COMPARISON OF CELLULASE SOLUTIONS FOR USE IN DIGESTING FORAGE SAMPLES

Prepared cellulase solutions from different origins may differ in their relative effectiveness in providing accurate estimates of in vitro dry matter digestibility (IVDMD) of forages. Our objectives were to compare prepared cellulase solutions from different commercial sources with our non-commercial prepared cellulase solution and evaluate their effectiveness in obtaining meaningful estimates of IVDMD for three grass and three legume species. A total of 46 samples were evaluated from six different forage species including switchgrass (Panicum virgatum L.), big bluestem (Andropogon gerardii Vitman), tall fescue (Festuca arundinacea Schreb.), alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus corniculatus L.), and lespedeza (Kummerowia Thunb.). Significant differences for IVDMD were found among the prepared cellulase solution sources. Correlations between IVDMD estimates using the prepared cellulase solutions and in vitro rumen fermentation ranged from 0.57 to 0.95. The highest correlation (r = 0.95) was observed using a non-commercial prepared cellulase solution and the next (r = 0.91) was obtained from cellulase procured from Worthington Biochemical Corp (Freehold, NJ). We concluded that the cellulase solution prepared from cellulase obtained from Worthington Biochemical Corp. was an alternative to our non-commercial source in obtaining estimates of IVDMD.