PSIV-30 Moderate maternal nutrient restriction in beef heifers reduces fetal crown-rump length at day 35 of gestation
Bibliographic record
Abstract
Abstract One-carbon metabolite (OCM) supplementation in beef cattle has been shown to be a novel strategy that alters programming outcomes in tissues of the developing fetus. However, information regarding growth changes to the fetus during early gestation is limited. The objective of this study was to evaluate the effects of OCM supplementation in control-fed or nutrient-restricted pregnant heifers on fetal crown-rump length (CRL) during early gestation. We hypothesized that decreased nutrient availability in the maternal system would impact the growth of the fetus in utero and providing OCM supplementation would restore growth levels in a nutrient restricted environment. Angus crossbred heifers [n = 216; initial body weight (BW) = 365 ± 5.45 kg] across three replicates underwent estrus synchronization and bred via artificial insemination (AI) using female-sexed semen from a single sire. At breeding (d 0), heifers were assigned to treatments in a 2 × 2 factorial design, which included two levels of daily gain; control (CON; +0.45 kg/d gain) or restricted (RES; −0.23 kg/d gain) and supplementation of OCM [+OCM; rumen protected choline (44.4 g/d) and methionine (7.4 g/d) in a ground corn carrier and weekly injections of 320 mg folate and 20 mg vitamin B12] or no supplementation (-OCM; corn carrier and saline injections). Heifers were weighed weekly, and diets were adjusted on a dry matter basis of the total mixed ration to maintain targeted gain. Treatments were maintained through d 63 of gestation in pregnant heifers. Pregnancy diagnosis and fetal CRL was determined via transrectal ultrasonography on d 35. A total of 103 heifers were confirmed pregnant (replicate 1, n = 37; replicate 2, n = 32; replicate 3, n = 34). Data were analyzed using the MIXED procedures of SAS as a 2 × 2 factorial including the effects of two levels of gain, two levels of OCM treatment, replicate, and their two-way and three-way interactions. There were no three-way interactions between gain × treatment × replicate. However, there was a gain × treatment interaction (P ≤ 0.05), in which fetuses from RES heifers with and without OCM supplementation had reduced CRL compared with fetuses from CON heifers that did not receive OCM (14.15 ± 0.21 mm, 13.88 ± 0.21 mm, 14.84 ± 0.21 mm, respectively). Fetal CRL from OCM supplemented CON heifers was similar (P = 0.06) to all other treatments (14.27 ± 0.21 mm). In conclusion, fetuses from RES heifers exhibited a decreased CRL, and OCM supplementation did not mitigate these effects.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".