In an IRT photograph of a group of cattle, the hooves of healthy animals appear blue-green, whereas infected cattle have orange-red feet. This easy visual distinction could allow scientists and veterinarians to identify potentially infected cattle in large groups without examining animals individually. The technology is cheaper and faster than existing screening methods, which involve individual clinical examinations for every animal.
http://www.ars.usda.gov/is/AR/archive/apr09/disease0409.htm