Re: Rice bran

[Susan Evans Garlinghouse <suendavid@worldnet.att.net>]

> > > Would you please tell me what is wrong with rice bran?  I feed
> > > NaturalGlo (ride bran) during the winter.  Should I not be doing this?
> > >
> > > Amber


Ok, then, here's why I'm not fond of rice bran.  It's okay, it does have
it's uses on occasion, but there ARE some drawbacks you should be aware
of.  One, and for me, this is the biggie, it is extremely high in
phosphorus.  If you do not balance the phosphorus and calcium (ie, are
feeding more p than ca), then calcium is leached from stores in the
bones.  If you are feeding primarily grass and/or cereal hays, then in
all likelihood, your calcium phosphorus ratio is inverted, meaning
unbalanced, and the horse is getting insufficient calcium in the diet. 
OK, you say, so I'll feed more calcium.  Yes, you can do that, but most
people do so by feeding alfalfa.  Alfalfa is high in protein, which is
unfavorable for performance horse, and two, if you're in the Southwest,
contributes to enterolith formation.  The other way you can supply more
calcium is by providing ground limestone.  Fine.  Now you've avoided the
high protein and magnesium of alfalfa, but now not only are you feeding
excessive phosphorus from the rice bran, you're also feeding excessive
calcium to match all that phosphorus.  The problem with that is
predisposition to a syndrome called hypercalcitoninism.  This involves
homeostatic mechanisms in the endocrine (hormonal) system that regulate
calcium.  I've used the term in the past that "the hormones get lazy"
and got lectured by someone that 'hormones do not get lazy', so I'll try
to explain it another way.  What happens is that because there's so much
calcium all the time in the blood, the hormone proteins (parathyroid
hormones) that are responsible for mobilizing calcium OUT of the bone in
times of high demand are not normally needed, and so are not synthesized
except in very low numbers.  Then along comes a high-demand for lots of
calcium---such as during long, sustained exercise during a fifty-mile
ride.  All the calcium in the blood is used up and the horse needs
more.  But he can't mobilize it fast enough from the storage depots in
the bone because the proteins that do that are in very low numbers.  The
result is muscle fatigue and thumps.  Not good.

This is analogous to what's called "milk fever" in dairy cows.  If a
dairy cow is on high alfalfa while she's dry, her PTH hormones are in
low numbers because as far as HER system can tell, why bother mobilizing
calcium from the bones when there's always plenty of calcium around in
the blood?  Then the cow calves, she goes into high lactation, the PTH
can't mobilize calcium fast enough and the cow goes down.  Same
mechanism.

The third thing I don't like about rice bran is the price.  Most people
feed rice bran for the fat content, which is around 15-20%.  OK, that
means for a pound of rice bran for fifty-seven cents (at our local
prices), you've supplied around three ounces of fat, or about 1/3 of a
cup.  If all you're looking for is fat calories, IMO, you're better off
just feeding the 1/3 cup of oil (which is around 12 cents) and have the
calories but NOT have the excessive protein or the excessive phosphorus.

The only thing that rice bran has that you can't get
just-as-good-if-not-better elsewhere is gamma oryzanol, which acts
somewhat similar to anabolic steroids.  It does add more bloom and
tissue growth to a horse than you'll get from just fat, although DVMs
like Heidi say (and I believe her) that it also contributes to ulcers in
young horses under two.  You can get gamma oryzanol in a purified form,
so if you are feeding rice bran for the gamma oryzanol content, I'd say
buy it by the bottle and add that to the feed and STILL avoid the
excessive protein and phosphorus.

I'm not saying that rice bran is a terrible feed and that there's no
place for it in a feed program.  I just think you can get all the
benefits elsewhere without the drawbacks and that rice bran isn't worth
all the marketing hype and the price.

Susan Garlinghouse