2. Contagious Mastitis
Somatic cell count linear score1:
A somatic cell count linear score is a log2 transformation of the SCC score. Each one unit increase in the linear score is associated with a doubling of the somatic cell count, and an estimated loss of 1.5 pounds of milk production per day (6).
Purpose of somatic cell counts:
- Identify individual cows affected with subclinical mastitis.
- Monitor herd improvement after management changes are instituted.
- Identify herd mastitis problems as soon as possible.
Interpretation of somatic cell count linear score for an individual cow:
- 0 and 1: no evidence of subclinical mastitis
- 2 : low suspicion of subclinical mastitis
- 3 and 4: suspect for subclinical mastitis
- ≥ 5: subclinical mastitis
- 7 – 9: indicates that the cow is shedding extremely high numbers of somatic cells and is on the verge of showing signs of clinical mastitis.
A herd goal should be to have >80% of the animals with SCC linear scores ≤3.