Table 4 Estimated sensitivity (Se) and specificity (Sp) for the digital refractometer at different cut-offs in Brix, 95% confidence intervals are given in brackets in 167 colostrum samples from 19 dairy herds in a specific region in Norway (Ringsaker municipality, Hedmark County)
Brix 18% | Brix 19% | Brix 20% | Brix 21% | Brix 22% | Brix 23% | Brix 24% | |
|---|---|---|---|---|---|---|---|
Se | 100.0 (92.7–100) | 95.9 (86.0–99.5) | 91.8 (80.4–97.7) | 77.6 (63.4–88.2) | 69.4 (54.6–81.7) | 55.1 (40.2–69.3) | 44.9 (30.7–59.8) |
Sp | 44.9 (35.7–54.3) | 58.5 (49.0–67.5) | 67.8 (58.6–76.1) | 78.8 (70.3–85.8) | 83.1 (75.0–89.3) | 91.5 (85.0–95.9) | 95.8 (90.4–98.6) |