Question: So here are my questions: Do you think my horse's lunch ( the beets,etc) is too much for one feeding? Is a half pound of bran enough to balance the calcium in his rations?  The bran is 14% protein, but is that protein available to the horse?

I am feeding my horse one pound of no sugar added beet pulp (dry weight, but I soak it in five quarts of water before I feed). To offset the high calcium in the beets I add a half pound of wheat bran. Ten years ago this horse (a 15y.o. Welsh Cob X QH gelding) had surgery to remove a large bladder stone composed of 100% calcium carbonate and I was advised to restrict his calcium intake. He also gets one pound each of SafeChoice, fortified alfalfa/Bermuda pellets, Timothy pellets, three carrots and supplements (1.5 g. of C, 1600 IU of E, 4,800 mg of fish oil, 1TB sodium chloride, 1TB potassium chloride, 1 scoop Remission, 1.5 scoops Source, 8 mg. glucosamine, 10 mg. MSM, 1/4 cup of canola oil, and 12 pounds of grass hay. He gets 3 pounds of hay at 7AM, the beet pulp mixture at 11:30AM, then goes into a thin pasture. He is put back in his dry lot at 4:30PM where he gets 2pounds of hay. At 10:00PM he gets 7 pounds of hay in a slow feeder hay net.

He lives with a Haflinger pony (13.3hh and 900 lbs). The pony could lose some weight, but the horse is a “5” at 1,050 lbs.

Dr. Kellon: When you feed more calcium than the horse needs, whether you balance with phosphorus or not,  it has to be excreted in the urine and  increases the risk of calcium stones. Bran can help block the absorption of the calcium but it's much easier on the horse and more reliable to not feed extra calcium. Most grass hays provide all the calcium the horse needs. The SafeChoice and alfalfa/Bermuda pellets are also adding excessive amounts of calcium. Could you simplify his diet?