Differential average daily gain of pregnant Holstein × Gyr dairy heifers causes placental adaptations to support fetal growth and development
Bibliographic record
Abstract
This study aimed to evaluate the effects of differential average daily gain targets of dairy heifers throughout gestation on placental hemodynamics, uterine involution, colostrum production of the heifers, and effects on newborn calf weight and immunity transfer. Fourteen Holstein × Gyr heifers with an average body weight of 446 ± 46.7 kg and age of 25 ± 3.9 mo were randomly assigned to the following treatments: moderate body weight gain (MOD, n = 7), where heifers were fed to achieve 0.50 kg/d; and high body weight gain (HIG, n = 7), where heifers were fed to achieve 0.75 kg/d. Target average daily gains were established based on common tropical dairy production systems. The heifers received a total mixed ration feed twice daily starting at 70 d of gestation. Placentome vascularization was assessed using a color Doppler ultrasound at 180, 210, and 240 d of gestation. After calving, cotyledons were counted and sampled to analyze the mRNA expression of placental angiogenesis markers. After birth, calves were weighed and fed colostrum, and transfer of passive immunity efficiency was assessed. A significant increase in cotyledons was detected for MOD placenta soon after expulsion (81.5 ± 12.91 vs. 63.6 ± 10.52). Placentome vascularization at the final third of gestation increased for MOD heifers compared with HIG. Greater mRNA expression after membrane expulsion of VEGFB and IGFR1 in cotyledons and a greater estradiol concentration in circulation 1 d before calving was found for MOD heifers compared with HIG heifers; however, uterine involution postpartum was not different between treatment groups. Greater colostrum production was observed in HIG heifers (3.9 ± 1.05 vs. 2.2 ± 1.57 L) but with lower quality (25.2 ± 0.51 vs. 29.5 ± 0.65 Brix). No differences were observed in birth weight or transfer of passive immunity efficiency between treatments; however, HIG calves had significantly greater vitality scores than MOD calves. The results of this study indicate that a moderate feeding regimen enhances placental blood flow by increasing angiogenesis, which suggests improved nutrient transfer to the fetus without major effects on its development during the neonatal stage, colostrum production, or uterine involution in the heifers.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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".