Table 26.
Common measures used for assessment of mastitis
| Indicator group | Variable | Methods | Reference |
|---|---|---|---|
| Bacterial culture | Identification of a mastitis pathogen | Based on aseptic quarter milk samples | Duse et al. (2021) |
| Bacterial culture | Identification of a mastitis pathogen | Based on bulk milk samples | Bauman et al. (2018) |
| Clinical Mastitis | Cases of cm/cows at risk | Veterinary diagnoses/treatments based on farm records | Bradley et al. (2007) |
| Clinical Mastitis | Cases of CM/cows at risk | Veterinary diagnoses/treatments based on national databases | Osteras et al. (2007) |
| Clinical Mastitis | Cases of CM/cows at risk | Including severity of clinical signs: (a) mild: only abnormal milk; (b) moderate: abnormal milk with swelling or redness of mammary gland; (c) severe: includes systemic signs of illness such as apathy, anorexia, dehydration, or fever | Oliveira and Ruegg (2014) |
| SCC | Bulk milk SCC (bmscc) | Bulk milk scc; mean, geometric mean or geometric weighted mean (weighted by individual cow milk yields) | |
| SCC | Elevated cow SCC ≥ 100,000 cells/mL | Elevated SCC defined to indicate (subclinical) mastitis | Deutsche Veterinärmedizinische Gesellschaft (DVG), 2012 |
| SCC | Elevated cow SCC ≥ 150,000 cells/mL | Elevated SCC defined to indicate (subclinical) mastitis in heifers | Santman‐Berends et al. (2012) |
| SCC | Elevated cow SCC ≥ 400,000 cells/mL | Proportion of cows ≥ 400,000 to indicate herd‐level subclinical infection | Welfare Quality® (2009) |
| SCC | SCC dynamics | e.g. from < 100,000 cells/ml to > 200,000 cells/ml; used to indicate new infections | Valde et al. (2005) |
| SCC | SCC group averages | Average SCC of cow level milk samples resulting from regular milk recording data, over time; quarterly, monthly, yearly | |
| SCC | Cell count transformations | log or similar transformations to Normalise or rescale SCC data (reduces impact of outliers) | Wiggans and Shook (1987) |
| Electrical conductivity (EC) |
Conductivity > 7.5 mS/cm or animal‐individual time‐series dependent detection |
Sensors for measuring EC on milk from each quarter, e.g. routinely implemented in automatic milking systems | Khatun et al. (2017), Norberg (2005) |