108 THE EFFECTS OF FORSKOLIN ON BRAHMAN IN VIVO-PRODUCED EMBRYOS AND SUBSEQUENT PREGNANCY RATES POST-THAW
Bibliographic record
Abstract
It has been hypothesised that lower survival rates post-thaw of Brahman (BR) embryos is due in part to higher intracellular lipids. The objective of this study was to determine whether pregnancy rates of in vivo–produced BR embryos could be enhanced by exposing them to 10 µM of forskolin (FSK; lipolytic agent) before slow cool freezing, thawing and direct transfer. A previous report (Phase II) indicated that the addition of FSK to culture 24 h before freezing 7 days in vitro–produced, BR-sired embryos can increase survival and blastocyst hatching rates (Pryor et al. 2010 Reprod. Fertil. Dev.22, 214). For this study (Phase III), 11 BR cows were injected with 25 mg of Lutalyse® (Pfizer Animal Health, New York, NY, USA) to synchronize oestrus. On Day 0 (7 days after synchronized oestrus), all donors were inserted with a CIDR (Controlled Intravaginal Releasing Device; Pharmacia Co., Kalamazoo, MI, USA) and injected with 50 mg of progesterone plus 2.5 mg of oestradiol 17 ß (Medshop, Longview, TX, USA). On Day 4, decreasing doses of Folltropin (Bioniche, Pullman, WA, USA) ranging from 160 to 264 mg were given twice daily for 3 days along with 0.625 mg of cloprostenol (Estrumate; Merck/Schering-Plough Animal Health, Whitehouse Station, NJ, USA) given twice on Day 6 (AM and PM) and CIDR removal on Day 7 AM. Donors were artificially inseminated 12 and 24 h post-oestrus (oestrus = Day 8) with frozen/thawed BR semen. On Day 14 (embryo age 6 days), donors were nonsurgically collected, producing a total of 75 grade-one morulae, which were randomly allocated and cultured for 24 h in Evolve (Zenith Biotechnology, Canada) supplemented with 4 mg mL–1 of Probumin BSA (Millipore, Norcross, GA, USA; control) or with FSK (Sigma, St. Louis, MO, USA) at 38.5°C under a 5% CO2, 5% O2 and 90% N2 humidified atmosphere. Immediately following treatment, 7 days compact morula/blastocysts were washed in Vigro Holding Plus medium (Bioniche, Belleville, Ontario, Canada) and submitted to Vigro Ethylene Glycol Freeze Plus medium (Bioniche) for 5 to 7 min before being frozen at 0.5°C min–1 from –6°C to –32°C and plunged in liquid nitrogen. Frozen embryos (n = 35 FSK; n = 35 control) were air thawed for 7 s and then immersed in 30°C H2O for 10 s before being nonsurgically transferred into synchronized recipients. Pregnancy rates were assessed by ultrasonography via rectal palpation 30 to 60 days post-transfer. Contingency analysis was performed using forskolin treatment, technician and embryo stage and location as independent variables (JMP 8.0, SAS Institute Inc., Cary, NC, USA). There were no statistical differences or interactions for any of the analysed variables. Pregnancy rates between control and FSK treatments did not vary (34.3 and 31.4%, respectively; chi-square P = 0.80). In conclusion, treating in vivo–produced BR embryos with 10 µM of forskolin for 24 h did not alter pregnancy rates. The authors acknowledge support from the American Brahman Breeders Association.
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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 | 0.000 | 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) | 0.000 | 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".