Hi Ann,
Probiotics, probiotics, probiotics. Antibiotics, fever and stress will
all kill off the intestinal microflora and suppress feed digestion,
alot. Go get a good probiotics supplement and start giving it to him on
a daily basis, but first start out with a tube of Equine Bene-Bac and
squirt it down his throat. A third of the tube today, another third in
a few days and the final third a few days after that.
Without crunching the numbers, your diet looks okay. Give him about
1.5% of his body weight per day in forage (about 12-13 pounds)---the 60%
grass hay and the rest in alfalfa. Preferably in baled hay form,
because you want it for the bulk. Add 5-6 pounds per day of the grain
mix, split up into two feedings. Add a handful of WHEAT bran, and I
mean A HANDFUL, not a pound or a scoop or a bucket, to the grain and a
little corn oil, whatever you can get him to eat. Sometimes they take
awhile to decide if they like it or not. The more you can get him to
eat the better. The bran will also give you a base to add in your vets
mineral mix. Forget the rice bran, the other grains are higher in
energy and that's what he needs.
Take some time to switch him onto this much grain if he's not used to
it. If after a few weeks he's cleaning up everything and looking for
more, increase the grain by another pound or two. Try to up the corn
oil as much as you can. Don't increase the hay until he's first
cleaning up a good 7-8 pounds of grain a day. Twelve to fourteen pounds
is plenty to maintain gut integrity without filling him up so that he's
not interested in his grain (I have a very hard keeping TB broodmare
that will ignore grain to go clean up every last little bit of hay,
straw, wood shavings, cardboard boxes, etc before eating her grain with
a "poor me" expression on her face).
I've used this general formula numerous times and have always been able
to put and keep weight onto the hardest keepers within a few months.
Good luck,
Susan