책임운영기관 농촌진흥청 국립축산과학원 (로고)

Diversity of bacteria and their function in cattle gastrointestinal tracts can influence animal wel-fare. Next-generation sequencing (NGS) was used to investigate microbial diversity in fecal of Hanwoo steers reared under natural grazing (GS) and housing (HS) systems. Additionally, se-rum metabolic parameters, such as liver and kidney markers, mineral and lipid content changes, and their correlation with pyrotags, were studied. A total 6468 +- 87.86 operational taxonamic unites (OTUs) were identified in both steer groups, of which 3538 +- 38.17 OTUs were from graz-ing steer and 2930 +- 94.06 OTUs were from GS. Chao1 index analysis revealed a higher bacterial richnes in GS . The dominant bacterial taxa were Bacteroidetes and Firmicutes. GS showed lower Bacteroidetes and higher Firmicutes abundance than HS. The serum of HS showed consistent in-creases in gamma-glutamyl transpeptidase (γGTP), glucose (GLU), total cholesterol (T-CHO) and triglyceride (TG) levels. The impact of GS on animal health and serum metabolic markers was strongly correlated with microbiota. As shown in this study, grazing has a significant impact on the fecal microbiota at the phylum and family levels, as well as the serum biochemical metabo-lites of Hanwoo steers.