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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Colucci, P. E. Articles by McMillan, I. Search for Related Content PubMed PubMed Citation Articles by Colucci, P. E. Articles by McMillan, I.

Comparative Digestion in Sheep and Cattle Fed Different Forage to Concentrate Ratios at High and Low Intakes

University of Guelph, Guelph, Ontario, Canada N1G 2W1

ABSTRACT

Effect of maintenance and ad libitum intakes on digestibility of different feed fractions was studied with six ruminally fistulated cows and six ruminally fistulated wethers to validate the use of sheep as a model for cattle. Complete diets were made up of ratios of alfalfa:cracked corn and soybean meal of 80:20, 55:45, and 30:70. The regression coefficient of the line relating organic matter digestibility with proportion of concentrate in the diet was smaller for the cows at ad libitum intake than for the other groups. Increasing the intake caused a decrease in digestibility of different fractions. The depression in digestibility was greater for the 30:70 forage:concentrate diet than for the others. At high intake, digestion values in the cows were less than those in the sheep for all diets. An increase in intake depressed the digestion of cell wall fractions and cell solubles including starch in cows, whereas in sheep, an increase in intake reduced cell wall digestion and to a lesser extent cell solubles, without affecting starch digestion. The digestive physiology of these species is sufficiently different to preclude the use of sheep data in formulating nutrient requirements for cows.

¹ Department of Animal and Poultry Science.

² Department of Biomedical Sciences.

This article has been cited by other articles:

				W. P. Weiss and D. J. Wyatt Digestible Energy Values of Diets with Different Fat Supplements when Fed to Lactating Dairy Cows J Dairy Sci, May 1, 2004; 87(5): 1446 - 1454. [Abstract] [Full Text] [PDF]