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.
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.
Krause
Denis O
DO
CSIRO Livestock Industries, Long Pocket Laboratories, Indooroopilly, Brisbane, Qld 4068, Australia1.
Bunch
Rowan J
RJ
CSIRO Livestock Industries, Long Pocket Laboratories, Indooroopilly, Brisbane, Qld 4068, Australia1.
Conlan
Lawrence L
LL
CSIRO Livestock Industries, Long Pocket Laboratories, Indooroopilly, Brisbane, Qld 4068, Australia1.
Kennedy
Peter M
PM
CSIRO Livestock Industries, Long Pocket Laboratories, Indooroopilly, Brisbane, Qld 4068, Australia1.
Smith
Wendy J
WJ
CSIRO Livestock Industries, Long Pocket Laboratories, Indooroopilly, Brisbane, Qld 4068, Australia1.
Mackie
Roderick I
RI
Department of Animal Sciences, University of Illinios, Urbana, IL, USA2.
McSweeney
Christopher S
CS
CSIRO Livestock Industries, Long Pocket Laboratories, Indooroopilly, Brisbane, Qld 4068, Australia1.
D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development*; D002482:Cellulose / Q000378:metabolism; D015169:Colony Count, Microbial; D004063:Digestion; D017753:Ecosystem; D006095:Gram-Positive Cocci / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D015345:Oligonucleotide Probes; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D012417:Rumen / Q000737:chemistry / Q000382:microbiology*; D012756:Sheep
D015345:Oligonucleotide Probes; D012336:RNA, Ribosomal, 16S; D002482:Cellulose