Cows don't conveniently turn themselves into hamburger when they die; that isn't true today and it certainly wasn't the case back in Medieval times. You needed a butcher to handle those sorts of gory details, and - unless your budding city is inhabited only by vegetarians - you will probably need a butcher's yard. So here you go; a butcher's yard.
https://www.planetminecraft.com/project/butchers-yard/