I'm voting 1 1/2 on this one. I know the 2 1/2 year olds on this farm are almost always in the 100-110 inch range, which this guy is not. And even though you can't see the profile, he looks narrow.

Furthermore, here is another photo of the 1 1/2 year old I mistakenly took for a 2 1/2 last fall and put an arrow through is boiler room. At first glance coming through the woods you think 2 year old, when he's on the ground there's no mistake he was just a great 1 1/2. Same farm.