367 INFLUENCE OF SUPERESTIMULATION AND HORMONAL DEPRIVATION PROTOCOLS ON IN VITRO PRODUCTION OF NELORE EMBRYOS (BOS TAURUS INDICUS)
Bibliographic record
Abstract
There are indications in the literature that delaying the period between ovarian superestimulation and ovum pickup (OPU) will induce follicles to a condition of initial atresia, which could be beneficial to oocyte development. Blondin et al. (2002 Biol. Reprod. 66, 38–43) superstimulated (FSH) Holstein heifers and delayed OPU for 48 h, i.e. they induced initial atresia in these follicles deprived of FSH (starvation) for 48 h. Additionally, 6 h before OPU, LH was administered to accelerate follicular maturation. This protocol yielded a surprisingly high blastocyst rate (80.4 ± 9.4%). In the present work, Blondin’s protocol was simultaneously compared to other protocols used for OPU and in vitro production of embryos (IVP), in Nelore cattle. Nelore cows (n = 18) were randomly allocated in three groups: Group 1 (just OPU), Group 2 (superestimulation and OPU), and Group 3 (superestimulation associated with FSH deprivation and OPU). Three OPU were performed, and the animals were switched to a different group each time in such a way that at the end of the experiment all cows received the three protocols. At a random stage of the estrous cycle (D2), follicles =6 mm were aspirated to induce a new follicular wave 2 days afterward (D0). In Group 1, OPU was performed on D2 and oocytes were processed to IVP. In Group 2, starting on D0, cows were superestimulated (pFSH, Folltropin®, 30 mg administered daily, IM, during 3 consecutive days; Bioniche Animal Health, Belleville, Ontario, Canada), and 6 h after the last FSH dose they received exogenous LH (12.5 mg, Im, Lutropin®, D3; Bioniche Animal Health). OPU was performed 6 h after LH administration, i.e. 12 h after the last dose of FSH. Animals in Group 3 received the same treatment as in Group 2, except that LH was administered 36 h after the last dose of FSH, and OPU occurred 6 h later. Therefore, in this Group, follicles were deprived of FSH during 48 h. Both cleavage and blastocyst rates were similar (P > 0.05, logistic regression) among oocytes from Groups 1, 2, and 3, respectively: 77.4% (144/185) and 42.70% (79/185); 75.54% (105/139) and 31.65% (44/139); 63.52% (101/159) and 33.33% (53/159). However, hatched blastocyst rate was higher (P < 0.01) in Group 1 (30.27%, 56/185) when compared to Group 2 (11.51%, 16/139) or 3 (15.72%, 25/159). It is concluded that, contrary to previous work on European breeds (taurus), ovarian superestimulation associated with deprivation of FSH and OPU (Group 3) do not increase IVP of Nelore embryos (indicus). Additionally, the highest hatched blastocyst rates were observed in oocytes from non superstimulated cows (Group 1).
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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".