PSIX-3 Rumen Bacteria Composition between pre-Weaning and Post-Weaning Dairy Calves

Abstract The purpose of this experiment was to study the changes fecal bcteria calves before and after weaning. Among 365 Holstein born in 2021, 8 with similar body weight were selected weaning (60 ± 2 d) (120 6 d), rectal manure collected. Fecal samples for volatile fatty acids microorganisms. results showed that: 1) Sobs index, Ace Chao1 Simpson index Shannon pre-weaning post-weaning significantly different (P < 0.05); 2) At phylum level, both characterized by Bacteroidetes, Firmicutes, Actinomyces, is dominant bacteria. Compared calves, composition bacteria at relative abundance Patescibacteria Campilobacterota, decreased 3) family predominant are Lachnospiraceae, Vibriospira, Prevotella. microbiota abundances Oscillospiraceae, Muribaculaceae, Rikenellaceae, Erysipelotrichaceae, Christensenellaceae, Anaerovoracaceae, Clostridiaceae, norank_o__RF39, Monoglobaceae UCG-010 increased 0.05), while Lactobacillaceae, Bacteroidaceae, Ruminococcaceae, Butyricicoccaceae Coriobacteriaceae reduced 4) genus compared UCG-005, norank_f__Muribaculaceae, unclassified_f__Lachnospiraceae, Rikenellaceae_RC9_gut_group, Prevotellaceae_UCG-003, Paeniclostridium, Christensenellaceae_R-7_group, Coprococcus, Clostridium_sensu_stricto_1, Agathobacter, norank_f__norank_o__RF39 Lactobacillus, Bacteroides, Blautia, Faecalibacterium 0.05). In conclusion, experiment, there significant differences Tibet. This provides reference information feeding management high altitude areas.