Differential effects of monensin and a blend of essential oils on rumen microbiota composition of transition dairy cows
| Autor: | Gerhard Breves, Melanie Schären, Tim Urich, S. Riede, Jürgen Hummel, Caroline Drong, K. Kiri, Mark R. Gardener, Ulrich Meyer, Sven Dänicke |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Rumen animal structures Firmicutes Gram-positive bacteria Population Biology Microbiology 03 medical and health sciences chemistry.chemical_compound RNA Ribosomal 16S Oils Volatile Genetics Animals Food science Monensin education 2. Zero hunger chemistry.chemical_classification education.field_of_study Microbiota Lachnospiraceae biology.organism_classification Diet 030104 developmental biology chemistry Fermentation Propionate Cattle Female Animal Science and Zoology Food Science Ruminococcaceae |
| Zdroj: | Journal of Dairy Science. 100:2765-2783 |
| ISSN: | 0022-0302 |
| Popis: | In response to oral application, monensin alters the rumen microbiota, increasing ruminal propionate production and energy availability in the animal. Data from different studies indicate that the susceptibility of rumen bacteria to monensin is mainly cell-wall dependent but tracing its activity to specific microbial groups has been challenging. Several studies have shown a similar effect for essential oils but results are inconsistent. To investigate the influence of monensin and a blend of essential oils (BEO, containing thymol, guaiacol, eugenol, vanillin, salicylaldehyde, and limonene) on the rumen microbiome, rumen liquid samples were collected orally on d 56 postpartum from cows that had either received a monensin controlled-release capsule 3 wk antepartum, a diet containing a BEO from 3 wk antepartum onward, or a control diet (n = 12). The samples were analyzed for pH, volatile fatty acid, ammonia, and lipopolysaccharide concentrations and protozoal counts. A 16S rRNA gene fingerprinting analysis (PCR-single-strand conformation polymorphism) and sequencing revealed that the BEO treatment had no effect on the rumen microbiota, whereas monensin decreased bacterial diversity. Twenty-three bacterial species-level operational taxonomic units were identified for which monensin caused a significant decrease in their relative abundance, all belonging to the phyla Bacteroidetes (uncultured BS11 gut group and BS9 gut group) and Firmicutes (Lachnospiraceae, Ruminococcaceae, and Erysipelotrichaceae). Ten bacterial operational taxonomic units belonging to the phyla Actinobacteria (Coriobacteriaceae), Bacteroidetes (Prevotella), Cyanobacteria (SHA-109), and Firmicutes (Lachnospiraceae and Ruminococcaceae) increased in relative abundance due to the monensin treatment. These results confirm the hypothesis that varying effects depending on cell-wall constitution and thickness might apply for monensin sensitivity rather than a clear-cut difference between gram-negative and gram-positive bacteria. No effect of monensin on the archaea population was observed, confirming the assumption that reported inhibition of methanogenesis is most likely caused through a decrease in substrate availability, rather than by a direct effect on the methanogens. The data support the hypothesis that the observed increase in ruminal molar propionate proportions due to monensin may be caused by a decrease in abundance of non-producers and moderate producers of propionate and an increase in abundance of succinate and propionate producers. |
| Databáze: | OpenAIRE |
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