We had a similar experience at my house one time, except it was in a bowl and all we saw was blood in the yoke. It had not been quite as developed as the one in your egg.
Those are supposed to be pulled before they make it out of the packaging plant. They shine a light through the egg and detect if there is an embryo inside. The process is called "candling." Of course it is imperfect especially if the egg is very recently fertilized. I've gotten one or two with a red spot in the yolk over the years, but nothing close to a developed chick.
where do chickens come from? eggs! If one needs more chickens, one could let the eggs be fertilized and then incubate those eggs. all you need is a rooster in good health. Eggs that are incubated in this way won't be in the grocery store in cartons, because they will be chickens instead.
It's a very different supply chain. You don't just chuck a rooster in with your layers because then you have to inspect all your eggs.
New layers are bred away from the main flocks in relatively tiny volumes, under 1% of layers' eggs. Culls may drive a need for more layers to be raised, increasing that percentage but the cycle rate for these hens in intensive farms is pretty regular already (<18 months) so I doubt they'd invest in the additional hatchery facilities for a temporary population lull.
> increasing that percentage but the cycle rate for these hens in intensive farms is pretty regular already (<18 months) so I doubt they'd invest in the additional hatchery facilities for a temporary population lull.
this actually speaks to my point more than the other replies you (and other) gave. A temporary shed for layers to nest isn't insurmountable. Especially if you know that the end result is more money for you because of supply issues.
What i am not sure about, is why that didn't happen, since you say it did not. anyhow, it was just an idle thought. If i was selling eggs, and suddenly a quarter of my flock was wiped out - by a fox or something - i would probably immediately borrow a rooster and let the layers nest. I've done it before, so i'm not just "guessing." Contemplating protecting nesting chickens is the only thing that gives me pause, as i don't really like "outside dogs", but i have a herding dog.
Chicks are processed at enormous speed and volume. Males are killed and the females are boxed up and sent to farms. This is factory level work and involves expensive automation. The size of flocks makes doing this without automation unfeasibly slow.
So egg farmers who lose a flock just buy another. They might have to wait for their scheduled order to come in. They don't spend $20m on a temporary hatchery facility.
https://www.delish.com/food-news/a63842548/what-are-fertile-...
You will find a number of people who have claimed to have hatched a number of types of birds from store eggs, including chickens.