Investigations on the composition of horse bones

Abstract

Specific gravity and the content of dry matter, crude protein, ash, major minerals as well as trace elements were determined in the rostral process of the nasal bone, the rib, the caudal vertebrae and the cannon bone in 50 horses of different age. In contrast to the skeleton of other domestic animals, the horse skeleton showed a lower magnesium concentration, a tendency towards higher calcium content and a wider ratio of calcium to phosphorus. Dry matter and ash content increased from birth up to the age of 60 months while the crude protein content decreased. The calcium content increased with age to a considerable degree but the phosphorus content only to a small amount, so the ratio of calcium to phosphorus increased as well. The magnesium, potassium and chlorine content decreased with increasing age while the zinc content did not show any relation to age. The copper content increased until the age of 8 years and thereafter decreased again. The lead content of the skeleton depended on age and exposure (contamination of the living area). The lead content of the caudal vertebrae was highly correlated with the lead content of the other bones of the same horse investigated (r=≥0.96**). For the estimation of age the specific gravity of the cannon bone is best suited (r=0.92**). A post mortum diagnosis of magnesium, potassium or zinc deficiency should be possible by analysis of the caudal vertebrae because the content of this bone is strongly related to that of the other bones and the concentration of these elements is also related to the intake. For the estimation of the sodium supply only the rib or the cannon bone should be used. The calcium content of the cannon bone was closely related to the concentration in the caudal vertebrae (r=0.73**).