Repeated ruminal dosing of Ruminococcus spp. does not result in persistence, but changes in other microbial populations occur that can be measured with quantitative 16S-rRNA-based probes

• Published in: Microbiology (Society for General Microbiology) Vol. 147; no. 7; pp. 1719 - 1729
• Main Authors: Krause, Denis O, Bunch, Rowan J, Conlan, Lawrence L, Kennedy, Peter M, Smith, Wendy J, Mackie, Roderick I, McSweeney, Christopher S
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01-07-2001; Society for General Microbiology
• Subjects: Animal, plant and microbial ecology; Animals; Bacteria - classification; Bacteria - genetics; Bacteria - growth & development; Biological and medical sciences; Cellulose; Cellulose - metabolism; Colony Count, Microbial; Digestion; Ecosystem; Fibrobacter succinogenes; Fundamental and applied biological sciences. Psychology; Gram-Positive Cocci - genetics; Gram-Positive Cocci - growth & development; Gram-Positive Cocci - metabolism; Microbial ecology; Normal microflora of man and animals. Rumen; Oligonucleotide Probes; RNA, Ribosomal, 16S - genetics; rRNA 16S; Rumen - chemistry; Rumen - microbiology; Ruminococcus; Sheep; Fibrobacter succinogenes; Stomach; Eubacteriales; Microorganism interrelationships; Animal microorganism relation; Digestive system; Ribosomal DNA; Microflora; Rumen; Peptococcaceae; Fibrolytic bacteria; Bacteroidaceae; Vertebrata; Mammalia; 16S-RNA; Ruminococcus; Bacteria; Sheep; Population dynamics; Artiodactyla; Ungulata
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-147-7-1719

CSIRO Livestock Industries, Long Pocket Laboratories, Indooroopilly, Brisbane, Qld 4068, Australia 1
Department of Animal Sciences, University of Illinios, Urbana, IL, USA 2
Author for correspondence: Denis O. Krause. Tel: [phone]. Fax: [phone]. e-mail: denis.krause{at}li.csiro.au
Digestibility of fibre in ruminants may be improved by the introduction of highly fibrolytic strains of ruminal bacteria. This approach may be feasible if, for example, strains of Ruminococcus that are significantly more fibrolytic than the normal population of Ruminococcus are used for inoculation purposes. Introduced strains of bacteria, irrespective of ecosystem, often decline after inoculation, and in this study, highly fibrolytic strains of Ruminococcus were continuously dosed to ensure that measurements of fibre digestion were made in the presence of significant numbers of the introduced bacteria. During dosing the total culturable count increased significantly ( P <0·05), but declined post-dosing. The level of dosed Ruminococcus , and total Ruminococcus , Fibrobacter succinogenes and eukaryotes measured by 16S rRNA probes increased significantly ( P <0·05) during the dosing period, but also declined post-dosing. When in vitro nylon bag digestibility, feed intake or whole-tract digestibility was measured, no improvement could be measured.
Keywords: Fibrobacter succinogenes , eukaryotes, ecology, fibre, cellulose digestibility Abbreviations: BCVFA, branched-chain volatile fatty acids; DDMI, digestible dry matter intake; DMD, dry matter digestibility; DMI, dry matter intake; TCC, total culturable count