Research shows that the greatest proportion of antimicrobial treatments in dairy herds is due to clinical mastitis.

University of Wisconsin milk quality specialists recently reported the results of a study involving antimicrobial usage on large dairy herds in Wisconsin. The results, reported at the 3rd International Symposium on Mastitis and Milk Quality, in St. Louis, Mo., show that all farms involved in the study treated cows for clinical mastitis using antimicrobial drugs. There was variation in the proportion of treatments among farms. However, most farms ranged from 10 to 40 treatments per 100 lactating cows during a one-year period. The most common intramammary treatment used was ceftiofur (60 percent), followed by cephapirin.

Successful clinical mastitis treatments are influenced by a variety of factors including cow factors, pathogens, and treatment protocols.

According to this study and several others, the following factors should be considered when making treatment decisions: somatic cell count, evidence of a previous clinical case, parity, stage of lactation, number of mastitis cases in the present lactation, type of pathogen causing the infection, antimicrobial compound and duration of treatment. Attention to these factors improves cure rate and decreases antimicrobial usage on cases that do not respond to treatment.

Source: University of Wisconsin Milk Quality Web site