1306 Feeding steers extruded flaxseed and hay in a total mixed ration or sequentially can have substantial effects on beef fat polyunsaturated fatty acids and biohydrogenation intermediates
Bibliographic record
Abstract
There has been growing interest in increasing the content of polyunsaturated fatty acid (PUFA; esp. α-linolenic acid, ALA) and their biohydrogenation intermediates (BHI) in beef, particularly trans 11–18:1 (VA, vaccenic acid) and cis 9, trans 11–18:2 (RA, rumenic acid) due to their potential positive health effects. However, high variability in PUFA and BHI have been found in beef between and within trials. The present trial was designed to determine if feeding steers extruded flaxseed (Linpro-R™; O&T Farms Ltd., SK, Canada) and hay (25% and 75%; DM basis) together as a total mixed ration (TMR), or sequentially (non-TMR) would result in different enrichments of PUFA and BHI in different beef adipose tissues. Forty-eight Continental crossbred steers (325 ± 16 kg SD) were stratified by weight to 6 pens of 8 steers, pens were randomized to either TMR or non-TMR and steers were fed ad libitum for 240 d. At slaughter, subcutaneous fat (SCF) and perineal fat (PRF) samples were collected, freeze dried and directly methylated with 0.5 M sodium methoxide, and analyzed by GC using a 100 m CPSil 88 capillary column. Data were analyzed as a one-way ANOVA using the PROC MIXED procedure of SAS with diet as the main factor and pen as the experimental unit. Treatment means were generated and separated using the LSMEANS and PDIFF options, respectively. Compared to TMR steers, non-TMR steers had greater proportions of PUFA, trans-18:1, conjugated linoleic acids, and conjugated linolenic acids in both SC (+9.7%, +9.8%, +43.4%, +63.7%) and PR (+14.1%, +10.5%, +52.9%, +75.6%). In SCF, the percentages of ALA, VA and RA were increased (P < 0.001) from 0.91%, 4.92% and 1.91% in TMR steers to 1.10%, 6.82% and 2.69% in non-TMR steers. In PRF, the percentages of ALA, VA and RA were increased (P < 0.001) from 0.89%, 7.29% and 0.72% in TMR steers to 1.06%, 10.32% and 1.13% in non-TMR steers. Our results suggest that the method of feeding PUFA sources (e.g., flaxseed) can profoundly affect the enrichment of PUFA and their BHI in beef fat. In addition, the enrichment of these fatty acids also depends on fat depot, with PRF having greater proportions of VA, while SCF being higher in RA, which is likely due to the greater delta-9 desaturation of VA to RA in SCF.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".