An in vivo stable isotope–based approach for assessment of absorbed amino acids from individual feed ingredients within complete diets
Notice bibliographique
Résumé
Accurate assessment of the nutritional content of feed ingredients is required for precise diet formulation. Characterizing ingredients in terms of absorption and digestibility of individual AA is challenging, and this information often relies on indirect methods. The purpose of this research was to evaluate an in vivo stable isotope–based method of determining plasma entry rates of individual AA from feather meal (FM), blood meal (BM), and a rumen-protected AA (RPMet). Abomasal infusions of unprotected Ile, Leu, Met, and sodium caseinate were used as control treatments to assess technique reliability and accuracy. Isotopic enrichment of plasma AA in response to a 2-h constant jugular infusion of a mixture of 13 C labeled AA was measured and modeled using a dynamic 4-pool model, which was fitted to each AA by infusion to derive diet entry rates. The resulting entry rate matrix was used to derive plasma entry rates of individual AA from each ingredient by regression. The mean of plasma AA entry for abomasally infused Ile, Leu, and Met was 93.4 ± 7.35% of that infused, indicating that 6.6% was used by splanchnic tissues during first pass. The mean of the plasma essential AA entry for abomasally infused casein was 86.7 ± 4.81% of that present in the source protein, which represents a mean of 8.7% first-pass use assuming 95% digestibility. Individual AA appearances ranged from 86 to 93% of the source content except Ile, which was 73%. These fractional appearance percentages were similar to those previously reported when using a dietary regression approach. The mean plasma essential AA entry rate for FM was 52.7% of the AA in the source ingredient, with a range across AA of 48 to 58%. The mean plasma essential AA entry rate for BM was 47.5%, with a range of 30 to 61%. However, estimated Met availability from the RPMet was lower (9.9%) than expected (42%). This may be due to the relatively larger errors of measurement for Met entry rates and a small change in RPMet inclusion. Assuming that rumen-undegraded protein absorption is reflective of aggregated essential AA entry rates after correction for first-pass use, 52.6 and 61.2% of dietary FM and BM CP was absorbed from the intestine, respectively, which yielded an estimated intestinal digestibility of 70 and 66%, respectively. This method appears to provide an accurate and precise in vivo assessment of individual AA plasma entry rates that can be used to better characterize individual feed ingredients in ruminants. Such information will result in more robust economic assessments of feeds and increased precision of diet formulation.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».