Physiological, cytological, and reproductive hormone characterization of estrus in Pasundan heifers synchronized with double injection of prostaglandin F2α
Bibliographic record
Abstract
Background and Aim: Pasundan cattle, a native Indonesian breed with valuable reproductive traits, face population decline due to limited conservation efforts. Estrus synchronization using prostaglandin F2α (PGF2α) is a viable strategy to support genetic improvement and sustainable breeding. This study aimed to evaluate the physiological, cytological, and hormonal responses associated with estrus synchronization in Pasundan heifers following a double-injection protocol of PGF2α. Materials and Methods: Eighteen healthy Pasundan heifers (2.0–2.5 years old; body condition score 3) received two intramuscular PGF2α injections 11 days apart. Estrus signs were assessed through vulva morphology, cervical mucus viscosity, and vaginal electrical resistance (VER) on days 0, 4, 5, 11–15. Vaginal cytology was conducted to classify epithelial cells, and blood samples were analyzed for follicle-stimulating hormone (FSH), progesterone, and estradiol through enzyme-linked immunosorbent assay. Data were analyzed using one-way analysis of variance with Tukey’s post hoc test (p < 0.05). Results: The peak estrus response occurred on day 14 post-initial injection, marked by maximal vulvar swelling (7.27 ± 1.15 cm), highest mucus viscosity (14.9 ± 3.00 mm), and lowest VER (198.67 ± 29.61 Ohms). Cytologically, superficial and keratinized epithelial cells dominated (64.22%), indicating estrus. Hormonal assays revealed elevated FSH (5.08 mIU/mL) and estradiol (0.214 pg/mL), alongside a nadir in progesterone (0.162 ng/mL). Estrus was observed in 88.89% of heifers on day 14. Conclusion: Double-injection PGF2α effectively synchronized estrus in Pasundan heifers, with day 14 being optimal for fixed-time artificial insemination (FTAI). The synchronization protocol demonstrated clear correlations between physical, cytological, and hormonal parameters. This protocol provides a reliable basis for reproductive management in Pasundan cattle, facilitating conservation and productivity. Future studies should assess conception outcomes post-FTAI to validate long-term reproductive efficiency. Keywords: estrus synchronization, fixed-time artificial insemination, Pasundan cattle, prostaglandin F2α, reproductive hormones, vaginal cytology.
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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".