> Feeding 20 lb hay will give you 18 Mcal and you would need to feed 2.75 lb Natural Glo.
>  You would then be feeding 0.17 lb Ca and 0.10 lb P, or a Ca/P of 1.7 which is fine.
Well, in my opinion, maybe not all that fine, although I agree a 1.7 
Ca:P ratio is OK.  Feeding .17 lb of Ca and .10 lb of P is 1500% and 
1200% of the required amounts, respectively.  Excessive in both cases.  
It also provides approximately twice as much protein as is required, 
definitely a bad thing in endurance horses.
So I have a
> > question. We normally feed 50/50 alfalfa/oat when the horses are in
> > the barn (otherwise on irrigated pasture).  Do you see problems
> > supplementing with Natural Glo in this situation? (light-moderate
> > work)
I have an equine nutrition spreadsheet program that crunches all these  
numbers.  If you like, I can run it through and see what it says.  
Personally, I think there are better approaches than feeding rice bran, 
but that's just me.  If you can e-mail me the horse's weights, I'll 
crunch it this weekend and post the results.
Susan Evans