Concentration of minerals in the hoof horny capsule of healthy and lame dairy cows

Abstract

The aim of this study was to evaluate the mineral concentrations in the hoof horny capsule of healthy Holstein cows and cows with hoof problems associated with laminitis. Twenty-one multiparous Holstein cows with an average production of 24 L of milk/day, reared with semi-extensive nutritional management, were studied. The animals were evaluated and divided into two groups based on their locomotion score (LS, range: 0 to 4). LS greater than 2 indicated laminitis-associated lesions (lame cow group: LC), and LS = 0 indicated cows without laminitis (CWL). A sample of 30 mm2 was collected from the hoof horny capsule at the abaxial wall to evaluate the concentrations of calcium, phosphorus, zinc, and magnesium. Calcium blood concentration was also evaluated. The LC group had lower magnesium concentration (P=0.008) and showed a trend (P=0.06) for lower calcium concentration compared to healthy animals (CWL), even though all animals were normocalcemic. The concentration of other minerals did not differ between the LC and CWL group. In conclusion, the magnesium concentration in the hoof horny capsule was lower in cows with lesions associated with laminitis, while phosphorus and zinc concentrations were not affected. The relationship between hoof lesions and calcium concentration requires further investigation.