Carryover effects of pre- and postweaning planes of nutrition on reproductive tract development and estrous cycle characteristics in Holstein heifers
Bibliographic record
Abstract
The objectives of this study were to investigate the carryover effects of differing pre- and postweaning planes of nutrition on prepubertal reproductive tract development and postpubertal estrous cycle characteristics in Holstein heifers. Heifer calves (n = 36) were randomly assigned to receive either a low or a high (5 or 10 L of whole milk/d, respectively) preweaning diet from 1 to 7 wk of age and either a low or a high (70 or 85% of concentrate dry total mixed ration, respectively) postweaning diet from 11 to 25 wk of age. Starting at wk 26 of age, heifers were subjected to weekly transrectal ultrasonography until wk 33 or until first ovulation to assess endometrial thickness and ovarian follicular count and size in the prepubertal phase. In a subset of heifers (n = 28), ovarian ultrasonography continued weekly until at least the second ovulation was confirmed; thereafter, ovarian dynamics (through ultrasonography) and blood progesterone (P4) were assessed every 2 d throughout 1 complete estrous cycle in the postpubertal phase. In the prepubertal phase, endometrial thickness (12.0 ± 0.4 vs. 10.8 ± 0.3 mm) and largest follicle size (11.8 ± 0.3 vs. 10.9 ± 0.2 mm) were greater in heifers fed the high postweaning diet than in those fed the low postweaning diet. Furthermore, the number of class 2 (6-9 mm) follicles was greater in heifers fed the high preweaning diet than in those fed the low preweaning diet (1.6 ± 0.1 vs. 1.1 ± 0.1), whereas the number of class 3 (>9 mm) follicles was greater in heifers fed the high postweaning diet than in those fed the low postweaning diet (1.2 ± 0.1 vs. 1.0 ± 0.1). In the postpubertal phase, overall corpus luteum and P4 dynamics did not differ among pre- or postweaning treatments; however, P4 at 4 d preceding luteolysis was lesser in heifers fed the high postweaning diet than in those fed the low postweaning diet (6.1 ± 0.4 vs. 7.7 ± 0.4 ng/mL). In addition, compared with heifers fed the low postweaning diet, those fed the high postweaning diet had a greater number of antral follicles (31.4 ± 2.2 vs. 21.4 ± 2.3) and tended to have more class 3 follicles (3.6 ± 0.3 vs. 2.7 ± 0.3). Results indicate positive carryover effects of increasing the preweaning plane of nutrition from 5 to 10 L of whole milk/d on prepubertal follicular growth in Holstein heifers. Furthermore, an increased postweaning plane of nutrition (85 vs. 70% of concentrate dry total mixed ration) advanced reproductive development through greater endometrial thickness and follicular growth in the prepubertal phase and increased the population of antral follicles in the postpubertal estrous cycle.
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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 | 0.001 |
| 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 | 0.001 |
| 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".