And speaking of acreage, grass and manure......
I've got a big QH and a TB/QH mix.
Between them both, they put out about 15 gallons of manure a day which means that I'm dealing with close to 450 gallons a month.
That's a lot of crap to shovel-up and dispose of.
I've found it much easier to deal with if I divide my pasture in half and rotate the horses from one side to the other each time they're wormed. Doing that also helps with controlling parasites. And it gives whichever grass they aint on at the time a chance to keep growing during the spring/summer.....'cause if I don't get them horses out of there occassionaly, they'll eat it clean-down to the dirt.
It is beneficial to whatever pasture you can spare, to let some of it go to seed sometime between the end of summer and the first fall frost. That not only ensures that it re-seeds itself, it later creates a layer of dead grass for protection during realy cold weather, hail storms or hard rains. And if you add some of that dried manure you've been collecting, it sort-of self-mulches and fertilizes itself when you run over it with a mower a couple of times later on, just before spring.
No way could a person manage all that with less than 1 AC-per horse to work with. Or at least, I know that I couldn't.
My two are on 2 AC's, plus there's a fenced-off, quarter-acre excersize yard which surrounds the barn. But even with that amount of ground to work with, there is some years that things still don't work out just right.
Your results may vary somewhat, depending on your own methods of up-keep. But if you move that horse onto a half-acre...and if you still have grass on it a year later..please let me know how you managed it.
DGW.... who still aint too old to learn.