Mastitis: Introduction

Mastitis is on of the most prominent and common diseases of dairy cattle in the United States. Mastitis not only affects animal health and well being it can have major implications on the profitability and financial health of the dairy. Milk quality is also profoundly affected by the level of both clinical and sub clinical mastitis in a herd. Bulk tank milk SCC and bacteria levels are regulated by state and federal agencies to ensure food safety issues and protect consumers. Mastitis is important to processors since milk quality is directly correlated to cheese yield, product shelf life and quality.

Recent (1998) research from the Quality Milk Promotions Services program at Cornell demonstrated that nearly half of all the cultures from New York and Pennsylvania herds participating in their program were positive for some mastitis pathogen. When that information was applied to herds enrolled in DHI 36% were positive for some major mastitis pathogen. Despite major improvement in mastitis’s control programs and treatment mastitis is still a common and costly disease of dairy cattle.

Organisms that cause mastitis can be classified as environmental or contagious by nature. All dairy farms incur losses from environmental infections. Environmental infections are often the predominant type of mastitis on modern well managed farms. Infections can be controlled and reduced by identifying and addressing the specific risk factors that are present on the farm. Contagious mastitis is caused by specific contagious organisms and infection is transmitted to susceptible animals during the milking process. Contagious mastitis is best controlled with specific milking time procedures designed to prevent cow to cow transmission of infection. Those procedures include segregation, hygiene, culling and treatment. Major contagious mastitis pathogens can be eliminated from herds

Mastitis control and prevention should be ongoing procedures on all dairy farms. Establishing goals for mastitis and milk quality should be a part of every farm plan. Issues such as the number of clinical cases, treatment outcome, bulk tank SCC, etc. should be monitored on a regular basis. When established benchmarks are exceeded herd management must react quickly to assess the potential risk factors and correct the problem immediately.