Sugarcane bagasse and pith, by-product which the residue after rind removal, are highly lignified by products of the sugar and paper industries, are the most abundant by-product in Iran. The use of by-product in animal nutrition is necessity since it may increase the availability of feed for animal and avoid accumulation that contributes to environmental problems. The main nutritional constraints for these crop residues as animal feeds are their slow rate of digestion and low nitrogen content (Liu et al., 2000). Steam-pressure treatment cleavage the bounds between lignin and the other component of the cell wall, in order to improve it’s degradability by enzymes of the rumen microbial ecosystem. The aim of this study were to evaluate the effect of increasing dietary steam treated pith content on feed intake, milk yield and composition of lactating dairy saanen goats.