Abstract
The current work was carried out to investigate the biotechnological impact of different strains of fungi (Pleurotus Ostreatus , Trichoderma viride and Trichoderma reesei) and bacterial treatment by LAB (Lactobacillus Plantarum with or without addition of molasses) on the nutritive value of agricultural residues for production of good quality straw silage. Four types of straws namely rice straw (RS), bean straw (BS), mixture of rice and bean straw (RBS) and wheat straw (WS) were subjected to biological treatment under solid state fermentation) with each Microorganism. The experimental groups include, control group of each substrate which did not inoculated with any microorganism (CON) , and five treatments groups , T1 (straws treated by Lactobacillus plantarum with molasses), T2 (straws treated with lactobacillus plantarum without molasses), T3 (straws treated by Trichoderma viride ),T4 (Straws treated by pleurotus ostreatus ) and T5 (Straw treated by Trichoderma reesei). Each treatment was carried out for four types of straws. The results of proximate analysis showed increased crude protein, ether extract and ash contents in all treatment compared to the un treated straws .The biotechnological treatment also led to reduction in dry matter, organic matter, crude fiber and fiber fractions contents in all treatments relative to the control group. So it is recommended to treat agricultural residues by cellulosic fungi and bacteria especially Lactobacillus plantarum for improving its nutritive value for animal feeding. Further investigations are required in vivo to study the effect of feeding of the produced biomass on the performance of ruminants.

Key words: Biotechnology, Fungi, Bacteria, Nutritional value, Straws