[jterrys]

A lot of it, imo, is cultural more than mass production. Chickens are kind of a prime example of that. Factory raise them for the breasts and maybe thighs and essentially discard the rest from a consumer standpoint. I'd wager the ratio of chicken raised primarily for chicken breasts far outweigh the added consumption of thighs and wings. Wings in particular are so funny to me... most places sell "boneless wings" alongside actual wings that are just cubed chicken breasts.

If culturally, there was more emphasis on using other parts of animals in our (presumably American diet) we'd definitely get more mileage out of every raised cow, chicken, and pig.

...but this actually brings it into a more 'chicken or egg' (pun intended) contradiction. Because farm raised animals typically don't make the base for good stock since they don't consume good food. They don't consume good food because they're mass produced on a budget. They're mass produced on a budget because consumers typically pick only a few cuts of an animal and discard the rest.