The use of chromium oxide and lignin as indicators for the purpose of determining intake and digestibility of mixed rations by beef steers

Abstract

During the winter of 1956, an experiment was conducted, using seventy beef steers of three different age-groups to determine intake and digestibility, by means of the indicator method, of mixed rations differing in ration concentration.In the first part of the experiment, six pairs of steers of three age-groups receiving two types of rations were used. The pairs were selected on the basis of their rate of gain and constituted the fastest and slowest gaining steers of their respective age and ration groups. The object of the experiment was to ascertain whether any correlation could be found between the rate of gain of the steers and the degree to which the ration was digested.Two indicators were used, namely, the internal indicator lignin and Cr2O3, administered twice daily by means of gelatin capsules, containing 7·5 g. of the indicator.Using lignin as an indicator of digestibility, it was found that the calculated digestibility coefficient of both rations varied. A larger variation occurred, however, in the case of the ration with a concentrate to roughage ratio of 2:1 than in the case of the ration with a ratio of 1:3·6.