Fecal microbiota of lambs fed purple prairie clover (Dalea purpurea Vent.) and alfalfa (Medicago sativa)

Citation

Huang, Q., Holman, D.B., Alexander, T., Hu, T., Jin, L., Xu, Z., McAllister, T.A., Acharya, S., Zhao, G., Wang, Y. (2018). Fecal microbiota of lambs fed purple prairie clover (Dalea purpurea Vent.) and alfalfa (Medicago sativa). Archives of Microbiology, [online] 200(1), 137-145. http://dx.doi.org/10.1007/s00203-017-1427-5

Plain language summary

Effects of condensed tannins (CT) on rumen microbes have been well studied but this is little information on the effects of CT on the hindgut microbiome of ruminants. The study assessed the effect of purple prairie clover (PPC) and PPC CT on the fecal microbiota of lambs using high-throughput 16S rRNA gene pyrosequencing. Results showed that bacterial community in sheep was dominated by Firmicutes and Bacteroidetes with many sequences unclassified at the genus level. Forage type and CT had no effect on the fecal microbial composition at the phylum level. Compared to the alfalfa diet, the mixture diet reduced the relative abundance of Akkermansia and Asteroleplasma. These results indicate that PPC CT up to 36 g/kg DM in the diet had no major effect on fecal microbial flora at the phyla level and exerted only minor effects on the genera composition of fecal microbiota in lambs.

Abstract

The present study assessed the effect of purple prairie clover (PPC) and PPC condensed tannins (CT) on the fecal microbiota of lambs using high-throughput 16S rRNA gene pyrosequencing. A total of 18 individual lambs were randomly divided into three groups and fed either green chop alfalfa (Alf), a 40:60 (DM basis; Mix) mixture of Alf and PPC, or Mix supplemented with polyethylene glycol (Mix-P) for 18 days. Fecal samples were collected on days 13 through 18 using digital rectal retrieval. The DNA of fecal samples was extracted and the microbial 16S rRNA gene amplicons were sequenced using 454 pyrosequencing. Regardless of diet, the bacterial community was dominated by Firmicutes and Bacteroidetes with many sequences unclassified at the genus level. Forage type and CT had no effect on the fecal microbial composition at the phylum level or on α-diversity. Compared to the Alf diet, the Mix diet reduced the relative abundance of Akkermansia (P = 0.03) and Asteroleplasma (P = 0.05). Fecal microbial populations in Alf and Mix-P clustered separately from each other when assessed using unweighted UniFrac (P < 0.05). These results indicate that PPC CT up to 36 g/kg DM in the diet had no major effect on fecal microbial flora at the phyla level and exerted only minor effects on the genera composition of fecal microbiota in lambs.