ToolsBulk tank SCC
This PropelMapper calculator weights each cow’s somatic cell count by her milk to estimate the bulk tank figure.
Enter cow ID, SCC in thousands of cells/mL and milk amount, separated by commas or tabs. Use 250 for 250,000 cells/mL. Keep one milk unit throughout; do not add thousands separators inside numbers.
The twelve starting cow entries are fictional. The calculation describes only the milk included in the mixture you enter.
| Measure | Result |
|---|---|
| Bulk tank SCC, milk-weightedΣ (SCC × milk) ÷ Σ milk | 229,000 cells/mL |
| Cows over 200,000 | 4 of 12 cows |
| Cells from the top three cowsThe three cows with the most cells | 66 % of the tank |
| The tank without those three | 97,000 cells/mL |
You are preparing for a herd visit and have cow test-day counts with their milk amounts. You enter matching collection periods here to estimate the mixture those rows describe. A larger milk contribution carries more weight in the result.
You record the calculated figure with the cow IDs, dates and milk included. In the visit note, you can explain why this mixture may differ from the milk behind a laboratory tank result.
After upload, we can include that note in the report you read and send to the producer. Your veterinary interpretation and advice come from you; the calculation only describes the mixture you entered.
“The twelve example cow records give about 229,370 cells per milliliter when weighted by their milk amounts. I am recording the included cows and collection period with this estimate. It is a calculated mixture, not a tank test.”
The twelve example cow records produce a milk-weighted estimate of about 229,370 cells/mL.
The included cows, milk amounts and collection period define this estimate. It is separate from a laboratory tank result.
The twelve example cow records produce a milk-weighted estimate of about 229,370 cells/mL.
The included cows, milk amounts and collection period define this estimate. It is separate from a laboratory tank result.
After your review
The calculation multiplies each cow’s SCC by her milk amount, adds those products and divides by total milk. Pounds or kilograms work for weighting if you use the same unit on every row. Match the SCC and milk collection periods.
The count above 200,000 cells/mL uses Penn State’s reference level for further evaluation. Discuss its interpretation with the herd veterinarian. Removing rows recalculates a different mixture; it does not predict treatment response or determine milk withholding.
In the twelve fictional records, multiplying each SCC by its milk amount and adding the results gives 233,957. Divide by the total milk amount, 1,020, to get about 229.37 thousand cells/mL.