The health and structural soundness of the equine hoof is dependent on a strong, relatively thick sole. A thin sole provides insufficient protection to the foot and predisposes a horse to bruising and lameness.
In the current study, a trend for greater accumulation of sole tissue was observed at various times and at multiple locations within the hoof in lactating mares supplemented with CTM compared to SUL!:<. However, the effects on sole growth were not consistent throughout the entire 25-wk observation period, and CTM appeared to provide limited advantage over SULF for promoting growth of the hoof wall. TM source also had no effect on humoral immune response to a novel antigen or serum cobalamin. Additional study is needed to determine if amino acid complexes of Zn, Mn, and Cu would be more useful than inorganic TM for supporting sole growth in horses with compromised hoof quality, such as chronically thin-soled or laminitic horses.