Improving udder health takes more than treating individual cases of mastitis. It requires a clear plan, regular check-ins, and measurable goals. For many farms, finding the time to step back and evaluate herd performance feels nearly impossible—especially when staff and owners are busy with daily work. However, setting aside even a few hours each quarter can make a meaningful difference in milk quality and long-term herd health.
A strong management plan is built on a cycle of five ongoing steps:
-
assess performance,
-
set specific goals,
-
create a plan to reach those goals,
-
assign responsibilities, and
-
evaluate progress.
Repeating this cycle throughout the year helps farms stay focused, catch problems early, and make continuous improvements.
Using Bulk Tank Somatic Cell Count (BTSCC) to Monitor Herd Health
Bulk tank somatic cell count is one of the most useful indicators of overall udder health. It measures the quality of the milk sold from the farm, but it does not include milk from cows with clinical mastitis, abnormal milk, or cows under antibiotic withdrawal. Because of this, the BTSCC reflects the health of the cows contributing to the tank—mainly those with normal milk.
A rising BTSCC often signals that subclinical mastitis is becoming more common in the herd. Unlike clinical cases, subclinical mastitis does not change the appearance of the milk or udder, so BTSCC becomes an early warning sign.
Industry guidelines have become more stringent over time. Today, most farms can realistically aim for a BTSCC of under 200,000 cells/mL. When BTSCC begins to climb, it is important to look at individual cow monthly records, especially to identify cows with chronic infections. These cows maintain high somatic cell counts for two months or more, quietly elevating the bulk tank number.
Key Performance Indicators for Subclinical Mastitis
To understand what is driving BTSCC changes, farms should track monthly somatic cell count (SCC) data. Three simple performance indicators provide a clear picture of subclinical mastitis in the herd:
1. Prevalence – How many cows currently have subclinical mastitis?
To calculate prevalence:
-
Count the cows with SCC over 200,000 cells/mL this month.
-
Divide by the total number of cows in the herd.
This number shows how widespread subclinical mastitis is at any given time. The goal is to keep prevalence at or below 15%.
2. Incidence – How many new infections developed this month?
To calculate incidence:
-
Count the cows with SCC over 200,000 cells/mL this month.
-
Divide by the number of cows that were below 200,000 cells/mL last month.
This shows how well your prevention strategies are working from month to month. The goal is to keep incidence at or below 8%.
3. Fresh Cow Mastitis Rate – How many cows start lactation with elevated SCC?
To calculate this rate:
-
Count fresh cows (in their first month of lactation) with SCC over 200,000 cells/mL.
-
Divide by the total number of fresh cows.
This metric reflects the quality of your dry-off program and calving-period management.
Recommended goals:
-
10% or less of first-lactation cows
-
15% or less of cows in their second or later lactation
If a high percentage of fresh cows enter the tank with elevated SCC, it may indicate issues in dry cow housing, bedding, hygiene, or teat-end condition at dry-off.
Putting It All Together in Your Management Plan
A mastitis management plan becomes most effective when these indicators are reviewed regularly—ideally each month, with a deeper evaluation every quarter. Tracking trends over time helps farms:
-
identify early increases in infection pressure,
-
understand whether prevention strategies are working,
-
target problem groups such as chronically infected cows or fresh cows, and
-
set clear improvement goals for the next quarter.
Because the management cycle is continuous, even small changes—like improving bedding frequency, adjusting milking protocols, or reviewing cull decisions for chronic cows—can yield significant improvements in milk quality.
Bottom Line
Creating a mastitis management plan does not need to be complicated. By setting time aside, focusing on a few key indicators, and reviewing progress throughout the year, dairy farms can strengthen milk quality, improve herd health, and maintain a BTSCC below 200,000 cells/mL.
