Effect of Age and Dietary Magnesium on Voluntary Feed Intake and Plasma Magnesium in Ruminants

Abstract

The relationship in ruminants between plasma magnesium and voluntary feed intake as influenced by age of animal and by dietary magnesium was studied with six wethers per age group classified as lambs (6 to 12 mo), yearlings (1 to 2 yr), and adult sheep (2 to 3 yr). Plasma magnesium decreased more quickly, and voluntary feed intake was reduced sooner in the mature sheep than in the younger animals when a diet low in magnesium was fed. With a purified diet containing no supplemental magnesium, voluntary feed intake and plasma magnesium were correlated: lambs, .60; yearlings, .72; and adult sheep, .58. © 1973, American Dairy Science Association. All rights reserved.