Dear Dr. Fayaz in the Dominican Republic produces more than 18 million chickens per month and all use enzymes: proteases, xylanases, amylases, phytases and beta-glucanases the results and the return on investment are excellent.
In practice there is no real study on the use of Cellulases in poultry diets, Cellulose has different molecular configurations (4 types are recognized) therefore there is a need for a complex cascade of enzymes, not only cellulase but other enzymes that also work on the cellulose ligning interactions (Lacases from white rot fungi are good examples). Therefore, I would be surprised if we could have a Cellulase that works in anaerobic conditions, that is thermostable and will survive up to the large intestine or ceca of monogastric animals.
To circumvent this, companies are looking at solid state fermentation of low nutritional value raw materials (Soybean and Sunflower husks, palm kernel meal, etc.).
At my current position, I have been looking at the use of enzymes and other silage additives to improve the nutrient value of raw materials available in tropical regions.