Rumen microbiome in dairy calves fed copper and grape-pomace dietary supplementations: Composition and predicted functional profile

PLoS One. 2018 Nov 29;13(11):e0205670. doi: 10.1371/journal.pone.0205670. eCollection 2018.

Abstract

The rumen microbiome is fundamental for the productivity and health of dairy cattle and diet is known to influence the rumen microbiota composition. In this study, grape-pomace, a natural source of polyphenols, and copper sulfate were provided as feed supplementation in 15 Holstein-Friesian calves, including 5 controls. After 75 days of supplementation, genomic DNA was extracted from the rumen liquor and prepared for 16S rRNA-gene sequencing to characterize the composition of the rumen microbiota. From this, the rumen metagenome was predicted to obtain the associated gene functions and metabolic pathways in a cost-effective manner. Results showed that feed supplementations did alter the rumen microbiome of calves. Copper and grape-pomace increased the diversity of the rumen microbiota: the Shannon's and Fisher's alpha indices were significantly different across groups (p-values 0.045 and 0.039), and Bray-Curtis distances could separate grape-pomace calves from the other two groups. Differentially abundant taxa were identified: in particular, an uncultured Bacteroidales UCG-001 genus and OTUs from genus Sarcina were the most differentially abundant in pomace-supplemented calves compared to controls (p-values 0.003 and 0.0002, respectively). Enriched taxonomies such as Ruminiclostridium and Eubacterium sp., whose functions are related to degradation of the grape- pomace constituents (e.g. flavonoids or xyloglucan) have been described (p-values 0.027/0.028 and 0.040/0.022 in Pomace vs Copper and Controls, respectively). The most abundant predicted metagenomic genes belonged to the arginine and proline metabolism and the two- component (sensor/responder) regulatory system, which were increased in the supplemented groups. Interestingly, the lipopolysaccharide biosynthetic pathway was decreased in the two supplemented groups, possibly as a result of antimicrobial effects. Methanogenic taxa also responded to the feed supplementation, and methane metabolism in the rumen was the second most different pathway (up-regulated by feed supplementations) between experimental groups.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Feed*
  • Animals
  • Cattle
  • Copper / administration & dosage*
  • Dietary Supplements*
  • Microbiota / drug effects*
  • Microbiota / genetics
  • RNA, Ribosomal, 16S / genetics
  • Rumen / drug effects
  • Rumen / microbiology
  • Vitis / chemistry

Substances

  • RNA, Ribosomal, 16S
  • Copper

Grants and funding

This work is part of the project VINCARN (“Miglioramento delle carni bovine, suine e avicole attraverso l’utilizzo di sottoprodotti della filiera enologica per fini mangimistici”) supported by a grant from the Rural Development Plan 2007 – 2013 – MISURA 1.2.4 - Regione Abruzzo – Italy DH26/40 (Project manager Prof. Giuseppe Martino). The authors are grateful to the company “Mario Maesa,” Casoli (CH), Italy, for the kind cooperation. The work of FB and G. Masetti was supported by the EU- FP7 project INDIGO, in the framework of People Marie Sklodowska-Curie Actions, Marie Curie Industry-Academia Partnerships and Pathways (grant agreement number: 612116).