Table I.

Prevalence of Mycoplasma hyopneumoniae colonization at weaning (initial prevalence)

Group	Sow herd (source)	Prevalence at weaning (%)
1	A	51.28
2	A	28.2
3	A	48.7
4	A	30.76
5	A	17.94
6	A	5.12
7	A	15.38
8	A	17.94
9	A	15.78
10	B	28.2
11	B	38.46
12	B	7.69
13	B	2.56
14	B	0
15	B	7.69
16	B	5.12
17	C	5.12
18	C	2.5
19	C	5.12
20	C	2.56