Prime Mastitis is a ratio that compares a single cow's mastitis measurement against her own measurement from 7 days ago. A ratio of 1 indicates no change in measurements and she is unlikely to be infected. The higher the ratio, the higher the possibility of infection. The acceptable range of measurements is 0.95 - 1.05.
Once you have got your BMSCC to where you want it and there are no high cell count cows left in the herd, you can maintain your low BMSCC by looking for cows who have had their mastitis and yield measurements change. Using Prime Mastitis and Yield 2weeks is very helpful to monitor changes. No change in Prime Mastitis indicates infection levels are constant. An increase in Prime Mastitis indicates a likely new infection. In some cases the infection may effectively block the quarter which may result in a decrease. A drop in Yield 2weeks often indicates a likely infection.
The number of cows to screen for change can vary from herd to herd. A good starting point is to look at cows that have a Prime Mastitis ratio above 1.05. Sometimes teat ends will be completely blocked which will result in a decrease in Prime Mastitis and you may want to try a value below 0.95. This process should be used to screen your cows twice a week.
The Mastitis Change Report has useful information such as the Prime Mastitis ratio, Mastitis ratio, Yield 2weeks, Time last seen (when the cow was last seen in the shed) and Days in Season (number of days in lactation). The example below looks at filtering cows with a Prime Mastitis ratio above 1.05.
1. Go to Summary Reports > More Reports
2. Under the Health heading select Mastitis Change Report
3. Click on Add Criteria
4. Under Which Column select Prime Mastitis
5. In the next drop down select greater than or equals
6. Type 1.05 in the Value box
7. Click Add
8. Optional: Select all cows by clicking on the box next to Actions and choose either to draft the cows at Inshed Action or click on Group Membership to put them in a group.
Introduction - Managing your BMSCC with MilkHub
Stage One - Using the Mastitis Ratio (Getting your BMSCC under control)