I'd say extend the roof all the way so that our lovely animals don't get wet when there's inclement weather. Also, for the chest into which all the drops go. I'd say see about trying to make it on the first floor. I can see it getting perhaps a little tiring having to climb the ladder every time in order to get to the barn loots.
I'm also hesitant when I see cobwebs and redstone torches, simply because on many texture packs (including default), they make the barn look dark, and a little gloomy. Though I can perhaps appreciate the homage to Charlotte's Web, perhaps just one spider web instead of more.
That's all of my critiques; otherwise, looks great!
Also, your animals look pissed.