HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Miller, P. A. Articles by Lawrence, L. M. Search for Related Content PubMed PubMed Citation Articles by Miller, P. A. Articles by Lawrence, L. M.

The Effect of Dietary Protein Level on Exercising Horses

University of Illinois¹, Urbana 61801

Abstract

Six mature Quarter Horse mares were used in a crossover design to assess the effect of dietary protein level on metabolic response to exercise. After a 2-wk adaptation period to either a 12.9% (control) or an 18.5% CP (high-protein) diet, each mare performed a standard exercise test. The test consisted of a 15-min exercise period at 4.5 m/sec on a 9% grade motorized treadmill. Exercise resulted in an increase in heart rate (P < .001), but there was no difference (P > .05) between dietary treatments. In the jugular vein, lactate increased (P < .01) from 6.3 to 52.0 mg/100 ml in the control group and increased from 6.3 to 45.6 mg/100 ml in the high-protein group. There was an interaction (P < .05) between diet and exercise for lactate. Plasma NH₃ increased (P < .001) during exercise, but not until the 15th min, at which time NH₃ increased over fourfold in both groups. Dietary protein did not affect NH₃; however, urea-N was higher (P < .001) in horses receiving the high-protein diet. Plasma alanine increased from 13.6 to 30.3 µmol/100 ml and glutamine increased from 49.3 to 62.5 µmol/100 ml in the control group. In the high-protein group, alanine increased from 10.2 to 25.8 µmol/100 ml, whereas glutamine increased from 39.3 to 49.2,µmol/100 ml. Our study detected no metabolic evidence for a detrimental effect of excess dietary protein in horses exercising on a graded treadmill at 4.5 m/sec for 15 min.

¹ Dept. of Anim. Sci.