College of Animal Science and Technology Northwest A&F University Yangling 712100 China;
College of Animal Science and Technology Northwest A&F University Yangling 712100 China;
College of Animal Science and Technology Northwest A&F University Yangling 712100 China;
College of Animal Science and Technology Northwest A&F University Yangling 712100 China;
16S rRNA; Caecal microbiota; Laying hen; Developmental stage; Intestinal health;