Less food, more caecotrophs!

I dont get it.

I have been taking turns in cutting back pellets and veg from sammys meals so I can find out which one is causing him to make extra caecotrophs but it aint working.
I've only been doing this for a few days but the problem isnt getting better, I cant bring myself to only give him hay.
He gets two meals a day. Its always in the afternoon time that he produces extra caecotrophs

Any suggestions?

deleted

Can he have daytime access to grass? If so put him on a hay and grass regime for a wekk and see if that has any effect.