Predictors of the ovarian superstimulatory response and oocyte collection in prepubertal heifers

•A positive relationship between AFC and plasma AMH at the time of wave emergence in prepubertal calves.•Plasma FSH concentrations was neither correlated with AFC nor with AMH in prepubertal calves.•AFC and plasma AMH were predictive of the ovarian response following FSH treatment.•A higher AFC was observed in calves at 4 than at 7 mo of age.•A greater number and size of follicles were observed after 7 than after 4 d of FSH treatment.•A higher proportion of fully expanded COC was collected after 7 than after 4 d of FSH treatment.