Evaluate the effectiveness of this program and make any adjustments if necessary. Only purchase cattle from herds with a known health status. Require a health history on purchased cattle. Ask for the DHIA somatic cell count information on milking cows. Check for evidence of contagious mastitis in current and previous lactations.
Heifers are preferable to lactation cows.
They are easier to Quarantine and less likely to have contagious mastits. Open heifers are an even better choice, since they allow you more control and options in vaccinations over bred heifers. Test and quarantine new herd dditions. Test all purchased cattle for BVD virus, Johne's disease, bovine leukosis, and mastitis caused by Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma bovis. Quarantine alone will not protect your herd against the above mentioned pathogens.