Streptococcus suis in Swedish grower pigs: occurrence, serotypes, and antimicrobial susceptibility

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 value^b
Environmental parameters	Mean	SD	Mean	SD	P value^b
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

ISSN: 1751-0147