Effects of fat level and coconut-to-palm fat ratio in milk replacer on solid feed intake and performance of pre- and postweaning dairy calves
Notice bibliographique
Résumé
This study investigated the effects of varying fat levels and ratios of coconut to palm fat in milk replacer on solid feed intake and performance of male Holstein calves fed a high milk replacer allowance. Calves were individually housed and enrolled in a 91-d (study 1; n = 128) and 84-d (study 2; n = 128) experiment at the same research facility divided into 3 phases: preweaning (1-42 d), weaning (43-63 d), and postweaning (64-study end). In study 1, calves were randomly assigned to 1 of the 3 treatments, consisting of a milk replacer containing a spray-dried blend of 20% coconut to 80% palm fat with: (1) low fat (17%; LF-17%; n = 42; BW = 47.64 ± 2.62 kg), (2) moderate fat (23%; MF-23%; n = 43; BW = 47.69 ± 3.42 kg), and (3) high fat (29%; HF-29%; n = 41; BW = 47.04 ± 3.74 kg) in relation to 26% CP level. In study 2, calves were randomly assigned to 1 of the 3 treatments with the same fat-to-CP ratio (21% fat; 26% CP), varying the ratio of coconut to palm fat in the spray-dried fat blend with: 1) 20% to 80% (20C:80P; n = 42; BW = 47.63 ± 4.40 kg), 2) 35% to 65% (35C:65P; n = 42; BW = 49.07 ± 5.30 kg), and 3) 50% to 50% (50C:50P; n = 44; BW = 48.48 ± 4.09 kg), respectively. Milk replacer was fed twice daily (130 g/L) following the step-up, step-down program: from d 0 to 6, 520 g/d; d 7 to 13, 650 g/d; d 14 to 20, 910 g/d; d 21 to 41, 1,040 g/d; d 42 to 48, 910 g/d; d 49 to 63, 650 g/d. Body weight and calf starter intake were recorded weekly. Mixed linear models were used with treatment, phase, and their interaction included as fixed effects. Initial BW, serum total protein, calf source, and total number of disease interventions were tested as covariates. In study 1, ADG was greater for calves fed a low-fat milk replacer over the 91-d period (LF-17% = 1.24 ± 0.02, MF-23% = 1.09 ± 0.02, HF-29% = 1.12 ± 0.03 kg/d). At 91d, BW was greater for LF-17% (LF-17% = 160.80 ± 2.11, MF-23% = 147.22 ± 2.17, HF-29% = 149.59 ± 2.26 kg). Total DMI was greater for LF-17% calves across the postweaning phase, leading to greater ME intake (LF-17% = 14.15 ± 0.22, MF-23% = 11.98 ± 0.22, HF-29% = 12.31 ± 0.23 Mcal/kg). During preweaning, LF-17% calves had greater feed energy efficiency. In study 2, ADG was greater for 35C:65P calves over the total period (20C:80P = 1.04 ± 0.02, 35C:65P = 1.11 ± 0.02, 50C:50P = 1.04 ± 0.02 kg/d). At d 84, BW was greater for 35C:65P dairy calves (20C:80P = 135.82 ± 1.97 kg; 35C:65P = 141.63 ± 2.01 kg; 50C:50P = 136.25 ± 1.87 kg). These findings suggest that lower levels of fat in milk replacer, formulated with a spray-dried 20% coconut-to-80% palm fat blend, promote solid feed intake and overall performance. A spray-dried blend with a ratio of 35% coconut to 65% palm fat, included at 21% DM, appears to be a more favorable ratio in supporting calf performance.
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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) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 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 ».