Table 2.

Effect of mannan oligosaccharide (Actigen; ACT)¹ and porcine reproductive and respiratory syndrome virus (PRRSV)² on pig performance after PRRSV infection

		Treatment4					P-value
Item	n3	CON	ACT	ICON	IACT	SEM	ACT	PRRSV	ACT × PRRSV
0 to 14 d after inoculation
ADG, g	8	674	693	258	288	33	0.491	<0.001	0.852
ADFI, g	8	1035	954	563	616	54	0.789	<0.001	0.217
G:F, g/kg	8	663	730	454	453	43	0.445	<0.001	0.433
d 14 to 28 after inoculation
ADG, g	8	713	709	495	477	30	0.650	<0.001	0.708
ADFI, g	8	1281	1317	957	828	75	0.550	<0.001	0.312
G:F, g/kg	8	567	549	529	583	31	0.547	0.950	0.259
d 28 to 42 after inoculation
ADG, g	8	950	925	661	756	44	0.450	0.002	0.216
ADFI, g	8	1963	1775	1855	1538	125	0.047	0.266	0.570
G:F, g/kg	8	486	526	357	508	26	0.003	0.052	0.042
d 0 to 42 after inoculation
ADG, g	8	779	776	479	509	24	0.588	<0.001	0.488
ADFI, g	8	1427	1349	1127	994	52	0.072	<0.001	0.602
G:F, g/kg	8	572	602	460	515	22	0.073	0.004	0.580

¹Pigs were fed ACT (Actigen, Alltech, Inc., Nicholasville, KY) diets for 8 wk starting at weaning; after 2 wk of 8-wk feeding, pigs were challenged with PRRSV.

²Pigs were challenged with PRRSV at 5 wk of age.

³A pig was an experimental unit; each treatment had 8 pigs except ICON (7 pigs, 1 pig euthanized at 18 d postinfection).

⁴CON: uninfected control-fed pigs; ACT: uninfected ACT-fed pigs; ICON: infected control-fed pigs; IACT: infected ACT-fed pigs.