The Role of Antral Follicle Count in OPU/IVEP Donor Selection in Holsteın Cattle

The aim of this study was to determine the effect of antral follicle number on oocyte yield and IVEP in Holstein breed donors. The study groups were constituted following ultrasonographic examinations conducted on 23 Holstein heifers at one-week intervals. The Low-AFC group (n = 8) comprised animals with an average antral follicles counts in the ovary of ≤ 15, as determined by ultrasonographic examination. The High-AFC group (n = 9) comprised animals with an average antral follicle number of ≥30. Oocytes were collected from animals in both groups four times, one week apart, any day of the estrous cycle. The oocytes were classified according to their morphological characteristics and subsequently incorporated into the in vitro embryo production process. The total and viable oocyte numbers were found to be significantly greater in the High-AFC group than in the Low-AFC group (P < 0.01). The number of blastocysts obtained per session was also greater in the High-AFC group (P < 0.01). No statistically significant difference was observed between the blastocyst and viable oocyte rates in the two groups. Consequently, oocytes and blastocysts were obtained from Holsetin donors with high antral follicle counts in greater numbers. It was thought that the number of antral follicles in Holstein breed donors could be employed as a parameter in donor animal selection to increase the success of OPU/IVEP.