temp and sex

[jasondgarza]

Does temp effect the sex of the hatching chicks. It seems like most of the eggs I hatch are all roosters. I like the hatching experience but should I change the temp to get more girls or is it like humans where it is predetermined by sex cells?

 

[ChickenCanoe]

Short answer is NO.
There is some evidence that temperature affects outcome in reptiles but not birds.

Similar to humans/mammals but just the opposite. The hen determines the sex of the offspring unlike humans where it is determined by the father.

 

[Mrs. K]

I have recently read on this forum, a reader put forward the rounder the egg, more likely a hen. So you would have to sort your eggs by bird, and pick the rounder ones? I might try it.

 

[azygous]

I'm hoping more people experiment with the shape of the hatching eggs, and let us know how it has improved the odds of getting pullets with the round shaped eggs. So far what I've read, people are reporting better than 50/50 in favor of pullets.

I'm planning on trying this myself this summer.

 

[AuntNomi]

I am also going to be trying the rounder eggs as well and see what happens. I am hoping it is correct for more hens. But I won't mind the cockerels either I guess. I am just ready to hatch some Ameraucana eggs already!

 

[aart]

I wanted to hatch eggs from a certain bird...she lays torpedo eggs, very long and pointy.
Broody hatched all 7 set, 1 died other 6 were 50/50 gender-wise.
But it would take boucoup hatching and recording of data to establish any finite conclusion....way more than 99% BYC'iers could/would accomplish.

I don't buy the shape thing, fertilization happens way before shell shape is established.
Maybe if it could be established that a certain hen continuously produces more females than males and she has a certain shaped shell,
then the shell shape theory might hold, even tho it would really be the hens proclivity to produce one gender or the other more than shape of shell.
But I guess it's fun to speculate as the gender of chicks hatched is always on our minds...will we get eggs.... or meat?

 

[jasondgarza]

Thank you all for the advice. I figured it was more like humans than reptiles. I'm just overwhelmed with roo chicks. I guess I'll have to learn how to butcher I just didn't want to do it unless I really had too. So far I have been able to rehire them fairly well so hope it doesn't come to it.

 

[dheltzel]

Reptiles don't have sex chromosomes, that is why some are temperature determined genders, also why there are no sex-linked traits in reptiles. The sex in mammals and birds is determined by sex chromosomes, so they sex is determined at conception, and also there are documented sex linked traits in many species.

The best you could hope for in manipulating the incubation temps is the preferential killing of a certain gender that might be less tolerant of temp extremes, not a useful outcome in my opinion.

Egg shape is also a lost cause. Consider this -- if there were anything to it, the commercial hatcheries would be all over this, the potential cost savings there are huge, imagine if they only needed to set half the number of eggs (or get twice as many pullets) in their expensive equipment. The layer industry would gladly fund any research that had a chance of finding a way to sort eggs by sex.

They did finally (at great cost for R&D) develop a process to sort the semen from bulls so that a far higher percentage of females are produced for the dairy industry. That "sexed semen" is much more expensive, but still used a lot by dairy farmers. Sorting eggs would be a similar challenge, with millions of dollars at stake for the lucky company the finds a way to do it.

So, I really doubt that old wives tales about egg shape.

 

[aart]

Thank you all for the advice. I figured it was more like humans than reptiles. I'm just overwhelmed with roo chicks. I guess I'll have to learn how to butcher I just didn't want to do it unless I really had too. So far I have been able to rehire them fairly well so hope it doesn't come to it.

You could look at it as another form of raising food, if you're gonna hatch you're gonna get males and they eat good on grill, then bones for stock, at about 15 weeks.
I found learning to butcher one of the more difficult yet satisfying parts of keeping keeping/raising. But I keep chickens for food and that's part of the responsibility of sustainable and 'real' food. If you're 'pet' chicken keeper, whole nother story.

 

[Mrs. K]

Several years ago, on the hatching and raising page, people put in for nearly a year, how many eggs they sat, and how many hatched. One added it to the totals above, and divided. At first as all statistics do, the percentages varied wildly, but over time, they began to average and there became much smaller swings.

It came very close to a 50% hatch rate. If you have been hatching eggs long, most of us have had a poor hatch or two, and sometimes a perfect 100% hatch. I have found that hatching smaller hatches actually gives me more chicks, but any hatch above 50% I consider a win. This was true under broody's or incubators.

All I am saying, while not perfect, one could easily set up a test to see if the shape was indicative as to the sex of the bird.

As a side note, even with the 50/50% that is should be, we have all known families were it did not follow the punnet square of probability. Ken had a cow that he liked very much, and she raised beautiful heifer calves, and he kept every one of them, as they too were good cows. She did not have a bull calf until her 10th calf.

It is a crazy hobby. If you are going to go dual purpose, eggs and meat, I do recommend upgrading to a higher quality rooster, getting a new one every two years. It does make quite a difference in the quality of meat. And getting a drill mounted plucker, it makes harvesting the birds so much easier!

Mrs K