Fig. 2

Ovarian follicular response to oestrous synchronisation. Response to PGF2α analogue treatment (twice, 11 days apart) followed by GnRH analogue induction of ovulation 48 h later in heifers and cows. a Distribution of time (h) to ovulation measured as time from GnRH analogue treatment to the final ultrasonography examination after ovulation minus 1.5 h and b distribution of diameter (mm) of the ovulating follicle (at the last ultrasonography measurement); two heifers did not ovulate