I've been off doing other stuff for the past ten days and logged on this
morning to 600 messages (eek) so sorry if I'm a little behind the power
curve and someone else has already answered this.
The analysis as above is almost a 1:23 calcium phosphorus ratio. This
means for every 1 gram of calcium provided, 23 grams of phosphorus is
also provided. This is extremely inverted and one of the main reasons I
don't care for rice bran (don't everyone start posting about what a nice
shine it puts on horses, I know, but my horses are shiny too for alot
less money AND with a balanced mineral ratio). Because the above
numbers are in "per cent", it applies to 1 lb, 2 lb or the whole bag.
To calculate the exact amount of (for example) phosphorus you are
feeding:
1. Take the number of pounds of rice bran you're feeding (say as an
example 2 pounds), multiply by 1000 and divide by 2.2 to convert the
pounds to grams. 2 pounds x 1000)/ 2.2 = 909 grams of rice bran.
2. Multiply the number of grams by the per cent of the nutrient you're
interested in. Notice that for 1.6%, you don't multiply by "1.6", you
multiply by either 1.6 PERCENT (if you have that key on your
calculator), or by .016 (just take the percent number and move the
decimal point to the left two places). Example: 909 grams of rice bran
x .016 = 14.54 grams of phosphorus supplied in 2 pounds of rice bran.
Since a mature 880 pound horse at moderate work has a requirement of 25
grams of calcium and 17 grams of phosphorus, just 2 pounds of rice bran
is already more than enough phosphorus and not even close to enough
calcium (.636 grams of calcium). If you're feeding the horse 2 lbs
of rice bran, plus let's say 16 pounds of bermuda hay and 2 pounds of
corn, the total calcium being supplied in the total ration is 22.64
(deficient) and 31.16 grams of phosphorus (sufficient), with a
calcium-phosphorus ratio of .73 to 1 (inverted, not good).
This isn't the end of the world, just an indication that if you're
feeding high phosphorus feeds like rice bran, you should try to keep the
calcium-phosphorus ratio balanced ideally around 1.7-2 to 1. Usually
easy to do by adding a pound of two of alfalfa without having to worry
about too much protein, etc.
Hope this helps.
Susan Evans