FIBROSITY INDEX AS AN ESTIMATE OF FORAGE DIGESTIBILITY

Abstract

Twenty-one forages, covering a wide range of forage quality, were sampled at the Grange Research Centre during the spring and summer of 1983. Fibrosity Index (FI), a measure of the electrical energy required to mill the samples, was determined for each forage. In addition, in vitro dry matter digestibility (IVDMD) and modified acid detergent fiber (MADF) were determined on all samples. The regression of IVDMD on FI and of FI on MADF were significant with correlation coefficients of −0.91 and 0.91, respectively. FI was sensitive to small changes in both IVDMD and MADF. Because of the ease and rapidity of determining FI it should be a useful technique for screening materials from plant breeding programs or for field use.Key words: Fibrosity index, fiber, digestibility, forage quality