Methionine-hydroxy analogue was found to be significantly less bioavailable compared to dl-methionine for protein deposition in growing pigs
Bibliographic record
Abstract
When methionine (Met) is limiting in swine diets, it is commonly supplemented by using anhydrous dl-methionine (DLM, 99% purity) or liquid dl-methionine-hydroxy analogue free acid (MHA-FA, 88% purity). The objective of this experiment was to test the null hypothesis that the bioavailability of DLM and MHA-FA were not different for growing pigs, using the indicator amino acid (AA) (phenylalanine, Phe) oxidation (IAAO) method in a slope-ratio assay. Six barrows (mean BW during study: 21.1 kg) received seven dietary treatments with all pigs receiving all diets in random order at an intake of 95 g/kg BW0.75. The basal diet (BD) contained analyzed content of 15.1% CP, 0.20% Met, 0.73% Phe and all other AA in excess of requirement. The BD was supplemented with three graded levels of DLM or MHA-FA on an equimolar basis. Dietary treatments only varied in Met content and included: (i) BD, (ii) BD + 0.034% DLM, (iii) BD + 0.054% DLM, (iv) BD + 0.086% DLM, (v) BD + 0.029% MHA-FA, (vi) BD + 0.078% MHA-FA and (vii) BD + 0.107% MHA-FA, as analyzed. Indicator AA oxidation was determined during 4 h studies, where pigs were fed half-hourly meals each equal to 1/32 of their daily feed allowance. Each meal was mixed with 258.7 kBq (s.e. 2.6) of l-[1-14C]Phe with a prime of 3.5 times the half-hourly dose added to the first meal. The slope of the decrease in IAAO calculated by linear regression analysis was greater (P = 0.012) for DLM supplementation (9.87 ± 1.450 per g, 1.488 ± 0.215% per mmol) than for MHA-FA (6.48 ± 0.89 per g, 1.107 ± 0.152% per mmol). The ratio of slopes indicated a bioavailability of MHA-FA on a product basis, relative to DLM, of 65.7%. Bioavailability on an equimolar Met basis, calculated from the ratio of the slopes was 74.4% for MHA-FA, relative to DLM. In conclusion, these results indicate that the metabolic bioavailability of MHA-FA for growing pigs is appreciably lower than that of DLM on both an equimolar and a product basis.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 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".