Ground mushroom stumps (IMAGE) Penn State Caption Mushroom stumps for the research were obtained from a commercial mushroom farm in southwest Pennsylvania and transported to Penn State. Mushroom stumps were dried in a small grain drier and ground into appropriate size particles for inclusion in poultry feed. Credit Penn State Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.