Table 4.
Descriptive statistics for the production, fertility and disease data for 606 UK dairy herds in 2012.
| Continuous variables | Range | Mean | SD | Missing | Source |
|---|---|---|---|---|---|
| Production | |||||
| Yield (mean kg /cow/year) | 4000–10800 | 7438 | 1276 | 574 | Dairy |
| Estimated yield (mean kg /cow/year) | 1182–11686 | 6994 | 1682 | 131 | Dairy |
| Protein% | 2.86–3.80 | 3.24 | 0.13 | 12 | Dairy |
| Butterfat% | 3.43–5.08 | 4.13 | 0.23 | 12 | Dairy |
| Fertility | |||||
| Calving interval (days) | 330–570 | 411.13 | 23.15 | 264 | Questionnaire |
| Calving to conception interval (days) | 40–249 | 124.42 | 30.76 | 308 | Questionnaire |
| Services per conception | 1.00–5.00 | 2.38 | 0.63 | 317 | Questionnaire |
| Abortion rate per cow in 2012 | 0–0.18 | 0.024 | 0.02 | 342 | Questionnaire |
| Disease | |||||
| Somatic cell count (x103 cells/ml) | 55.0–297.0 | 165.50 | 41.52 | 12 | Dairy |
| Bactoscan (×103 bacteria/ml) | 8–132 | 26.97 | 11.30 | 12 | Dairy |
| Categorical variables | n | % | Missing | Questionnaire |
|---|---|---|---|---|
| Previous herd diagnosis of infectious bovine rhinotracheitis (IBR) | 59 | 17.3 | 265 | Questionnaire |
| Previous herd diagnosis of leptospirosis | 17 | 5 | 264 | Questionnaire |
| Previous herd diagnosis of bovine viral diarrhoea (BVD) | 38 | 11.1 | 265 | Questionnaire |
| Previous herd diagnosis of Salmonella dublin | 2 | 0.6 | 265 | Questionnaire |
| Previous herd diagnosis of Johne’s disease | 167 | 49 | 265 | Questionnaire |
| TB status: Herd currently under restriction due to a bovine TB case | 37 | 10.8 | 261 | Questionnaire |