Background
This study aimed to investigate differences in the structure and function of the rumen microbiome and its associated changes in rumen fermentation patterns and apparent nutrient digestibility in dairy cattle with different sorting behavior. Twenty-four Holstein cows in mid-lactation were initially enrolled in the experiment. All cows were fed and milked three times daily throughout the entire 28-day experimental period, comprising a 7-day pre-trial and a 21-day main trial. On days 1, 7, 14, and 21 of the main trial, feed sorting behavior was measured, and feed and feces samples were collected to determine apparent nutrient digestibility. Rumen content samples were collected on day 21 to measure pH, volatile fatty acids (VFA), and rumen microbiome structure and function. Based on feed sorting behavior, twelve cows were selected and divided into two groups: six cows that were severely sorted for fine particles-severely rejected long particles (SES; n = 6) and six cows that were slightly sorted for fine particles-slightly rejected long particles (SLS; n = 6).
Results
Comparative analysis revealed significant differences between the groups. The SES group exhibited lower rumen pH values and higher concentrations of total VFA (TVFA) and acetate (P |
