Beet pulp is right on the edge between being a forage (fiber content
greater than 18%) and an energy feed (fiber less than 18% and protein
less than 20%). Beet pulp has a fiber content of 18.2%, a protein
content of 8.9% and an energy content of 2.33 Mcal/kg, which is lower
than oats, bran (or any other grain) and only slightly higher than early
bloom alfalfa. So it does have some very nice uses in horse rations,
specifically in horses which don't need a ton of grain, but maybe could
use something to occupy themselves with during the day (here in So Cal,
stalled/bored horses are common, so this is a factor). The Ca:P ratio
is also good---one of the problems with many grains is that provide alot
of phosphorus, sometimes a problem if not balanced with the calcium.
Beet pulp already has a Ca:P ratio of 7:1, so if you're feeding it, you
don't have to worry about the ratio. The other nice thing is that it
provides more energy per kg than does alfalfa (and a significant amount
more than the other hays) without providing alot of protein (that's
good). It also provides a nice balance of .54% lysine (the amino acid
you're most likely to be deficient in--not as much lysine as alfalfa,
but quite a bit more than the other forages, and almost the same as
wheat bran without the excess protein or phosphorus).
In short, beet pulp has ALOT of advantages without alot of the
disadvantages of some other the other feeds. The one big drawback, and
you CANNOT ignore this, is that you must soak it before feeding. Patty
Chase has already posted the problem with impaction and blockages, and
described how to soak it. If you're willing to put up with the minor
inconvenience, then it's a very good feed.
Hope this helps.