Bob Sager, DVM PhD DABVP (Beef Cattle) AAVN, has over 45 years of experience as a practicing veterinarian, including time as the senior veterinarian at the world's largest vertical integrated beef cattle complex, with over 437,000 head of Angus beef cattle. Sager has also taught Animal Science classes at Montana State University, and pioneered the understanding of the effects of cobalt on the immune system in beef cattle.