The whole idea about him apple bobbing is for him to take in lots of water while he's fumbling around in the trough - to make sure he stays nicely hydrated. I think he's getting a bit too good at it though!
Hes very good at it, and amuses me greatly with how far h'es prepared to put his head underwater to catch an apple! None of the others can apple bob - they're all useless!
That's interesting. When I was a child the riding school horses were all kept in an open sided shed between lessons. They had hay, but no water so at the end of each lesson the riders would take them to the trough to drink (I know, wouldn't be acceptable nowadays!) The horses used to put their heads into the water up to their cheekbones, presumably because they were so thirsty. It was quite a revelation when I took up riding again as an adult and saw how horses drank when not deprived of water.