Particulate Matter Rate Of Passage In The Rumen Of Beef Cattle

Abstract

The process that limits the rate at which particulate matter exits the reticulorumen is believed to be either the rate at which large particles are broken down to small particles or the rate at which small particles exit the reticulorumen. Dysprosium was bound to large particles and its ruminal concentration was used to predict the rate of large particle breakdown. Ytterbium was bound to small particles and this ruminal concentration was used to predict exit rate. Statistical analysis of data indicated that there was no significant difference between the percent per hour turnover values for ytterbium-and dysprosium-labeled particles. It appears that large particles may be broken down to small particles at the same rate that small particles exit the reticulormen. Particulate matter turnover rates produced by administer ing a pulse dose of erbium and by ruminal manual evacuation show statistical correlation. In order to achieve mathematical correlation between predicted particulate matter turnover rates and observed particulate matter turnover rates, it is advisable to feed the subjects more than once a day, and perhaps to obtain better correlation, to feed at frequent intervals throughout a 24-hour period.