Table 1.
Summary of farm demographics, herds characteristics and previous experience with paratuberculosis (PTB) for the 163 Swiss dairy farms participating in the study, classified as seropositive (n = 9) or seronegative (n = 154) for PTB based on serum ELISA results.
| Total | Seropositive farms | Seronegative farms | |
|---|---|---|---|
| Farm size (hectares) | |||
| Median | 37 | 45 | 35 |
| IQR1 | 25.0–50.0 | 30.0–75.0 | 25.0–50.0 |
| Range (minimum-maximum) | 11–160 | 25–85 | 11–160 |
| Herd size (all cows ≥2 years) | |||
| Median | 42 | 50 | 41 |
| IQR1 | 32–57 | 41–55 | 32–57 |
| Range | 16–138 | 36–138 | 16–133 |
| Average milk yield (liters/cow/year) | |||
| Median | 7,800 | 8,600 | 7,800 |
| IQR1 | 7,000–9,000 | 7,500–9,000 | 7,000–9,000 |
| Range | 5,000–17,000 | 5,500–17,000 | 5,000–15,000 |
| Total (%) | Seropositive farms (%) | Seronegative farms (%) | |
|---|---|---|---|
| Farm PTB-status | 163 (100) | 9 (5.5) | 154 (94.5) |
| Agricultural zone | |||
| Midland zone | 86 (52.7) | 4 (44.4) | 82 (53.2) |
| Hill zone | 25 (15.3) | 3 (33.3) | 22 (14.3) |
| Mountain zones2 | 52 (32.0) | 2 (22.2) | 50 (32.5) |
| Stall system | |||
| Free stall | 140 (85.9) | 8 (88.9) | 132 (85.7) |
| Tie-stall | 23 (14.1) | 1 (11.1) | 22 (14.3) |
| Production system | |||
| Conventional3 | 91 (55.8) | 6 (66.7) | 85 (55.2) |
| Label4 | 55 (33.7) | 3 (33.3) | 52 (33.8) |
| Organic5 | 17 (10.5) | 0 (0) | 17 (11.0) |
| Reproduction management | |||
| Breading bull on farm | 37 (22.7) | 1 (11.1) | 36 (23.4) |
| Artificial insemination only | 126 (77.3) | 8 (88.9) | 118 (76.6) |
| Main cattle breed | |||
| Holstein/Red Holstein | 78 (47.9) | 6 (66.7) | 72 (46.8) |
| Brown Swiss | 49 (30.0) | 1 (11.1) | 48 (31.2) |
| Swiss Fleckvieh | 15 (9.2) | 0 (0) | 15 (9.7) |
| Other breeds6 | 21 (12.9) | 2 (22.2) | 19 (12.3) |
| Seasonal calving7 | |||
| Yes | 11 (6.7) | 2 (22.2) | 9 (5.8) |
| No | 152 (93.3) | 7 (77.8) | 145 (94.2) |
| Previous PTB cases in the herd | |||
| Yes | 13 (8.0) | 5 (55.6) | 8 (5.2) |
| No | 122 (74.8) | 3 (33.3) | 119 (77.3) |
| Unknown | 28 (17.2) | 1 (11.1) | 27 (17.6) |
| Origin of the sick animals | |||
| Animal(s) raised on farm | 11 (84.6) | 4 (80.0) | 7 (87.5) |
| Purchased animal(s) | 2 (15.4) | 1 (20.0) | 1 (12.5) |
1Interquartile range: first quartile (25th percentile) – third quartile (75th percentile).
2Including all four mountain zones defined in the Swiss agricultural system: map.geo.admin.ch.
3As described in: Ökologischer Leistungsnachweis (admin.ch).
4As described in: www.ipsuisse.ch.
5As described in: www.biosuisse.ch.
6Including Jersey, Montbéliarde, Kiwi-Cross, Normande, Simmentaler and crossbreeds.
7Seasonal calving: systems focused on having most cows calve over a short period (about 12 weeks) starting in late winter so that the period of maximum feed demand coincides with the period of peak pasture growth rates around mid-spring.