Researcher Leoni Martins in dairy barn (IMAGE) Penn State Caption Researcher Leoni Martins, doctoral student in the Department of Animal Science, led a 10-week experiment that included 48 Holstein cows. He is pictured here with a cow in the Penn State Dairy Barns 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.