I am feeding U-Gard powder to my Perch/X mare to help calm the digestive system. I don't know that she has ulcers (and she has a very stress free life) but I feel as though she may occasionally be having gas pains, possibly from something she is finding in her pasture. Are there any negative effects from feeding this long term? I am feeding about 1 ounce a day with her oil and supplements. Also, is there anything natural (herbal) that you know of to calm the digestive system?

U-Gard� 2X Powder
Corta-Flx, Inc

Description:
A calcium feed supplement for foals, ponies and horses in training and competition.

Ingredients:
Calcium Carbonate, Kaolin, Diatomaceous Earth, dried Apple Pectin Pulp, Magnesium Oxide, Zinc Oxide, Methylcellulose, Silicon Dioxide, Iron Oxide, Mineral Oil, natural and artificial flavors.

Guaranteed Analysis:
Calcium (min): 2.5%
Calcium (max): 3.5%

Thanks.