Excess of Molybdenum in Herbage as a Possible Contributory Factor in Equine Osteodystrophia

Abstract

DEFECTS in nutrition which predispose to osteodystrophic conditions in the horse include a dietary deficiency of phosphorus¹ or disturbance in the vitamin D – calcium – phosphorus relationship. With regard to the influence of trace minerals, Davis² found that the presence of small amounts of molybdenum, ranging from 2 to 25 p.p.m. in young growing herbage, was associated with defective bone metabolism in herbivora, consequent on the effects of molybdenum on the utilization of both phosphorus and copper. More recently, Arrington and Davis³ in limited phosphorus metabolism studies with rabbits reported that molybdenum decreased phosphorus absorption while at the same time increasing the excretion of phosphorus.