Table 3 Prevalence and odds ratio for clinical mastitis in each stage of production
0–60 days | 61–120 days | 121–180 days | ≥181 days | ||||||
|---|---|---|---|---|---|---|---|---|---|
N | Mean | Odd ratio (95%CIa) | Mean | Odd ratio (95%CIa) | Mean | Odd ratio (95%CIa) | Mean | Odd ratio (95%CIa) | |
Parity | |||||||||
1 | 2025 | 7.3 | Reference | 2.9 | Reference | 2.8 | Reference | 4.0 | Reference |
2 | 2565 | 9.4 | 1.33 (1.07–1.65) | 6.5 | 2.46 (1.81–3.34) | 3.9 | 1.53 (1.09–2.14) | 7.6 | 1.97 (1.51–2.58) |
3 | 2163 | 12.2 | 1.72 (1.38–2.13) | 7.3 | 2.81 (2.06–3.84) | 5.1 | 2.01 (1.44–2.81) | 8.6 | 2.07 (1.57–2.72) |
4 | 1370 | 12.6 | 1.78 (1.40–2.26) | 5.4 | 2.05 (1.43–2.93) | 5.9 | 2.41 (1.68–3.45) | 8.0 | 1.87 (1.38–2.54) |
≥ 5 | 1540 | 14.3 | 2.12 (1.68–2.66) | 5.8 | 2.27 (1.61–3.21) | 4.3 | 1.73 (1.19–2.52) | 8.5 | 2.00 (1.48–2.70) |
Calving seasonc | |||||||||
Spring | 2179 | 8.7 | NSb | 5.8 | NSb | 5.5 | NSb | 6.7 | 0.70 (0.56–0.87) |
Summer | 2445 | 14.0 | 1.64 (1.37–1.97) | 5.8 | 3.2 | 0.66 (0.49–0.88) | 4.7 | 0.46 (0.37–0.59) | |
Autumn | 2619 | 11.1 | 1.26 (1.05–1.52) | 5.1 | 3.6 | 0.74 (0.56–0.97) | 8.0 | 0.81 (0.67–0.99) | |
Winter | 2420 | 9.2 | Reference | 6.0 | 4.9 | Reference | 9.6 | Reference | |