Environmental mastitis patterns in dairy cows

Find out how to measure infections and impliment control methods.

Why is environmental mastitis control important?

Control is very important for many herds, particularly those that control somatic cell counts (SCCs) and therefore significant contagious infection, as well as those that control dry period infections. 

Between 2009 and 2012, more than 90% of herds in the original DairyCo Mastitis Control Plan project showed environmental mastitis patterns. In 2018, only 8% of the AHDB Sentinel herds showed any indication of a contagious pattern.

Environmental mastitis in lactation pattern

Herds with environmental mastitis infections in lactation may see seasonal patterns and the impact of infections acquired from winter housing environments, pasture environments and/or the impact of heat stress and environmental infections during summer months.

The impact of new infections in lactation can be measured by looking at the SCC changes in cows between each milk recording.

KPI:

• No more than 5% of low cell count milking cows should move above the 200,000 cells/ml threshold between milk recordings in lactation

As well as monitoring new lactation infections by measuring changes in SCC between successive milk recordings, it is very important to monitor the rate of new clinical mastitis cases in cows that calved more than 30 days ago.

KPI:

• No more than 2 in 12 cows (or less than 16%) should be affected with a new case of clinical mastitis after 30 days of lactation

Environmental mastitis in dry period pattern

Herds with environmental mastitis infections in the dry period typically see an increase in cows and heifers calving down with mastitis and an increase in mastitis cases in the first 30 days after calving.

KPI:

• No more than 1 in 12 cows should be affected with a new case of clinical mastitis in the first 30 days of lactation

It is vital to monitor the outcome of dry period management in terms of new infections (cows dried off low cell count and heifers calving into the herd with high cell counts in the first 30 days of lactation).

KPI:

• No more than 10% of heifers should have a cell count of >200,000 cells/ml at the first milk recording after calving
• No more than 10% of cows that had an uninfected status at dry-off should have a cell count of >200,000 cells/ml at the first milk recording after calving

The California Milk Test can also be used to check all quarters of each cow for mastitis after calving. It is recommended to use the CMT on Day 4 after calving.

KPI:

• No more than 10% of cows should be CMT-positive at Day 4 after calving

Udder infections indicated by high cell counts typically cure over the dry period. However, herds with a dry period environmental problem may have a poor apparent cure rate over the dry period because cows that are infected at drying off may cure but become re-infected before they calve.

KPI:

• At least 85% of cows dried off with a high cell count (SCC >200,000 cells/ml) should have a cell count of below 200,000 cells/ml at the first milk recording after calving (i.e. they should cure over the dry period)

Further information