Table 3.

Effect of eggshell temperature (EST) during mid-incubation¹ and post-hatch feeding strategy² on incidence and severity of colibacillosis lesions³ in broilers during colibacillosis⁴.

Treatment	n5	No lesions6 (%)	tMLS7 (score)
EST
Control	18	38 ± 2.6	3.0 ± 0.25
Higher	18	37 ± 2.5	2.9 ± 0.23
Feeding strategy
Delayed	18	37 ± 2.5	2.9 ± 0.24
Early	18	39 ± 2.6	2.9 ± 0.24
EST × Feeding strategy
Control × Delayed	9	34 ± 3.6	3.4 ± 0.37a
Control × Early	9	41 ± 3.7	2.6 ± 0.32b
Higher × Delayed	9	39 ± 3.5	2.5 ± 0.29b
Higher × Early	9	36 ± 3.6	3.2 ± 0.34a
P-values
EST		0.26	0.90
Feeding strategy		0.09	0.77
EST × Feeding strategy		0.67	<0.01

Note: Data are presented as mean ± SE.

¹EST during mid-incubation (embryo days 7–14) was either 37.8°C (Control) or 38.9°C (Higher), and the remaining incubation period EST was 37.8°C for both treatment groups.

²Feeding strategy was either direct access to feed and water after hatch (Early) or 48 h after hatch (Delayed).

³Sum of lesion scores from left air sac, right air sac, pericardium, and liver, each scored 0 (clean), 0.5 (single spot), 1 (two or more spots), 2 (patches), or 3 (extensive fibrination).

⁴Colibacillosis was induced by intratracheal E. coli (O78:K80 strain 506) inoculation at d 8 of age (dose 0.3 mL of 1.53 × 10⁷ CFU/mL).

⁵Pens, with 20 broilers dissected / pen, divided over 6 moments post inoculation (3 and 12 h, 1-2-4-7 days).

⁶Colibacillosis lesions³ = 0.

⁷tMLS = total Mean Lesion Score from broilers with colibacillosis lesions³ > 0.

^a-bMeans within a column and factor lacking a common superscript differ (P < 0.05).