0381 Genetic parameters for number of embryos produced by superovulated donors as heifers or cows using an in vivo or in vitro technique
Bibliographic record
Abstract
Genetic gain in a population can be improved by using multiple ovulation and embryo transfer (MOET) in elite females. Multiple embryos can be produced using two different techniques, either using superovulation and producing the embryos in vivo or using ovum pickup (OPU) and in vitro production (IVP) of the embryos. Moreover, embryos can be produced by donor cows or virgin heifers as young as 7 mo of age. The objectives of this study were to assess the genetic parameters for the number of embryos produced by Holstein donors superovulated either in vivo or in vitro and for the number of embryos produced by donors either as a cow or a heifer at embryo recovery. Data was provided by Holstein Canada and contained the number of viable embryos from every successful flushing performed across Canada. After editing, 137,446 records of superovulation performed on 54,463 donors between 1992 and 2014 provided information about the type of technique used, and 130,252 records from 51,323 donors provided information about the status of the donor (heifer or cow) at embryo recovery. Bivariate repeatability animal model analyses were performed. Heritability estimates for the donor were between 0.135 (0.007) and 0.155 (0.038), whereas estimates for the service sire were close to zero (from 0.004 ± 0.002 to 0.019 ± 0.010), indicating that the number of embryos produced is influenced by the genetic potential of the donor and not by the service sire. Moreover, moderate repeatability estimates indicated that the number of embryos produced should be somewhat consistent within a donor. Genetic correlations found for the number of embryos produced using either type of technique was strong (0.834 ± 0.094) for the donor, but not significant for the service sire (−0.202 ± 0.234). For the number of embryos produced by either a heifer or a cow, the genetic correlations were 0.702 (0.058) for the donor and 0.699 (0.206) for the service sire. Overall, our results suggest that the number of embryos produced by a superovulated donor should be similar regardless of the technique (in vivo or in vitro) used or the status (heifer or cow) of a donor at embryo recovery. On the other hand, using the same service sire will not increase similarity between the two techniques, but could influence the number of embryos produced by a donor as a heifer or as a cow in a similar way.
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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 | 0.002 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| 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) | 0.004 | 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".