Impact of a reduced metabolizable protein supply during the transition period on the immune and metabolic status of dairy cows
Notice bibliographique
Résumé
During the transition period, the incidence of diseases increases due to a negative energy balance that affects metabolic and immune status. Limiting milk production at the beginning of lactation by milking once a day or by incompletely milking twice a day improves the metabolic and immune status of cows. Previous studies have shown that milk production is highly responsive to additional MP. Therefore, reducing MP intake could provide an alternative strategy. This study evaluated whether reducing the MP supply during the transition period could limit milk yield temporarily and thereby improve the cows' metabolic and immune status. A first group of cows (n = 11, 80% MP) was fed a diet formulated to supply 80% of their MP needs during the treatment period (from 10 d before expected calving to 14 DIM) while they received a diet formulated to supply 100% of their MP needs before treatment (adaptation, d 28 to d 11 before expected calving) and after (follow-up, 15 to 28 DIM) the treatment period. A second group of cows (n = 12, 100% MP) was fed a diet formulated to supply 100% of their MP needs during the 3 periods. Blood samples were taken on average at d 26 ± 3.6; d 19 ± 3.7; d 12 ± 3.6; d 9 ± 3.6 before calving and at 2, 5, 7, 10, 14, 21, and 28 DIM to assess the metabolic and immune status. Milk samples were collected at the same frequency to assess milk composition. The milk production of the 80% MP cows was numerically smaller than that of the 100% MP cows (2.4 kg/d) from d 0 to 14, but not after the MP restriction ended. The 80% MP cows had numerically more plasma BHB during the treatment period than the 100% MP cows (694.6 vs. 574.0 ± 389.8 µM, respectively). The 80% MP cows had significantly less glucose on d 7 and d 10 than the 100% MP cows (3.14 vs. 3.44 ± 0.06 and 3.15 vs. 3.42 ± 0.07 mM, respectively). Throughout the 3 experimental periods, no differences were observed for nonesterified fatty acids or for some of the markers of the mobilization of muscle reserves. However, the concentration in 3-methyl-His was greater for the 80% MP cows during treatment and was not different during the follow-up period. The PMN oxidative burst of the 80% MP cows was numerically greater during treatment and on d 21. The treatment did not alter the proliferation of peripheral blood mononuclear cells or PMN phagocytosis capacity. In conclusion, a 20% reduction in MP supply during the transition period did decrease milk production, but this decrease was not sufficient to improve energy balance and to reduce metabolic and immune disturbances.
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 | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 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 ».