EVALUATING CHROMIC OXIDE SUSTAINED RELEASE PELLETS IN DIGESTIBILITY STUDIES WITH RUMINANTS

Abstract

Sustained release pellets were prepared containing chromic oxide (Cr2O3) as an indicator for digestibility studies using plaster of paris, portland cement, or china clay as binding agents. The pellets released the Cr2O3 at a constant rate in vitro but when placed in the reticulum of steers or wethers failed to mix uniformly with the reticulorumen contents. The percentage difference between the indicator method estimate and the total fecal collection method was 12.7 for estimating dry matter digestibility and 9.7 for energy digestibility. The percentage difference between the calculated and actual dry matter intake was 35.3. The sustained release pellets as prepared in this study are not satisfactory for administering the Cr2O3 indicator to estimate digestibility or feed intake.