15 EFFECT OF DOSE OF ESTRADIOL VALERATE ON OVARIAN FOLLICULAR DYNAMICS IN CIDR-TREATED BEEF COWS
Bibliographic record
Abstract
The objective was to investigate the effect of dose of estradiol valerate (EV) on ovarian follicular growth profiles, intervals to follicular wave emergence and, following CIDR removal, estrus and ovulation in beef cows. On Day 0, 43 non-lactating, crossbred beef cows, 3 to 9 yr of age and at random stages of the estrous cycle, received a CIDR (Bioniche Animal Health; Belleville, Ontario, Canada) and were randomly allocated to one of four groups to receive no further treatment (Control; n = 10), or an injection of 1 mg (n = 11), 2 mg (n = 10), or 5 mg (n = 12) i.m. of EV (Sigma Chemical Co, St. Louis, MO, USA) in 2 mL canola oil. On Day 7, CIDR were removed and cows received 500 µg i.m. of cloprostenol (Estrumate, Schering Plough Animal Health, Pointe-Claire, Quebec, Canada). Ovaries were examined by transrectal ultrasonography once daily until 48 h after CIDR removal to detect ovarian follicle growth profiles, and twice daily thereafter to detect ovulation. Data were analyzed by ANOVA (LSD and Bartlett’s tests) and chi-square procedures. One cow (5 mg EV group) lost the CIDR and was removed from all analyses. There was an effect of day (P < 0.0001) on CL diameter, but the effects of treatment (P = 0.3), and the treatment-by-day interaction (P = 0.1), were not significant. Follicular wave emergence occurred within 7 d in 7/10 (70%) Control cows and 31/32 (97%; P < 0.04) EV-treated cows (one cow in late diestrus at the time of treatment did not respond to 1 mg EV). Mean (±SD) interval from treatment to wave emergence was longer (P < 0.03) in cows treated with 5 mg EV (4.8 ± 1.2 d) than in those treated with 1 mg (3.2 ± 0.9 days) or 2 mg EV (3.4 ± 0.8 days), while Control cows were intermediate (3.8 ± 2.0 days). Although follicular wave emergence tended (P < 0.09) to be more synchronous in cows receiving EV, intervals from CIDR removal to estrus (P = 0.7) and ovulation (P = 0.8) did not differ among groups. Diameter of the dominant follicle was smaller (P < 0.04) at CIDR removal and tended to be smaller (P < 0.08) just prior to ovulation in the 5 mg EV group (8.5 ± 2.2 and 13.2 ± 0.6 mm, respectively) than in the Control (11.8 ± 4.6 and 15.5 ± 2.9 mm, respectively) or 1 mg EV (11.7 ± 2.5 and 15.1 ± 2.2 mm, respectively) groups, with the 2 mg EV group (10.7 ± 1.5 and 14.3 ± 1.7 mm, respectively) intermediate. Diameter of the dominant follicle at CIDR removal was less variable (P < 0.01) in the 2 and 5 mg EV groups than in the Control group and intermediate in the 1 mg EV group. In summary, dose of EV affected follicular dynamics, interval to and synchrony of follicular wave emergence, and dominant follicle diameter at CIDR removal and just prior to ovulation in CIDR-treated cows. However, interval from CIDR removal to estrus and ovulation was not affected by treatment. Results suggest that a dose of 2 mg EV may be most efficacious in synchronizing follicular wave emergence in CIDR-treated cows.
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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) | 0.001 | 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".