FIGURE 1.

Schematic overview of experimental design and gastrointestinal (GIT) tissue collection for proteome analyses. (A) Four hundred eggs were incubated under standard conditions in one single-stage egg incubator until embryonic day 18. (B) In ovo inoculations contained one of the following: 0.2 ml of 0.9% sterile saline (S), which served as the control group, or ∼10² cells of Citrobacter freundii (CF), Citrobacter spp. (C2), or a lactic acid bacteria mixture (L) was administered into the amnion. (C) After inoculation, up to 30 eggs were allocated by treatments into three separate benchtop hatchers per treatment. (D) Ten days posthatch, chicks were selected for ileum sample collection (pooled samples of two birds per treatment) to perform proteome analyses.