Chromic oxide in range nutrition studies

Published September 1980. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalogA variety of studies were conducted by some 13 states and agencies to\ud attempt to validate or develop parameters for using chromic oxide to determine\ud intake and digestibility of the grazing ruminant animal.\ud Recovery trials were conducted under a variety of experimental conditions,\ud ranging from confinement to grazing trials under range conditions. Included\ud in these studies were various methods of and carriers for administration of\ud the chromic oxide to the animal.\ud The diurnal variation of excretion of chromic oxide to determine time or\ud number of administrations per day and established sampling time were evaluated.\ud Methods of administration were further evaluated as to their effect on diurnal\ud variation. Among methods used were the pure form of chromic oxide, paper\ud impregnated chromic oxide, "solka floc" or cellulose-chromic oxide boluses,\ud various modifications of a sustained release chromic oxide, and foliar application\ud of chromic oxide.\ud The various "systems" of using chromic oxide to estimate fecal output\ud and forage intake and digestibility were evaluated with different classes of\ud animals and levels of production in with varying conditions in the western\ud states. The use of chromic oxide as an external indicator in range nutrition\ud will have limitations, but these data will help define those parameters.\ud Guidelines or recommendations, for planning research and interpreting the\ud results from chromic oxide studies are presented