Crop residues have high percentages of lignin, cellulose and hemicelluloses in a macromolecular complex and this intricate association makes a barrier to these lignocelluloses utilization by the livestock. Hence, they have poor digestibility, low in protein and palatability. When the soil fungi are employed for the biodelignification, the nutritive value of the straw improved remarkably but the voluntary intake of the treated straw is very low. Various types of edible white-rot fungi available in the market are used for biodelignification of straws. P.ostreatus is found to degrade about 18% of lignin, 20% of cellulose and 40% of hemicelluloses with only 10% loss in the dry matter of the straw. As a result the IVDMD of the straw improved by 60% and the protein percentage by 10 folds. The effect of various inorganic and organic feed additives on the nutritive value of the straw and delignification ability of the organism emphasized that the nutritive value of the treated straw has tremendously increased by the combined effect of chemical and fungal treatments.Feed formulations are made using fungal treated straw, cereals, mill byproducts and oil cakes in proper proportions.