Bit,

I have the original paper as a pdf file but havn't read it in detail yet. It seems they've isolated some genes on the mitochondrial DNA which are linked to increased ATP and energy production. The fact that the offspring get all their mitochondria from the dam is the main issue for handicappers in considering the relative role of the dam vs. the sire. Locating the genes and mDNA testing would be of great value for those about to spend big bucks on a yearling or 2YO.
As I said, I think it's too long to post but will glady send it to anyone interested. If anyone knows how I can send a long pdf file directly here, I can do that too. I'll read it in more detail and see if I can answer your questions.

Bob