Table 1. The inoculation method of different groups.

Group	Serial number	Sex	Weight (kg)	Inoculation method
PRRSV-HPS	1	Male	21.9	PRRSV BJ12: IM and IN at a dose of 6.7 × 103.675 TCID50/kg
	2	Female	15.8	HPS4: IN at a dose of 2 × 109 CFU/kg
	3	Female	18.1
	4	Male	7.1
PRRSV	1	Female	10.5	PRRSV BJ12: IM and IN at a dose of 6.7 × 103.675 TCID50/kg
	2	Male	18.4
	3	Male	15.6
HPS	1	Female	12.5	HPS4: IN at a dose of 2 × 109 CFU/kg
	2	Male	15.9
	3	Female	13.7
Control	1	Male	18.6	Inoculated with the same amount of RPMI-1640
	2	Female	11.9
	3	Male	13.1

PRRSV BJ12: 10^5.675 TCID₅₀/mL; HPS4: 1.66 × 10⁹ CFU/mL. RPMI-1640: Gibco, USA.

IM, intramuscular inoculation; IN, intranasal inoculation; PRRSV, porcine reproductive and respiratory syndrome virus; HPS, Haemophilus parasuis.