485 Impacts of estrus expression and intensity during a fixed-time AI protocol on parameters associated with fertility and pregnancy success in beef cows
Bibliographic record
Abstract
In this experiment (d 0 to 41), 290 lactating, primiparous and multiparous non-pregnant Brangus cows received a 2 mg injection of estradiol benzoate and an intravaginal progesterone (P4) releasing device (CIDR) on d 0, a 12.5 mg injection of PGF2α on d 7, CIDR removal in addition to 0.6 mg injection of estradiol cypionate and 300 IU injection of eCG on d 9, and fixed-time AI on d 11. All cows were inseminated by the same technician with semen from a single bull. On d 7, cows were fitted with a pedometer behind their left shoulder. On d 9, an estrus detection patch was attached to the tailhed of each cow. On d 11, estrus was defined as removal of >50% of the rub-off coating from the patch. Cow activity (total steps) was calculated by subtracting d 7 to 9 results (basal activity) from d 9 to 11 results (expected estrus period). Cows were classified by estrus intensity according to physical activity as: NOESTRUS = cows that did not express estrus; or cows that expressed estrus with physical activity below (LOWESTRUS) or above (HIESTRUS) the population median. Ovarian transrectal ultrasonography was performed on d 11 and 18. Blood was collected concurrently with ultrasonography exams for plasma P4 analysis. Pregnancy status was verified by transrectal ultrasonography on d 41. Only data from cows that ovulated to the synchronization protocol and that were successfully classified according to estrus characteristics were utilized (NOESTRUS, n = 57; LOWESTRUS, n = 87; HIESTRUS, n = 90). Diameter of dominant follicle on d 11, CL volume on d 18, and plasma P4 concentrations on d 18 were greater (P ≤ 0.05) in HIESTRUS vs. LOWESTRUS and NOESTRUS, and also greater (P ≤ 0.05) for LOWESTRUS vs. NOESTRUS (14.1, 13.4, and 12.5 mm, SEM = 0.3; 5.5, 4.9, and 3.6 cm3, SEM = 0.5; and 4.7, 4.0, and 3.0 ng/mL; SEM = 0.2). Plasma P4 on d 11 were greater (P < 0.01) in NOESTRUS vs. HIESTRUS and LOWESTRUS, and similar (P = 0.36) between HIESTRUS and LOWESTRUS (0.47, 0.30, and 0.25 ng/mL; SEM = 0.07). Pregnancy rates were less (P ≤ 0.04) in NOESTRUS vs. HIESTRUS and LOWESTRUS, and similar (P = 0.38) between HIESTRUS and LOWESTRUS (42.0, 67.3 and 60.5, SEM = 7.1). Hence, estrus expression and intensity, estimated by physical activity after CIDR removal, impacted fertility parameters and pregnancy success in Brangus cows.
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".