I just have to do a bit of a correction here!!! As a chook farmer. Firstly I’m in Australia and can only really speak for Australia.
Ok so here we go: broiler (meat) farms break my heart and so do most egg farms. If you want to buy eggs where the birds are treated well you want to buy from a pastured free range farm.
On a free range pastured farm the hens are in paddocks with green grass (normal free range means the get open access to the sky. This means a dirt yard during the day and a shed at night). Only the breeder hens have access to a rooster so only eggs that are wanted are fertilised. Those chickens are bred in SMALL batches of under a thousand at a time. Breeding your own birds is costly.
Due to the costly nature of breeding and raising birds there is a WHOLE other industry for breeding and raising the birds to point of lay. The hatchery industry often sells unwanted pullets (girls) and cockerels (boys) to local markets, where they get raised up as farm pets or to be eaten at Chinese restaurants (a lot of people from other cultures prefer the taste of rooster to the hens we are used to). It is rare for chickens that could otherwise be sold to be disposed of. Due to animal welfare legislation, and also simply because it’s a waste of time and money.
So your eggs are safe from tormented chickens. And if you are worried about the happiness of the birds you consume, look at your local farmers market for the small pasture fed free range organic sellers. This is for both meat and eggs.