Table 1.

Isolation of PRRSV in serum and semen samples from PRRSV-inoculated and negative-control boars

Group (n)a	PRRSV type	Sample type	No. of positive boars at the indicated day postinfection
			−42	−21	−7	0	4	7	10	14	18	21	25	28	32	35	39	42	46	49	53	56	60
T01 (5)	European	Serum	0	0	0	0	5	5	5	5	4	3	4	4	2	2	2	2	0	0	0	0	0
	European	Semen	0	0	0	0	5	5	5	4	3	3	2	3	2	0	3	3	2	0	2	0	0
	Vaccine	Serum	0	2	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	Vaccine	Semen	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
T02 (5)	North American	Serum	0	0	0	0	5	5	5	4	2	0	0	0	0	0	0	0	0	0	0	0	0
	North American	Semen	0	0	0	0	5	5	5	3	0	0	0	0	0	0	0	0	0	0	0	0	0
	Vaccine	Serum	0	2	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	Vaccine	Semen	0	2	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
T03 (5)	European	Serum	0	0	0	0	5	5	5	5	4	4	3	2	3	2	2	2	0	0	0	0	0
	European	Semen	0	0	0	0	5	5	5	4	3	2	4	0	3	0	2	0	3	0	3	0	0
T04 (5)	North American	Serum	0	0	0	0	5	5	5	5	5	4	3	2	4	0	2	0	0	0	0	0	0
	North American	Semen	0	0	0	0	5	5	5	3	3	3	3	0	4	2	4	3	0	2	3	0	0
T05 (5)	Vaccine	Serum	0	3	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	Vaccine	Semen	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

^an, number of boars in group.