1321 Comparison of flax oil with varying lipid supplements in dairy ration: A meta-analysis
Bibliographic record
Abstract
Feeding flax oil, a source of trienoic fatty acids (TRI-FA), to dairy cows contributes to improve fertility, reduce methane emissions and increase milk fat content of n-3 FA. However, studies on the effect of flax TRI-FA on milk production and composition have yielded contradictory results. The objective of this meta-analysis was to evaluate the effects of flax TRI-FA on lactation performance when compared with different sources of dietary lipids in which dienoic (DI), monoenoic (MONO), or saturated (SAT) FA were predominant. Three databases including 30, 20, and 15 studies, published between 1998 and 2015, were used for the comparisons of flax TRI-FA vs. DI-FA, vs. MONO-FA, and vs. SAT-FA supplements, respectively. For each database, dairy cow performance was adjusted with a linear mixed model where lipid source and supplemental lipid concentration were the independent variables, and study effect was included as a random variable. Concentrations of supplemental lipids, determined by ether extraction, varied from 0.7 to 6.0% (DM basis) for flax TRI-FA (3 databases combined), 0.5 to 6.6% for DI-FA, 0.9 to 5.9% for MONO-FA, and 1.0 to 4.1% for SAT-FA supplements. The interactions between lipid sources and their dietary concentrations were never significant and were removed from the models. Feeding flax TRI-FA tended to increase DMI (0.38 kg/d; P = 0.07) compared with SAT-FA, but no difference was observed with DI-FA or MONO-FA supplements. Actual, fat corrected, and energy corrected milk yields were not different between flax TRI-FA and the lipid categories evaluated. Feed efficiency of cows receiving flax TRI-FA was lower (−0.03 kg milk/kg DMI) compared with SAT-FA (P = 0.03), whereas no difference was observed with DI-FA and MONO-FA supplements. Milk fat and protein concentrations and yields were not different between flax TRI-FA and the other three lipid categories. Feeding flax TRI-FA increased lactose concentrations compared with DI-FA and SAT-FA supplements by 0.02 (P = 0.03) and 0.03 (P = 0.03) percentage unit, respectively. Despite minor effects on lactose, there was no difference between flax TRI-FA and other dietary unsaturated lipids on animal performance. Nevertheless, as a result of an increase in DMI, efficiency of milk production was reduced by feeding flax TRI-FA compared with SAT-FA supplements.
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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 | 0.010 | 0.016 |
| Meta-epidemiology (narrow) | 0.003 | 0.002 |
| Meta-epidemiology (broad) | 0.014 | 0.047 |
| Bibliometrics | 0.003 | 0.004 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.005 | 0.001 |
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".