Considering how many of them say this, it's statistically implausible due to how rare these kinds of farms actually are.
Big-ass, industrialized factory farms need to exist in order to accommodate the demand that there is for so many people to consume flesh and secretions.
Ultimately, in addition, even if it were true, engaging in "humane animal slavery" still does not justify it.
Pre-vegetarian, this was the first thing I tried. After a few months it became obvious that it was extremely impractical and not in any way scalable, and the only solution was to cut out meat entirely (veganism was another year or two down the line after that).