The course of some bone remodelling plasma metabolites in healthy horses and in horses offered a calcium-deficient diet.

The study investigates how plasma metabolites, which are associated with bone remodelling, behave in healthy horses and horses given diets deficient in calcium. The researchers specifically assessed variations in these metabolites when unbalanced diets were administered and later corrected in certain horses.

Study Design and Participants

• The study involved 21 Warmblood saddle horses (aged 4-26 years), five Ardennes draught horses (aged 4-10 years), and ten Ardennes foals (aged 9-11 months).
• The horses were fed according to regular feeding practices in Belgium.

Metabolites in Focus

• The metabolites in question relate to bone formation and resorption. Bone formation metabolites include bone alkaline phosphatase (BALP), total alkaline phosphatase (TALP) and osteocalcin (OC), while bone resorption was assessed by hydroxyproline (HYP).
• The study also observed concentrations of total calcium, ionized calcium, phosphorus, and 25-hydroxyvitamin D3, which were found to be more or less constant.

Findings

• The results showed a decrease in bone marker concentrations with age.
• The comparison of bone remodelling factors between Ardennes and Warmblood horses showed higher concentrations in the Ardennes breed.
• Correcting an unbalanced calcium-to-phosphorus (Ca : P) diet led to inconsistent effects on the plasma level.

Interpretation and Implications

• The researchers found interpreting different bone parameters to be difficult without associating them with other factors. These include a comprehensive history (anamnesis) and clinical examination of the animal, along with dietary evaluation.
• The study provides insight into how unbalanced diets, particularly those deficient in calcium, can affect horses’ bone health, and points to the importance of assessing multiple factors in understanding horses’ overall health and nutritional needs.