From: Impact of foot-and-mouth disease on mastitis and culling on a large-scale dairy farm in Kenya
Variable | Total population | Culling | |||
---|---|---|---|---|---|
N | (col %) | Rate per 1000 cattle-months (95% CI) | HR (95% CI) | P -value | |
FMD | |||||
Yes | 400 | 62.1 | 14.4 (11.2, 18.6) | 2.2 (1.3, 3.7) | 0.005 |
No | 244 | 37.9 | 6.6 (4.1, 10.6) | ||
Age (quintiles) a | |||||
−28- <227d | 128 | 19.9 | 5.0 (2.4, 10.5) | 1.6b (1.3, 1.9) | <0.0001 |
227- < 577d | 129 | 20.0 | 2.0 (0.66, 6.3) | ||
577- < 974d | 129 | 20.0 | 12.6 (7.8, 20.3) | ||
974- < 1363d | 129 | 20.0 | 17.1 (11.2, 25.9) | ||
1364-3543d | 129 | 20.0 | 23.2 (15.9, 33.8) | ||
Parity | |||||
0 | 381 | 59.2 | 4.8 (3.1, 7.4) | 1.5b (1.3, 1.8) | <0.0001 |
1 | 138 | 21.4 | 27.1 (19.5, 37.8) | ||
2 | 77 | 12.0 | 11.6 (6.1, 22.4) | ||
3 | 29 | 4.5 | 36.8 (19.2, 70.7) | ||
≥4 | 19 | 3.0 | 18.2 (5.9, 56.6) | ||
Days in milk | |||||
Pre-lactating | 373 | 57.9 | 4.9 (3.1, 7.6) | 1.7b (1.5, 1.9) | <0.0001 |
Early-lactation (<0-100d) | 107 | 16.6 | 15.2 (9.3, 24.9) | ||
Mid-lactation (101-250d) | 85 | 13.2 | 18.8 (11.3, 31.2) | ||
Late-lactation (>250d) | 44 | 6.8 | 25.4 (13.7, 47.2) | ||
Dry | 35 | 5.4 | 46.0 (27.7, 76.3) | ||
Breed | |||||
100% Exotic breed | 551 | 85.6 | 11.5 (9.0, 14.6) | 0.7b (0.6, 1.3) | 0.52 |
<25% Indigenous | 53 | 8.2 | 14.6 (7.3, 29.2) | ||
25% Indigenous | 28 | 4.4 | 3.7 (0.5, 26.0) | ||
50% indigenous | 12 | 1.9 | 8.8 (1.2, 62.7) |