Quick note: caciocavello is not horse milk cheese. It's a pasta filata cheese (stretched curd cheese) that is aged. It's formed into jug shaped cheeses with a string tied to the top to age it. Normally there are 2 cheeses tied to either end of the string and you hang them. It's called "cavello" (horse) because you could put it on horse back with one cheese on either side of the horse.

It's essentially a drier version of mozzarella, though (very similar to Italian provalone).

Edit: non-sensical sentence