It wasn't so much the feed aspect that fascinated me Dan.
Rather it was the underlying suggestion that, whilst apparently still allowing the horses to perform quite credibly, the level of respiratory disease they had was such that it retarded the gaseous exchange in their lungs, thus causing their TCO2 levels to rise above the prescribed threshold. It seems someone has really given a lot of thought to this. I don't think it's at all probable let alone possible however, as I said, you've really got to hand it to them.
We've certainly come a long way from 'the rampant Cocaine abusing & habitually stall peeing groom' defence that was rolled out by a trainer in the US many years ago.