Effects of feeding canola meal or wheat dried distillers grains with solubles as a major protein source in low- or high-crude protein diets on ruminal fermentation, omasal flow, and production in cows
Bibliographic record
Abstract
The objective of this study was to determine the effects of feeding canola meal (CM) or wheat dried distillers grains with solubles (W-DDGS) as the major source of protein in diets varying in crude protein (CP) content on ruminal fermentation, microbial protein production, omasal nutrient flow, and production performance in lactating dairy cows. Eight lactating dairy cows were used in a replicated 4×4 Latin square design with 29-d periods (21 d of dietary adaptation and 8 d of measurements) and a 2×2 factorial arrangement of dietary treatments. Four cows in 1 Latin square were ruminally cannulated to allow ruminal and omasal sampling. The treatment factors were (1) source of supplemental protein (CM vs. W-DDGS) and (2) dietary CP content (15 vs. 17%; DM basis). Diets contained 50% forage and 50% concentrate, and were fed twice daily at 0900 and 1600 h as total mixed rations for ad libitum intake. Dry matter intake and milk yield were unaffected by dietary treatments; however, milk yield in cows that were fed CM was numerically greater (+1.1 kg/d) when compared with cows fed W-DDGS. Feeding CM increased milk lactose content compared with feeding W-DDGS. Milk urea nitrogen and ruminal NH3-N concentrations were greater in cows fed the high-CP compared with those fed the low-CP diet. The rumen-degradable protein supply was greater in cows fed the high-CP when compared with those fed the low-CP diet when diets contained CM, whereas rumen-degradable protein supply was lower in cows fed the high-CP when compared with those fed the low-CP diet when diets contained W-DDGS. Total N flow at the omasal canal was not affected by diet; however, omasal flow of NH3-N was greater in cows fed CM when compared with those fed W-DDGS. The rumen-undegradable protein supply was greater in cows fed the low-CP when compared with those fed the high-CP diet when diets contained CM, whereas rumen-undegradable protein supply was lower in cows fed the low-CP when compared with those fed the high-CP diet when diets contained W-DDGS. Omasal flow of fluid-associated bacteria was greater and that of particle-associated bacteria tended to be greater in cows fed CM when compared with those fed W-DDGS; however, omasal flow of total microbial nonammonia N was unaffected by dietary treatment. Omasal flows of threonine and tryptophan were greater, whereas that of histidine and lysine tended to be greater in cows fed CM when compared with those fed W-DDGS. Our results show that when dairy diets are formulated to contain 15 or 17% CP, CM or W-DDGS can be used as the major source of protein and achieve similar levels of milk production.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".