Duff et al., 1993. J. Anim. Sci., 71 (1): 29 Document reference Duff, G. C.; Galyean, M. L.; Malcolm-Callis, K. J., 1993. Intake and ruminal fermentation by beef steers consuming prairie hay with supplements containing corn, soybean hulls and urea. J. Anim. Sci., 71 (1): 29Citation key Duff et al., 1993Datasheets Soybean hulls