Here's my .02 on pellets at rides and on alfalfa. Re pellets,
nutritionally, they contain the same amount of protein, energy, etc etc
as does flake hay. HOWEVER, due to the processing involved in turning
the hay into pellets, the particle size is smaller when it goes through
the digestive tract. One of the things you want during/before a ride is
bulk in the gut to help keep the gut moving during the stress of the
ride. Flake hay will provide more bulkiness than do the pellets, so it
is a good thing to provide some flake hay before/during a ride. The
other nice thing is that a horse's water consumption will increase at
least in part due to fiber ingestion, so making sure the horse has some
bulk in his belly is also a nice way to encourage the horse to drink
during the ride (I know, there are other ways as well, this is just one
more). A nice load of fiber also acts as a reservoir for water and
electrolytes, another good reason. Anyway, my suggestion would be to
provide some flake hay a day or so before the ride and during the ride
AS LONG AS the type and quality of the hay is roughly equivalent to the
hay making up the pellet. That is, if you feed alfalfa/bermuda blend
pellets (which I do, too, by the way), you could provide him with some
decent quality bermuda flake hay, but NOT dairy quality super-rich
alfalfa. Remember that for these purposes, you're trying to provide
added bulk, not power-packing in extra nutrients that he's not used to.
Especially for endurance horses, I agree that really rich alfalfa (dairy
grade) is not the best choice. Too rich, too high in protein, etc etc.
Everyone's heard me yammering on this one before ad infinitum. Good
alfalfa (fine-stemmed, leafy, early to mid bloom) is fine, but I'd
suggest less than 50% of the hay ration be made up of alfalfa and
personally I prefer about 25% alfalfa/75% bermuda if at all possible,
although you have to check and make sure the calcium/phosphorus ratio is
OK, especially if you're feeding grain as well.
Hope this helps.