Diet supplementation with a mixture of essential oils: Effects on enteric methane emissions, apparent total-tract nutrient digestibility, nitrogen utilization, and lactational performance
Notice bibliographique
Résumé
This study examined the effects of supplementing dairy cows with a mixture of essential oils on enteric CH 4 emissions, apparent total-tract nutrient digestibility, N utilization, and lactational performance (production, components, and efficiency).Thirty-two multiparous lactating Holstein cows were used in a randomized complete block design.Cows averaged (mean ± SD) 95 ± 15.4 DIM, 47.7 ± 4.51 kg milk yield, and 698 ± 68.2 kg BW at the start of the experiment.The experiment consisted of a 3-wk pretreatment period (i.e., covariate), followed by a 3-wk adaptation to the experimental treatments, and a 10-wk period for data and sample collection.At the beginning of the study, milk yield and DIM data were used to block the cows into 16 blocks of 2 cows each.Subsequently, the blocks were adjusted based on milk yield and enteric CH 4 emission data collected during the pretreatment period.Within each block, cows were assigned to 1 of 2 dietary treatments: (1) a basal diet supplemented with a placebo (control, no additive), or (2) a basal diet with the essential oil supplement (Agolin, 1 g/cow per day).The basal diet (i.e., TMR) was composed of 69.3% forage (corn and alfalfa silage and grass hay) and 30.7% concentrate, on a DM basis, and the essential oil mixture consisted mainly of coriander seed oil, eugenol, geraniol, and geranyl acetate.Twice daily, the essential oil supplement was thoroughly mixed with 50 g of a commercial protein supplement (i.e., carrier) and 500 g of the TMR and this premix (i.e., 550 g/ meal) was offered to the cow before the basal diet.No interactions between the essential oil supplement and the sampling week were observed for any of the response variables.Dry matter intake, apparent total-tract nutrient digestibility and N balance were unaffected by feeding the essential oil supplement.Yields of milk, 4% FCM, and ECM were not modified by the experimental treatment.Neither feed efficiency (kg milk/kg DMI, kg 4% FCM/kg DMI, kg ECM/kg DMI) nor dietary N use efficiency in milk N secretion (i.e., g milk N/g N intake) were affected by essential oil supplementation.Body weight change and BCS did not differ between cows fed the essential oil supplement versus cows fed the control.Daily enteric CH 4 production, CH 4 yield, and CH 4 intensity averaged 498 g/d, 18.4 g/kg of DMI, and 11.0 g/kg of ECM, respectively, and were unchanged by essential oil supplementation.We conclude that supplementing cows fed a high-forage diet with 1 g/d of this essential oil mixture did not positively affect lactational performance, nutrient digestibility, and N utilization, or reduce enteric CH 4 (production, yield, and intensity).More research is needed to identify the optimal dose of this essential oil mixture and elucidate how it may interact with the basal diet to improve the mixture's efficacy.
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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 | 0,001 |
| 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 | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| 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 ».