Table 3.

Effects of dietary coated essential oil and organic mixture supplementation on growth performance of broiler chickens infected with Escherichia coli O78.

Item	Experimental design					Main effect				P-value1
	A	K	B	L	SEM	0	500 mg/kg	Non-challenge	Challenged	EOA	Challenged	Interaction effects
Day 1 to 21
ADG, g/d	41.4	42.4	40.8	42.7	0.36	41.9	41.8	41.1	42.6	0.811	0.074	0.575
ADFI, g/d	59.5	60.0	59.3	60.7	0.43	59.8	60.0	59.4	60.4	0.792	0.337	0.672
FCR, g/g	1.44	1.41	1.45	1.42	0.01	1.43	1.44	1.44a	1.42b	0.294	0.046	0.677
Day 22 to 42
ADG, g/d	90.7	80.5	89.7	80.5	1.79	85.6	85.1	90.2	80.5	0.927	0.035	0.235
ADFI, g/d	147.4a	144.8ab	127.8b	136.8ab	3.10	146.1	132.3	137.6	140.8	0.027	0.582	0.036
FCR, g/g	1.66ab	1.81a	1.44c	1.71ab	0.06	1.73	1.58	1.55	1.76	0.193	0.098	<0.001
Day 1 to 42
ADG, g/d	66.1	61.5	65.2	61.6	1.17	63.8	63.4	65.6	61.5	0.896	0.129	0.263
ADFI, g/d	103.4a	102.4ab	93.6b	98.8ab	1.56	102.9	96.2	98.5	100.6	0.031	0.476	0.034
FCR, g/g	1.58b	1.67a	1.44c	1.61a	0.04	1.63	1.52	1.51	1.64	0.216	0.129	<0.001

A = neither infection nor coated essential oil and organic acid mixture addition negative control; K = E. coli infection positive control; B = coated essential oil and organic acid mixture addition at 500 mg/kg but without infection; L = both essential oil and organic acid mixture addition at 500 mg/kg and E. coli O78 infection; SEM = standard error of the mean; ADG = average daily weight gain; ADFI = average daily feed intake; FCR = feed-to-gain ratio.

^{a, b, c} Means within the same row without a common superscript differ significantly (P < 0.05).

¹P-values represent the main effect of the diet, the main effect of E. coli O78 challenge, and the interaction between the dietary treatments and E. coli O78 challenge.