A note on the use of chromic oxide incorporated in a feed to estimate faecal output in ruminants

Abstract
Chromic oxide (Cr2O3) has been used for some time as an inert marker to estimate the faecal output of livestock. Although several methods of administration have been reported (Grassland Research Institute, 1961) the more widely used form would appear to be that of purchased gelatin capsules containing a suspension of Cr2O3 in maize oil. An alternative is to include the Cr2O3 in a concentrated feeding stuff. This method was widely used by early workers (e.g. Edin, Kihlén and Nordfeldt, 1944).