No replacement animals enter nor re-enter the herd. No replacement animals enter, but re-entry is allowed. Animals enter only with known medical records and isolation. Animals enter with known medical records but no isolation. New animals enter the herd with no medical records or isolation.
Dairies demonstrate willingness, ability to adopt.
Next to animals, people are the most common disease vector a biosecurity program must control. Clients growing their herds will require more purchased additions. Dairies buying replacements from wider sources. Increased local, national and international animal movement has increased the migration of diseases outside old bounds. Operations using an off-dairy professional heifer grower.