Probiotic and dietary manipulation of the gastrointestinal tract microbiota in beef cattle: towards improved performance under different dietary management in Canadian Prairies
Bibliographic record
Abstract
Microbial symbionts inhabiting the digestive tract of ruminants contribute to a wide range of metabolic functions essential for the survival of host. However, abrupt changes in the composition of diet can adversely affect the composition of these microbial communities, leading to metabolic disorders that could compromise the performance of the animals. Development of frothy bloat following exposure of over-wintered steers to legume pastures and impairment of ruminal fermentation as a result of feeding high-grain diets are common metabolic disorders affecting beef cattle in Canadian Prairies. Mitigation strategies to control these metabolic conditions are mainly based on dietary interventions, providing moderate protection to cattle. Understanding the contribution of microbiota to development of these metabolic conditions would pave the way towards implementing more effective strategies. In the first experiment of this thesis, the effects of supplementing the probiotic strain Propionibacterium acidipropionici P169 on the microbiota and metabolic profile of feedlot cattle receiving a high-grain diet were evaluated. Overall, the data suggest that P169 confers its beneficial effect via favoring the growth of cellulolytic bacteria, thus inhibiting the overgrowth of amylolytic bacteria and subsequent drop in the ruminal pH. In the second experiment, dynamics of rumen microbiota during development of frothy bloat and following administration of mitigating strategies was characterized (i.e., use of mixed alfalfa and sainfoin pasture and supplementing drinking water with Alfasure™). The data suggest that rapid proliferation of amylolytic bacteria following consumption of alfalfa contribute to development of frothy bloat. Dietary interventions used in this study prevented the development of clinal bloat, increased the proportions of cellulolytic bacteria, and alleviated bloat-associated dysbiosis in the composition of rumen microbiota. Finally, the third study evaluated the interrelationships of anaerobic rumen fungi (ARF) and ruminal bacteria in the context of frothy bloat. In general, ARF showed a large number of negative interrelationships with ruminal bacteria in normal rumen conditions. However, development of frothy bloat decreased the total number of relationships between ARF and bacteria, implying a disruption of microbe-microbe interrelationships (i.e., dysbiosis). Collectively, this thesis provides novel insights into the contribution of rumen microbiota to common metabolic disorders of beef cattle.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".