135 SHORT-TERM OVARIAN EFFECTS OF UNILATERAL OVARIECTOMY IN COWS
Bibliographic record
Abstract
Classical studies established that the removal of one of the paired organs produces a compensatory effect on the remaining organ. In the bovine ovary this aspect has not been examined in detail. We took advantage of follicular and luteal profiles from a previous study to retrospectively examine the effects of ovariectomy before and after ovulation on follicular dynamics of the remaining ovary in cattle. To characterise the prevalence and distribution of tyrosine kinase receptor A in the bovine ovary, the original design involved unilateral ovariectomy of cows at different stages of the periovulatory period. For the purposes of the present study, we combined data into 2 groups, a preovulatory group (n = 6 cows) and a post-ovulatory group (n = 5 cows), to provide sufficient data for statistical interpretation. The cows were examined daily by transrectal ultrasonography to determine the ovarian status. For the preovulatory group, a luteolytic dose of prostaglandin was administered when the dominant follicle of the second follicular wave reached =10 mm, and the ovary containing the dominant follicle was removed within 48 h. For the post-ovulatory group, ovariectomy was performed on the ovary containing the newly formed corpus luteum between Days 2 to 6 (Day 0 = ovulation). Unilateral ovariectomy was performed by colpotomy under caudal epidural anaesthesia using a chain ecraseur. After ovariectomy, cows were examined daily by ultrasonography from ovariectomy to the completion of an interovulatory interval (period between 2 ovulations). Single-point data were compared between groups by t-test, and binomial data were compared between groups by Fisher’s exact test. Double ovulations were detected in 3/6 ovariectomized in the preovulatory period and 2/5 ovariectomized in the post-ovulatory period. The first ovulation after ovariectomy tended to occur earlier in the preovulatory group than in the post-ovulatory group (P = 0.08), which was attributed primarily to the development of oversized persistent dominant follicles (~20 mm in diameter for =7 days in absence of a corpora lutea) in 2 of 5 cows in the post-ovulatory ovariectomy group. The interovulatory interval after ovariectomy was shorter in the post-ovulatory group than in the preovulatory group (14.6 ± 0.3 v. 20.3 ± 0.6 days; P = 0.01). No distinct patterns were detected in follicular and luteal dynamics between the pre- and post-ovulatory ovariectomy groups. The number of follicles =3 mm detected by ultrasonography was greater in the post-ovulatory ovariectomy group than in the preovulatory group on Days 6, 7, 8, and 16 of the first interovulatory interval after ovariectomy. In conclusion, results of this retrospective study support the concept that follicular and luteal effects of removal of one ovary are influenced by the timing of ovariectomy relative to ovulation. A prospective study involving a comparison of ovarian dynamics of the same cows before and after unilateral ovariectomy will provide a better understanding of the disruption that take place and the mechanisms controlling it. Research was supported by the Natural Sciences and Engineering Research Council of Canada.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 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) | 0.000 | 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 teacher head, 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".