I disagree that this would have been better with heads rather than tails. I like the fact that I get to steal a private moment with the foal up front...mom doesn't even know we're here. :) Agree that cropping the sky out would do no harm, and might help, though I'm not sure how. 7 before and 7 now.
Too bad none of the horses are looking your way. You mostly have their backsides. Maybe waiting for them to rearrange would have improved this shot. I know that's not always possible.
compositionally I'd say this would've been more successful with more "heads" than "tails" Good exposure and nice colors. I'd have cut out any sky on this one since it isn't a very appealing color, not being blue at all.
Even tho it may not be tilted, it looks like it is. Should rotate to the left 1 or 2 degrees. But a great shot of the horses, I love the level tone it has.