Interesting observation about chick genders

[RiverOtter]

Interesting reads on the topic:

https://www.independent.co.uk/news/drop-temperature-can-change-sex-chickens-1238516.html

https://www.mypetchicken.com/backya...incubate-eggs-that-will-hatch-female-H99.aspx

Sadly guys, the first article was posted in 2011. Professor Ferguson has had a decade to prove that, and hasn't.

And from the 2nd article;
A much more recent study published in 2013 (Poultry Science, Volume 92, Issue 12, 1 December 2013, Pages 3096–3102, https://doi.org/10.3382/ps.2013-03378) found no evidence of temperature-dependent sex determination or sex-biased embryo mortality in the chicken
and
At this time, unfortunately, there is no replicated empirical evidence of temperature-dependent sex determination (TSD) or sex reversal in chicken embryos.

It is easy to prove in the species of reptiles that it works in. You can see proof in a single clutch, and recreate the results over and over. But it isn't true for every species of reptile, and sadly, it is not true for chickens.
There is some evidence that points to younger roosters fathering more males and older ones more females, but sadly, I don't have time to pull up the studies right now and the difference wasn't really enough to get wildly excited over.
But please guys, look it up!

 

[Yardmom]

The hens determine the sex of the egg. IF the temperature affects anything it would be a better survival rate of one gender. The only influence the roo has is how "happy" the hen is.

 

[RiverOtter]

The hens determine the sex of the egg. IF the temperature affects anything it would be a better survival rate of one gender. The only influence the roo has is how "happy" the hen is.

You are right on both counts!!
I had a minute to find the study and it is hens, earlier hatches are more males.
https://pubmed.ncbi.nlm.nih.gov/18030680/

And right below that search result in google! very cool.
https://poultryperformanceplus.com/...ation/302-male-female-ratio-in-day-old-chicks

Certain sexes will have more fatality based on type and temp. Ironically, the ones that die are always the ones we want.

 

[kyeschicks]

Interesting

 

[Feath3rDust3r]

It's very interesting. I'm pretty sure that it's just a bit lucky because if it was concrete the big hatcheries would have it made by now!

 

[ChickenWhisperer101]

In April/May I had about 90% hatch rate...and then in July//Aug it was about 70%.

I actually thought the drop in success was due to my incubator so I bought a new one... but through the winter the hatch rates are only about 50%. The eggs do start to develop but they don't get much past 8 days. It will be interesting to see if the rates get better again in the spring

This is odd, yet cool

 

[RiverOtter]

It's very interesting. I'm pretty sure that it's just a bit lucky because if it was concrete the big hatcheries would have it made by now!

The differences are minor enough to really make no difference, when you are hatching thousands of chicks year-round.

If you're interested in some homework, the hatcheries were doing research based off this study, to try to skew the sexes, but still with limited results
https://academic.oup.com/icb/article/53/6/902/728865

But it seems the real breakthrough is in-ovo sexing; being able to check eggs for certain chemical markers so that male eggs can be used for eating and female eggs hatched. It's in trials in Europe and Japan.
https://inovo.nl/solutions/in-ovo-egg-sexing/

 

[Wangxian520]

The problem is that birds are not reptiles, so you can't just expect them to follow that logic 100% of the time

But, the ancestors of chickens and all modern birds were dinosaurs the theropods in particular and the theropods of the Triassic, Jurassic and early Cretaceous were cold blooded and it wasn't until very later in the Cretaceous did warm blooded theropods like T.rex and raptors evolved from those cold-blooded types; thus considering the dino ancestry of birds, temperature still might affect the gender ratios somehow.

 

[Mellowmalt]

that article is very interesting, it shows incubating is possible at 36.7 degrees C with only a 2% drop in hatching which is negligible. Very good.
It also shows that incubating at 38.3 is doable and should only cause a 10% additional loss in chicks.
Thats good info, also about the male ratio being unaffected.

 

[chickengr]

what I have noticed is that my dogs and cats in hot years had more male babies. the winter hatched chicks mostly are females, the eggs that do not hatch at winter probably would hatch males. I do not think that embryo can change sex.