Influence of month, color, age, corticosteroids, and dietary molybdenum on mineral concentration of equine hair
Cape, L.; Hintz, H.F.
American Journal of Veterinary Research 43(7): 1132-1136
1982
ISSN/ISBN: 0002-9645 PMID: 7103191 Document Number: 193906
A series of trials was conducted to study the effects of several factors on mineral concentration of hair of horses and ponies. Samples were taken monthly (Oct.-Jan.) from mature pinto ponies, from young ponies fed diets containing molybdenum (Mo; 3 or 50 mg/kg of feed), and from young horses given daily placebo or dexamethasone injections (5 mg/100 kg of body wt). Colored hair taken from pinto ponies had higher concentrations of Ca (P < 0.09) and P (P < 0.08) than did white hair taken from the same ponies. The Mo, Cu, and Fe concentrations were similar in both colors of hair. Month of collection influenced the hair content of all minerals, except Mo. Hair Ca concentration decreased (P < 0.004) during the study period in the 3 groups of animals, but remained constant in the white hair of the pinto ponies. The results for Cu, Fe and P were not uniform in the 3 groups of animals. Hair Cu concentration decreased (P < 0.05) in the young horses, hair Fe concentration decreased (P < 0.03) in the young ponies, and hair P concentration decreased (P < 0.0001) in the mature pinto ponies. In all other cases, the hair Cu, Fe and P concentrations remained constant. Age affected hair Fe concentration, which was significantly lower in the young ponies than in the mature pinto ponies in Nov. (P < 0.025) and Dec. (P < 0.03). Hair Mo and Cu concentrations were not influenced by age. The results for hair P are inconclusive. Excess dietary Mo increased (P < 0.02) hair Mo concentration, but did not influence concentrations of Fe or Cu. A conclusion could not be made concerning the effect of Mo on hair P or Ca. Dexamethasone injections decreased (P < 0.06) hair P concentration and increased (P < 0.09) Cu concentration, but did not influence Fe and Ca concentrations. Several factors influence the mineral composition of hair. They must be better characterized before hair concentrations of minerals are used as determinants of the nutritional status of equids.