171 Sex-Sorted Sperm Used for Fixed-Time Artificial Insemination and in Vitro Fertilization in Wood Bison
Bibliographic record
Abstract
Abstract Wood bison (Bison bison athabascae) are a threatened species native to Canada. In a conservation setting such as zoos, females are preferred over males and sex-sorted sperm may help skew the proportion of females born. The objective of this study was to determine the efficacy of sex-sorted sperm in fixed-time artificial insemination (FTAI, Experiment 1) and in vitro fertilization (IVF, Experiment 2). In Experiment 1, females in bison herds at the University of Saskatchewan and Toronto Zoo were synchronized with 3.3 mg estradiol-17ß + 50 mg progesterone and given a progesterone-releasing intravaginal device for 8 days. At device removal, bison were given 500 µg of cloprostenol, and 72 h later were given 2500 IU human chorionic gonadotropin (hCG) and inseminated with either sex-sorted or conventional sperm. A second insemination occurred 24 h after hCG. Pregnancy diagnosis and fetal sexing was done by transrectal ultrasonography at 30- and 70-days post-AI, respectively. In Experiment 2, cumulus oocyte complexes collected transvaginally from live bison were fertilized in vitro with either sex-sorted or conventional sperm. Cleavage and embryo rates were determined at 3- and 7-days post fertilization, respectively. Proportional data were compared by chi-square. In Experiment 1, there was no effect of herd (P=0.17) or sperm (P=0.68) on pregnancy per AI (P/AI) at 30 days (total=25/51 [49%]). The proportion of female calves was greater in the sex-sorted than conventional group (9/10 [90%] vs 3/11 [27%]; P< 0.01). In Experiment 2, the cleavage (122/222 [55%] vs 62/94 [66%];P=0.07) and embryo rate (18/222 [8%] vs 14/94 [15%]; P=0.07) tended to be lower in the sex-sorted than the conventional group. In summary, sex-sorted sperm increased the proportion of female bison calves born following FTAI. Future efforts will include improving embryo production rates following IVF with sex-sorted sperm. Funding provided by Toronto Zoo, Mitacs, and STGenetics.
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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 | 0.001 | 0.001 |
| 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".