been used to wash out pathogenic bacteria. When abnormal bacteria are observed, stray voltage should be checked by an electrician and the power-company representative. Common causes are 120-volt motors, static electricity, off-farm voltage leak and ungrounded motors. New construction should have a grid installed beneath the floor to prevent stray voltage from grounding through the cow. Use well-grounded 220-volt motors in all areas where possible to keep both 110 legs of the incoming service balanced and reduce the likelihood of voltage drift. Sheet iron roofing generates more static electricity during windy conditions.
Summary
Producing milk with low somatic cell counts is a necessary and profitable management tool. Maintaining healthy cows through proper nutrition is the first requirement. Practices contributing the most to decreasing SCC are controlling mastitis and culling cows with a high SCC count. Records maintained by DHI with SCC contribute to profit by monitoring results of management procedures that decrease exposure of teat-ends to pathogens.
Proper milking practices including teat dipping, sanitary management and dry cow therapy based on cultures of individual quarters are the most important components of a mastitis control program. Lowering somatic cell count from 600,000 to 300,000 increases milk sales by $50 per cow per year, which is a small fraction of the total benefit. Some milk processors have incentive payments for lowering SCC in milk.
Always use legal medication to treat cows with mastitis and then withdraw the milk from market for the required time.