Table 1.
Environmental parameters investigated in 20 Swedish pig herds with (case herds) and without (control herds) a history of Streptococcus suis-infections in grower pigs
| Environmental parameters | Control herds (n = 9)a | Case herds (n = 10) | P valueb | ||
|---|---|---|---|---|---|
| Mean | SD | Mean | SD | ||
| Temperature (°C) | 20.4 | 3.42 | 19.5 | 3.95 | 0.59 |
| Carbon dioxide (ppm) | 1622 | 950 | 1550 | 695 | 0.85 |
| Ammonia in pens, mean (ppm) | 6.6 | 3.3 | 6.6 | 2.6 | 0.63 |
| Air relative humidity (%) | 55.9 | 17.5 | 58.4 | 12.4 | 0.73 |
| Air velocity (solid floor or deep straw bedding), mean (m/s) | 0.10 | 0.05 | 0.09 | 0.03 | 0.34 |
| Air velocity (slatted floor), mean (m/s)c | 0.14 | 0.08 | 0.07 | 0.03 | 0.10 |
aBiosecurity rules in one herd prohibited measuring equipment being brought in
bP values were calculated using Welch’s t-test. P < 0.05 was considered significant
cHerds using deep straw bedding not included, leaving control herds n = 6 and case herds n = 9