Emerging Mastitis Threats on the Dairy

Introduction Mastitis is the most frequent and costly disease of dairy cattle. Losses due to mastitis can be attributed to both subclinical and clinical disease. Clinical mastitis losses are generally readily apparent and consist of discarded milk, transient reductions in milk yield and premature culling (Fetrow, 2000). Subclinical mastitis is considered the most economically important type of mastitis because of long term effects of chronic infections. Production losses due to subclinical mastitis on U.S. dairy farms were estimated to cost the dairy industry $1 billion dollars annually (Ott, 1999). Mastitis is a concern of most dairy farmers and their advisors due to these profound economic consequences.