Table 2.

Effect of BA and EO, feed matrix, and day on PEDV detection as determined by qRT-PCR^*

	qRT-PCR Ct, dpi†
Item	0	1	3	7	14	21	42
Matrix × feed additive × day‡
FEED║
No feed additive	29.4	32.5	31.9	35.2	35.8	37.2	39.3(1/3)
EO	30.0	32.8	33.3	34.1	35.5	37.7	38.3
BA	29.7	31.7	33.5	33.4	35.6	38.0	40.4(1/3)
EO + BA	30.2	32.4	33.6	36.0	35.5	42.6(2/3)	45.0(3/3)
SDPP§
No feed additive	28.7	29.5	29.7	29.1	28.9	28.3	29.4
EO	28.4	29.3	29.3	29.1	28.2	30.3	29.4
BA	28.8	28.6	30.5	28.8	29.0	28.5	30.2
EO + BA	29.1	29.1	31.1	30.7	29.2	28.3	29.7
Matrix × day¶
FEED	29.8e,f	32.3d	33.1d	34.7c	35.6c	38.9b	40.7a
SDPP	28.8f	29.1e,f	30.2e	29.4e,f	28.8f	28.9f	29.7e,f
Day**	29.3e	30.7d	31.6c	32.1c	32.2c	33.9b	35.2a

^*An initial tissue culture (2.5 mL diluted virus inoculum, 10⁵ TCID₅₀/mL) was inoculated into 22.5 g of gestation diet (FEED) or SDPP treated with 0.02% EO product, 0.5% BA product, combination of EO and BA products (EO + BA) (DSM Nutritional products, Parsippany, NJ), or no chemical treatment.

^†Ct required to detect genetic material. A higher Ct value is indicative of less genetic material present.

^‡Matrix × treatment × day interaction, n = 3 for each value. SEM = 0.90, P = 0.094.

^║Swine gestation diet.

^§SDPP (APC Functional Proteins, Ankeny, IA).

^¶Matrix × day interaction, n = 12 for each value. SEM = 0.45, P < 0.001.

^**Main effect of day, n = 24 for each value. SEM = 0.32, P < 0.001.

^(X/X)Superscripts denote number of samples containing no detectable PEDV genetic material following 45 cycles. A value of 45.0 was assumed for samples with nondetectible RNA for analysis.

^a,b,c,d,e,fMeans within interaction or main effect lacking a common superscript differ (P < 0.05).