Magnesium, Calcium and Phosphorus Metabolism in Ponies Fed Varying Levels of Magnesium

Abstract

A 3 × 3 latin square design balance trial was conducted with three mature ponies fed diets containing 0.16, 0.31 or 0.86% magnesium. Increasing the dietary level of Mg increased Ca absorption but did not affect P absorption. Increasing the Mg intake increased Mg retention, urinary losses and apparent and true digestibility of magnesium. Estimated endogenous fecal and urinary Mg losses were 2.2 mg and 3.9 mg of Mg/kg of body weight, respectively. The maintenance requirement for ponies was estimated to be 12.8 mg Mg/kg of body weight. Copyright © 1973. American Society of Animal Science. Copyright 1973 by American Society of Animal Science.