I was doing some literature searches and came across a paper that is almost exactly the information that was presented during the nutrition seminar. I can't remember whether the guy who wrote the paper (Duran) is the same person who presented at the seminar, but the company is the same - Kentucky Equine Research. Unfortunately, there is no year on the paper so I'm not sure how much older the information in the paper is than what I heard at the seminar. And, while it has references, I think the in-text citations are inadequate - BUT I think it's nice to see the information written down so it can be evaluated, rather than what I remembered being presented.
If you are interested, the paper has been added to the Mendeley group (you can access it from the side bar) and is called "Feeding the endurance horse".
Update: After reviewing KER's "published research" page, I think the paper I posted was probably this one: Duren S, KM Crandell. 1998. Feeding the endurance horse. World Equine Veterinary Review. Vol 3/2:28-35.
Other citations that might be of interest to you (but I don't have the time to look up and post the actual documents) are:
Crandell, K.G., J.D. Pagan, P.A. Harris and S.E. Duren. 1999. A
comparison of grain, oil and beet pulp as energy sources for the
exercised horse. In: Equine Exercise Physiology V, pp. 485-489.
Harris, P.A., J.D. Pagan, K.G. Crandell and S.E. Duren. 1999. Effect of
feeding Thoroughbred horses a high unsaturated or saturated vegetable
oil supplemented diet for 6 months following a 10-month fat acclimation.
In: Equine Exercise Physiology V, pp. 468-474.
Bullimore, S.R., J.D. Pagan, P.A. Harris, K.E. Hoekstra, K.A. Roose,
S.C. Gardner and R.J.Geor. 2000. Carbohydrate supplementation of horses
during endurance exercise: Comparison of fructose and glucose. Journal
of Nutrition 130:1760-1765.
Duren, S.E., J.D. Pagan, P.A. Harris and K.G. Crandell. 1999. Time of
feeding and fat supplementation affect plasma concentration of insulin
and metabolites during exercise. In: Equine Exercise Physiology V, pp.
Pagan, J.D., I. Burger and S.E. Jackson. 1995. Long-term effect of
feeding fat to 2-yearold Thoroughbreds in training. In: Equine Exercise
Physiology IV, pp. 343- 348.
FYI - All these papers hare some how associated with KER's research program