Table 3.
Health and production effects of BVDV under different production settings in Europe (observational studies) (reproduced from Table 5 of the EU Thematic network on control of bovine viral diarrhoea virus (BVDV) (2001))
| Country/region | Outcome variable | BVD condition (risk or exposure factor) | Measure | Number of animals/herd | Size of measure | Reference |
|---|---|---|---|---|---|---|
| Netherlands | Reduced milk yield with ˃ 10% | Seroconversion vs no seroconversion | OR |
22 seroconverted 32 not seroconverted |
11.5 (CI 3.0–43.5) for more than 10% reduction in milk yield | Moerman et al. (1994) |
| Netherlands | Moderate or severe bronchopneumonia | Receiving colostrum from AB negative dams (A) vs. AB positive dams (B) | Incidence risk |
AB‐neg colostrum: 44 calves AB‐pos colostrum: 86 calves |
A: 68.2% developed symptoms B: 40.7% developed symptoms |
Moerman et al. (1994) |
| Sweden | Heart girth | PI calves vs. non‐PI calves |
Cm at 80 days Cm at 180 days |
8 PI 13 non‐PI |
80 days: PI: 96.3 ±4.7 cm; non‐PI: 100.5 ±2.3 cm PI: 123.3 ±8.8 cm; non‐PI: 130.2 ± 2.0 cm |
Larsson et al. (1994) |
| Sweden | Mastitis | Recent herd infection compared to low level of A in bulk ilk | OR | 91 herds (7 with recent inf. And 84 without inf.) | 1.8 (CI: 1.7–2.8) | Niskanen et al. (1995) |
| Sweden | Miscellaneous diseases | Recent herd infection compared to low level of A in bulk ilk | OR | 91 herds (7 with recent inf. And 84 without inf.) | 2.8 (CI: 1.7–4.4) | Niskanen et al. (1995) |
| Sweden | Retained placenta | Recent herd infection compared to low level of A in bulk ilk | OR | 91 herds (7 with recent inf. And 84 without inf.) | 2.8 (CI: 1.6–4.7) | Niskanen et al. (1995) |
| Sweden | Oestrus stimulating treatment | Long‐term herd infection compared to low level of AB in bulk milk | OR | 142 herds (58 with inf. and 84 without) | 1.8 (CI: 1.3–2.6) | Niskanen et al. (1995) |
| Sweden | Calving interval | Long‐term herd infection compared to low level of AB in bulk milk | Days | 142 herds (58 with inf. and 84 without) |
Long‐term inf.: 394 (389–398) Non‐infected: 385 (381–389) |
Niskanen et al. (1995) |
| Sweden | Average annual milk yield per cow | Herds with detection of virus vs free herds | kg ECM |
319 case herds 2,270 control herds |
Interaction with herd size: 30 cows: −142 kg (CI: −281 to −3) less in case herds 40 cows: −198 kg (CI: −330 to −66) 50 cows: −254 kg (−389 to −119) |
Lindberg and Emanuelson (1997) |
| Sweden | Average bulk milk somatic cell count × 1,000 | Herds with detection of virus vs free herds | cells/mL |
319 case herds 2,270 control herds |
10,300 (1,600–18,900) cells/mL more in case herds | Lindberg and Emanuelson (1997) |
| Norway | Clinical mastitis | Herds with rise in bulk milk antibodies vs herds with continuous low level | Incidence rate | 300 exposed herds vs 13,671 non‐exposed | 7.1% (CI: 0.2–11.4) increase in exposed herds | Waage (2000) |
| Switzerland | Fetal death (mid‐term abortion) | Seroconversion vs no seroconversion | OR and PAF |
62 cases 952 controls |
3.10 (CI: 1.16–8.29), PAF 7% (CI: 2.4–14) | Rüfenacht et al. (2001) |
| France | Late return to service (after 25 days) | Past‐infected‐recently recovered vs Not recently infected | RR |
150,854 AI 122,697 cows 6,149 herds |
1.03 (CI: 1.01–1.05) | Robert et al. (2004) |
| France | Late return to service (after 25 days) | Past steadily infected vs. Not recently infected | RR |
150,854 AI 122,697 cows 6,149 herds |
1.11 (CI: 1.05–1.17) | Robert et al. (2004) |
| France | Late return to service (after 25 days) | Recently infected vs Not recently infected | RR |
150,854 AI 122,697 cows 6,149 herds |
1.11 (CI: 1.02–1.22) | Robert et al. (2004) |
| Holland | Prevalence of animals with clinical signs | Transient infection | % | 136 cattle (1 herd) | 7 of all animals with transient infection showed clinical signs (5%) | Moerman et al. (1994) |