Rumen microbial cluster identification and its influence on rumen metabolites and growth performance of young goats

The microbial clusters in the intestine (enterotypes) have been found to relate to host metabolism and health. It is the first time that ruminal bacterial clustering in young goats is studied in the present experiment. The ruminal microbiome in 99 6 mo-old goats was analyzed and identified to 2 enterotypes: cluster 1 (n = 38) was dominated by genus Prevotella (P-cluster), and cluster 2 (n = 61) was dominated by Ruminococcus (R-cluster). Compared with P-cluster goats, R-cluster goats had greater growth rates, the concentrations of propionate, butyrate, and 18 free amino acids¸ and the proportion of unsaturated fatty acids, but lower acetate molar percentage, the acetate to propionate ratio and several odd and branched chain and saturated fatty acids in rumen fluid. The ruminal microbiome composition differed significantly between 2 enterotypes. At the genus level, several members of Firmicutes, including Ruminococcus, OscillospiraceaeNK4A214 group and Christensenellaceae R-7 group were significantly higher in R-cluster, whereas Prevotellaceae members, such as Prevotella and Prevotellaceae UCG-003, were significantly higher in P-cluster. Spearman correlation analysis showed that those R-cluster-enriched bacteria have negative correlations significantly with those P-cluster-enriched bacteria. Moreover, we found the concentrations of propionate, butyrate and free amino acids, and the proportion of unsaturated fatty acids were positively correlated with those R-cluster-enriched bacteria. The concentrations of acetate, acetate to propionate ratio and the proportion of saturated fatty acids and odd and branched chain fatty acids were positively correlated with those P-cluster-enriched bacteria.

Key Words: rumen, microbial cluster, metabolites, growth performance, goats.

Published in the proceedings of the 10th Symposium on Gut Health in Production of Food Animals 2022, St. Louis, USA.