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 Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Hardison, W. A. Articles by Graf, G. C. Search for Related Content PubMed Articles by Hardison, W. A. Articles by Graf, G. C.

Observations on the Use of Chromic Oxide for Estimating the Fecal Output of Dairy Animals¹

Departments of Dairy Science and of Biochemistry and Nutrition, Virginia Polytechnic Institute, Blacksburg

ABSTRACT

Two trials employing dairy heifers fed either fresh-cut alfalfa (Trial 1) or mixed hay (Trial 2), and one trial using lactating cows which received a complete ration, have been conducted to study further the usefulness of chromic oxide for predicting fecal output. Total fecal collections were made during each trial. In addition, partial fecal samples were obtained at 6 A.M., 12 NOON, 6 P.M., and 12 MIDNIGHT on each day of each collection period. The results indicate that periods of from three to seven days may be required for the indicator to reach a stable level in the feces. The mean recovery rates of chromic oxide from totally collected feces and from the combined 6 A.M. and 6 P.M. samples for Trials 1, 2, and 3, respectively, were 89.4 and 89.7%; 97.5 and 96.4%; 90.0 and 89.7%. Average daily fecal DM outgo was estimated from the chromic oxide concentration of the combined 6 A.M. and 6 P.M. samples, with an error of about 12%. Only in Trial 2 were satisfactory estimates obtained.

¹ Contributing to Regional Project S12.

² Deceased.