The real question is how far do you take selective breeding.
Do you want chickens that can't stand on their own legs? Olden days: no, currently: yes.
Do you want cows so fat that they can't naturally give birth to calves? Olden days: no, currently: yes.
How do you breed animals? Oldens days: put the male together with the female. Currenly, jerk of the male and inject the semen in the female.
It's all industrialized. And what selective breeding has to do with how animals are treated? Everything. Unless you claim chickens too fat for their legs, cows too fat to give birth, etc, has no impact on their well being.
