be 9 males and 2 females. No, I don't have a count of how many other eggs failed to hatch, so I can't say whether she was actually laying eggs that were mostly one sex, or whether something made one sex hatch at a different rate than the others. But 9 of 11 is a little higher than 80% one sex (for a sample size that is too small to be statistically significant, of course.)