Avoid buying a replacement cow with a mastitis history. One of the most common ways to introduce cow-associated mastitis bacteria into a herd is in the udders of newly purchased cattle. Before introducing cows into a herd, obtain as much information as possible about the mastitis status of the farm of origin.

Bulk milk cell count records, individual cell counts, and records of clinical cases are helpful in assessing the potential risk new cows pose to the existing herd. Cattle should not be purchased from vendors who are unwilling or unable to provide this information.

Older cows are more likely to carry mastitis than younger cows.  If possible, it is preferable to buy unmilked heifers because they are much less likely to be carrying any of the major bacteria that cause mastitis. 

If you are buying cows, ensure they come from herds with Bulk Milk Cell Counts below 200,000 cells/mL, and have individual cell counts below 250,000 cells/mL.  As an added precaution it is a good idea to milk the new cows last until you are confident they are free from mastitis.

Don’t forget to obtain the Dry Cow Treatment details for dry cows you purchase, so you know the correct withholding periods to avoid antibiotic residues.  If you are unsure, contact your dairy company to organise screening tests.

Countdown Downunder Farm Guideline or Technote
Farm Guideline Introduction, 21, Technote 21

Keywords
Buying cattle, clinical cases, BMCC, ICCC, antibiotics