Different Lactobacillus species dominated in the crop microbiota of young chickens of one-week-old chickens in commercial production. Under clean conditions of experimental facilities in academic institution, E. coli may remain the most abundant bacterium in the crop of one-week-old chicks allowing even Clostridium perfringens to multiply. Common crop colonisers include also Enterococcus, Ruminococcus torque and Veillonella magna. With increasing age, additional bacterial species, e.g. Ornithobacterium or Gallibacterium may appear in the crop. Brachybacterium, Brevibacterium, Dietzia, Facklamia or Yaniella, all species characteristic for litter microbiota, can be detected as minority but common species in the crop indicating their “entry” into chickens without dissemination in distal parts of the intestinal tract.
