Feed costs account for large part of the total costs in milk production. Thus, dairy producers attempt to minimize the costs of feeding their herds particularly when milk prices are low. By-product feeds such as soybean hulls, In addition to the potential of providing an economical alternative, can be successfully used as a source of fiber in rations for dairy cattle when forages have poor quality or are in short supply (Firkins, 1997; Weidner and Grant, 1994). Alternatively, replacing cereal grains with SH in diets for dairy cows may contribute to elevated intakes of energy while preventing a disruption of rumen functionality (Ipharraguerre et al., 2003). The objectives of this paper are to evaluate effects of soybean hulls in replacement of alfalfa hay, corn silage and wheat bran on performance and total tract apparent nutrients digestibility.