Risk evaluation for bovine embryo transfer services using computer simulation and economic decision theory

A mathematical model was used to evaluate the dynamics and risks in bovine embryo transfer. Variables included embryo collection, fertilization, and transfer rates, plus overall pregnancy rates. Decision analysis was applied to three sets of 500 simulated flushes to test three strategies: 1) nonsuperovulation, 2) superovulation using follicle stimulating hormone (FSH) and 3) superovulation using pregnant mare serum gonadotropin (PMSG). Model validation involved comparing model performance against standards derived from 39 published studies. The model's repeatability was +/- 0.10 against standards in 93% of cases, and never exceeded +/- 0.13 in all 1500 simulations. Model outcomes were accurate to +/- 3% using average results. No pregnancies occurred in 22% of nonsuperovulated donors, 8% of FSH superovulated donors, and 6% of PMSG superovulated donors. PMSG treatment averaged more pregnancies per flush than FSH treatment (4.4 vs 3.9) but showed greater variation in response (64 vs 51%). Decision analysis suggests that a PMSG-induced flush would net $105 more than an FSH-induced flush, and that either superovulation strategy would yield approximately 10 times the net income of a nonsuperovulated flush. Pricing by response (PMSG) or by transfer (FSH) is optimal for the provider of embryo transfer services.