Effect of Complexed Trace Mineral Supplementation on Joint Health in Young, Exercising Horses

Osteoarthritis has been named one of the major causes of lameness in horses, and remains one of the main reasons for performance loss. Nutritional interventions to prevent joint disease have not been investigated at length, and very little emphasis has been placed on the effects of trace mineral supplementation on joint health. To test the hypothesis that complexed trace minerals (CTM; Zn, Mn, Cu amino acid complexes and Co glucoheptonate) would benefit articular cartilage, sixteen Quarter Horse yearlings (9.1±0.17 mo) entering a submaximal exercise training program were balanced by age, sex, BW, and farm of origin, and randomly assigned to either CTM (n = 8) or inorganic (n = 8) dietary Cu, Zn, Mn, and Co for 12 wk. Horses had received their respective diets for 12 wk prior to trial initiation. Synovial fluid samples were collected at wk 0, 8, and 12 of exercise, and analyzed for concentrations of carboxypropeptide of type II collagen (CPII), and collagenase cleavage neoepitope of type II collagen (C2C), and chondroitin sulfate-846 (CS-846). Treatment differences were detected using PROC MIXED in SAS (v9.4) with diet, time, and diet × time interaction included as fixed effects and horse (diet) as a random effect. At wk 12, CPII was higher (P ≤ 0.0001), and C2C (P < 0.0001) and CS-846 (P = 0.005) were lower than at wk 0, but none were affected by diet in this study. The ratio of CPII:C2C, or synthesis to degradation, increased from wk 0 to 8 (P < 0.0001) in all horses but continued increasing to wk 12 (P = 0.015) in CTM horses. Dietary Cu, Zn, Mn, and Co source appears to enhance cartilage synthesis relative to degradation during low-intensity exercise training in young horses. Dietary CTM may lead to improved joint cartilage maintenance as the horse progresses through its performance career