Kohnke’s Own Cal-XtraConcentrated calcium supplement for horses grazing on oxalate pastures, as well as horses in training and growing horses. CAL Xtra is especially formulated for horses consuming tropical pastures or hays where calcium uptake is reduced by oxalate compounds in the pasture and hay. Oxalate compounds bind calcium, reducing its availability, which can lead to an artificially induced calcium deficiency. Contains a concentrated source of bone minerals