i’m not vegan, but the egg industry is probably one of the most atrocious concerning animal welfare iiuc. they do slaughter chicks in droves—just not for meat
Animal welfare should not focus on if an animal dies if the alternative is for it to never live at all. Any amount of time, even a day after hatching, is greater than zero.
Instead we should focus on quality of life and how humane the death is.
“They aren't chickens which wouldn't survive in a non domesticated environment.”
You would be very surprised how quickly animals can adapt to a new environment. There are plenty of examples of domesticated animals being released into the wild and doing just fine.
I'd think dogs are mostly able to because they're still around humans and can scavenge off our garbage. Any breed that's not damn close to a wolf, I'd expect not to be able to find/catch enough food to survive long if dropped in actual wilderness.
Chickens would become food for other animals in days, at most. It's hard enough to keep that from happening when they're kept, let alone in the wild.
Cows are like giant, extremely stupid deer, so I doubt we'd tolerate them in the wild anywhere even slightly near civilization, putting aside their ability to survive on their own (which I also doubt—first bad Winter would take care of them, I reckon).
Not that we we will be able to test it, but I would bet against your promise. I don’t see a reason why cows or chickens couldn’t survive in the wild. Not in all areas obviously but I am sure there are areas where climate, vegetation and predators allow them to thrive. We have wild turkeys, we have quail, so why not chickens? And if horses can survive, then cows can too. Horses are way more fragile than cows.
Instead we should focus on quality of life and how humane the death is.