. 2020 Sep 1;99(11):5452–5460. doi: 10.1016/j.psj.2020.08.039

Table 1.

Summary of the layout of experiments 1 and 2.

Analysis type³	Experiment 1 ¹						Experiment 2 ²
	Production cycle 1		Production cycle 2		Production cycle 3		Cycle 1
	Farm 1	Farm 2	Farm 1	Farm 2	Farm 1	Farm 2	Farm 3
E. coli isolation and enumeration	At 3 and 6 wk⁴	At 3 and 6 wk	At 3 and 6 wk	At 3 and 6 wk	At 3 and 6 wk	At 3 and 6 wk	At 6 wk
E. coli susceptibility evaluation	At 3 and 6 wk	At 3 and 6 wk	At 3 and 6 wk	At 3 and 6 wk	At 3 and 6 wk	At 3 and 6 wk	At 6 wk
Production parameters	Average⁵	ND⁶	Average	ND	Average	ND	ND
Days of antimicrobial usage	Number of days	Number of days	Number of days	Number of days	Number of days	Number of days	ND
Serology	ND	ND	ND	ND	At 6 wk	At 3 and 6 wk	ND

In each experiment, the same samples were collected from both chicken houses (K1—E. coli vaccinated and K2—control, not vaccinated) at farms F1, F2, and F3.

Abbreviation: E. coli, Escherichia coli.

In experiment 1 birds were vaccinated against E. coli (K1) on the first day of life. In vaccinated birds, antimicrobial usage was prohibited for 14 d after E. coli vaccination. Control birds (K2) received antibiotics from day 1 of their life. In other stages of the production cycles, the antibiotic usage was the same in both groups.

In experiment 2 both the control and E. coli–vaccinated birds receive the same antimicrobials during the entire production cycle. Both groups received Linco-Spectin for the first 4 d of life. Birds in K1 were vaccinated against E. coli on the ninth day of life. Further antimicrobial usage was prohibited in both groups until the 23rd day of life (14 d after E. coli vaccination in K1).

What types of laboratory analyses were performed at different stages of experiments 1 and 2.

⁴

Samples were collected at the third and/or sixth week of birds' life.

⁵

Data were analyzed as an average value of each production parameter for each chicken house.

⁶

Not done.