Effect of use and dosage of p-follicle-stimulating hormone for ovarian superstimulation before ovum pick up and in vitro embryo production in pregnant Holstein heifers

The benefit of ovarian superstimulation using exogenous FSH before ovum pick-up (OPU) and in vitro embryo production (IVEP) has been the subject conflicting results. objective present study, therefore, was to evaluate effect use dose porcine (p-FSH) OPU/IVEP on response pregnant heifers. Pregnant Holstein heifers (n = 48) were assigned randomly receive 0, 160, or 300 mg NIH-FSH-P1 a crossover design. Ovum performed at 49, 63, 77 d gestation with 14 “washout” between OPU sessions. Follicle ablation D 0 (p.m.) p-FSH treatments, consisting 4 decreasing injections administered 12 h apart, initiated 36 after follicle (D2 a.m.). Heifers underwent 5 (a.m.), 40 last treatment, cumulus oocyte complexes (COC) subjected IVEP procedures. Differences treatment groups evaluated generalized linear mixed models. There quadratic effects both number percentage small (<6 mm), medium (6–10 mm) large (>10 follicles. Number follicles increased increasing dosages, although magnitude change greater 160 mg, than p-FSH. Total follicles, COC recovered viable linearly dose. Conversely, there no evidence for an recovery nor COC. Cleavage percentage, cleaved oocytes, blastocyst blastocysts In conclusion, resulted superstimulatory competence which turn IVEP. Furthermore, these dependent such that up progressively yield.