Response of early weaned piglets to graded levels of dietary cobalamin
Bibliographic record
Abstract
The water-soluble vitamin cobalamin plays a central role as a co-factor in key pathways of energy and protein metabolism. The dietary requirement of this vitamin for the young pig (5–10 kg) has been estimated at 17.5 μg kg-1, but it is derived from estimates made over 40 yr ago. In light of changes in swine production, including the selection for high lean potential genotypes and the move to earlier weaning times, a reassessment of the adequacy of current cobalamin estimates is warranted. To this end, two trials were conducted to test the following alternate hypothesis: The current National Research Council (NRC 1998) estimated cobalamin requirement for the 5- to 10-kg early-weaned piglet is inadequate to maintain optimal cobalamin status, as reflected by growth, feed conversion efficiency, plasma cobalamin and plasma homocysteine concentrations. In trial 1, 60 Cotswold pigs (17 ± 1 d, equal males and females) were randomly assigned to receive diets, formulated with ingredients essentially devoid of cobalamin, and containing either 0, 35, 70, 105, or 140 g crystalline cobalamin kg-1. After 15 d, growth, feed intake and feed conversion efficiency were not significantly different (P > 0.05) between the dietary cobalamin levels. However, plasma cobalamin was significantly lower (49.9 vs 186.7, 168.0, 164.7, and 178.7 pg mL-1; SEM 17.3; P < 0.05) and homocysteine was significantly higher (34.5 vs. 22.5, 26.0, 24.7, and 23.4 μmol L-1; SEM 2.9; P < 0.05) in piglets consuming diets containing 0 vs. 35, 70, 105 and 140 μg crystalline cobalamin kg-1, respectively. Trial 2 retained the same study design as trial 1, but added dietary cobalamin concentrations were equivalent to 0, 10, 20, 30, and 40 g kg-1. The observed pattern of responses in plasma cobalamin and homocysteine support a requirement of added cobalamin in excess of 30 μg kg-1 of diet. Taken together, the data support a requirement for the addition of 35 μg crystalline cobalamin kg-1 of a diet formulated with ingredients essentially devoid of natural cobalamin for the early-weaned piglet between 5 and 10 kg, a value that is double the current NRC requirement. In addition, the current study uses changes in the plasma concentration of the metabolite homocysteine as a novel approach for the estimation of the dietary requirement for cobalamin in animals. Key words: Cobalamin, early weaned pig, homocysteine, dietary requirement
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| 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".