Because after having his teeth floated, he's off his hay a bit, but still eating his grain.
I don't see any hay balls from quidding, so it just seems that he's eating, just not as much as I would like. I gave him three flakes Tuesday night, and Wednesday morning he had only eaten about half of it. I left that there and then I threw him another flake for the night later and gave him his grain, (have been placing his grain in his bucket tucked inside an old tire to prevent him from flipping it) and this morning he had left the stuff in the net and eaten about half of the spare flake and almost all of his grain, but not quite all.
So I left that hay and gave him a smaller portion of grain. I'm assuming that his bite is a lot different now and possibly he is very sore from the floating. He does at least seem to be drinking his normal amount of water, thank goodness.
Edit: After going up for evening feed, I discovered that not only was his grain bucket empty, but so was his hay net, no hay on the ground, and only an inch of water in the bucket! So maybe he is not so sore now. Plenty of hay, normal grain ration, bucket full up, woohoo.