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 Haenlein, G. F. W. Articles by Yoon, Y. M. Search for Related Content PubMed Articles by Haenlein, G. F. W. Articles by Yoon, Y. M.

Determination of the Fecal Excretion Rate 0f Horses with Chromic Oxide^{1, 2,}

University of Delaware, Newark

Abstract

The diurnal variation in the excretion of chromic oxide (Cr₂O₃) was studied in six horses during three digestion trials, using one lot of alfalfa hay in three physical forms (chopped loose, pellets and wafers). The recovery of Cr₂O₃ averaged 98.4%. The intraday variation of Cr₂O₃ ranged from 59.8 to 134.8% of the daily mean among defecations of individual horses. The proximate fecal constituents varied less than Cr₂O₃ and in the descending order of ash, water, crude protein and crude fiber. Their variance did not seem to be related to that of Cr₂O₃. The interday variation of Cr₂O₃ and fecal constituents was as great as the intraday variation.

Fecal Cr₂O₃ concentrations varied in a diurnal pattern described by a fourth degree polynomial equation for separate day and night periods. Approximately 64 and 89% of the variation was explained by the mean day and mean night curves, respectively. A sixth degree polynomial accounted for 76% of the variation of the mean day plus night combined curve. The Cr₂O₃ excretion curve was best described by a sinusoidal periodic function, for which the Fourier coefficients were calculated for two harmonics. The time after administration of Cr₂O₃ to the horses appeared to be the major determinant for the extinction of the excretion curve, but the night curve showed a higher extinction than the day curve. The phase of the curves was moved when either pellets, wafers or loose hay were fed, indicating a different rate of passage of Cr₂O₃ with different physical forms. Estimates of fecal excretion rates of horses by the 4-day rectal grab sample method and determination of Cr₂CO₃ content were similar to results from the 10-day total collection procedure, provided that recovery rate of Cr₂O₃ was considered. Fecal Cr₂O₃ samples taken at random for 10 days provided estimates of fecal excretion rates which did not agree with those from the total collection procedures.

¹ Department of Animal Science and Agricultural Biochemistry. Published as Miscellaneous Paper No. 499 of the Delaware Agricultural Experiment Station with the approval of the Director.

² Assistance of the following persons is gratefully acknowledged: R. Pigford, Mrs. E. R. Haenlein, C. Zeitler, W. Alfree and R. M. Somers.

³ Department of Agricultural Economics.

⁴ Present Address: Air Reduction Chemical and Carbide Company, Bound Brook Laboratories, Bound Brook, New Jersey.