It really depends on your opponents - I tend to lead for half pot in these situations - It will help give you an idea of where you're opponent is at in the hand.
^probably the best play
To be fair, you might've gotten yourself into trouble by calling something like that from the small blind. Your range on sb should be a lot tighter than your big. You may have hit the trips but now you're at a risk of being trapped. But as others have said it really depends on the players at the table and how wide you've noticed their ranges to be.
With that said - This is a position where you could actually have an advantage. You're early, out of position and most would think it's unlikely that you'd call with mid-range connectors and, they're likely to be holding a face card with rags due to their position and just raising/calling the minimum. But you do have to be scared of a slow-played monster or a pocket 4 that hit on the board, once again, pretty unlikely.
Donk betting here would be a decent play because:
1 - You gain information on those left in the pot when they call/raise,
2 - You can minimize the players in the pot thus possibly increasing your
equity and,
3 - You could take it down right there and then.
An aggressive play is probably wise - plus you're probably ahead by a decent amount of the time given the board.
Put a decent bet out there and see if anybody calls. They've probably got a/k, a/q, a high pair or a face card with the 4, all of which you have dominated. If a face card comes on the turn/river, you may be beat so you can either three barrel it and hope you hand holds up, or you can slow down and just call it out if you still feel strong.
But as most have said, it depends on the players, if they're bluffers you might want to call a bet or fire into them to scare them off. If they call again, they've probably got something big, but still, unlikely to be the boat. Judgement call there.
You're definitely likely to be ahead most of the time, less likely up against a boat, and even less likely a kicker race.
My two cents.
