No, not that question.
Okay, so here’s what I think I know about chickens and eggs. Chickens lay eggs. If the egg has been fertilized, a baby chick happens. If there’s no fertilization, the chicken can still lay an egg.
Is that right?
What about other birds? Do they lay eggs that don’t hatch into babies?
Sure. But not as productively as chickens.
It can happen to parrots/cockatiels kept as pets. I know someone who just found out her pet bird is actually a female when she laid a couple eggs after 20 years of thinking it a male bird. And I have a friend whose turtle lays plenty of unfertilized eggs most years.
We had a lovebird that was an egg-laying machine. She had no mate, so of course the eggs never hatched. She got egg-bound twice (where the egg gets stuck in the cloaca); the first time we took her to an avian vet to have it removed, and the second time, we found her too late. 
Funny, the first time she laid an egg, Mr. S thought it was a fake one that I had put in her cage as a joke. Now where the hell would I get a fake one-inch egg, especially with little flecks of blood on it??
How did rural folks know which hen’s eggs were fertilized & which were not? If you want to eat or sell eggs and raise chicks, what do you do?
Thanks.
Segregating the hens/roosters also works. Just keep the rooster out of the coop that lays food eggs, and in the coop that lays chick eggs.
My grandmother had one coop, a rooster, & a bunch of hens. She would sell or trade butter & eggs and also raise chicks. Of course, there would also be a chicken for frying on Sunday. I never thought to ask her how she kept everything straight.
A guy on my ball team runs a small hobby farm. The rooster is kept next to the hens, but in a separate pen with mesh keeping them apart. There’s no chance for avian hanky panky, but they can flirt. So there’s no need for candling even.
None of the eggs are fertilized unless he wants to breed chicks at which point the rooster gets to share a pen with the girls. The hens lay regularly, so not all of the eggs are fertilized during breeding time, so that’s when he has to candle, and the fertilized eggs are put in the incubator. He had cute wee chicks last time I was up there for a barn party.
Well, if you collect eggs every day, you can certainly eat the fertilized ones. Refrigerating will stop the fetal development. Many people keep the roosters right in with the laying flock and only raise chicks if a hen goes broody. This is my plan.
We have 4 hens and one rooster. He is just for fun (ours and the hens). We eat all the eggs, and every few years we buy a coupla chicks to replace aged hens as well as those who get eaten by fox/raccoons/etc.
It’s also worth mentioning (I hope) that chickens are the product of thousands of years of artificial selection, as humans have bred for egg production. Their wild ancestors wouldn’t have laid at the same rate.
Yeah, nofloyd’s link mentioned breeding. I read a lot of historical fiction, and it seems that eggs were near precious up until the last hundred years or so. In westerns set in the late 1800’s, I’ve read about women sharing eggs to bake cakes for special occasions. They weren’t cheap or common. (The eggs, not the women.)
Nothing at all really.
Eggs don’'t just spontaneously hatch. They need to be incubated for weeks. No incubation, no hatching. I keep my rooster with my hens permanently. I collect the eggs every day. Since eggs don’t hatch overnight there is no problem. You can’t tell a day old fertilised egg from a day old unfertilised egg. You also don’t need to refrigerate the eggs to stop development. Eggs need a very high temperature (40oC IIRC) to develop. Unless you live in Death Valley your eggs won’t develop at room temperature.
Occasionally a hen will go clucky and try to incubate her eggs. If I don’t want chicks then I will toss her out the door every morning, and after a few days she will stop. If I want chicks then I will collect eggs and let her sit on them. It’s that simple.
I’m not sure why these people are saying they keep the rooster separate from the hens. It seems unnecessarily stressful to the animals and achives nothing that I can see.
That has nothing to do with breeding, it’s all down to diet. Hens will only lay if they have an excess of protein and calories in their diet. In frontier regions protein was scarce, so most hens would only lay every second or third day, and they would often go off the lay altogether for weeks. The cleverer people would obtain vermin such as groundhogs and squirrells and boil them into meatmeal for their hens, thus turning low value protein into high value protein.
Even the really ancient bantam breeds will happily produce an egg every day if you feed them right. Modern breeds may produce larger eggs, but they don’t produce many more eggs.
Smart, but that had to stink up a kitchen.
No, it wasn’t usually done in a kitchen inside the house, but an outside kitchen (aka ‘summer kitchen’). But even if it was done inside, why would cooking squirrel meat smell much different from any other meat?
It’s not the smell of boiling meat that would be nasty, but the boiling hair, blood, fecal matter, etc. That’s assuming the entire animal was just thrown into the pot.
Thank you. This answer jibes with my recollections of my grandmother’s methods (or lack of) in matters of the hen-house. I suppose my stumbling block was not knowing how far along a fertilized egg would be by the time it was laid. I had visions of cracking a morning egg & finding an embryo or something. But, you seem to indicate that this is unlikely if the eggs are gathered every day.
Thanks again.
Just thought of another question…
How many eggs are in the pipeline at any one time on a typical hen?