engleski

Effedt of Donor Breed on Bovine Oocyte Recovery and in vitro Embryo Development after Ovum Pick up

Ultrasound guided transvaginal oocyte recovery, also known as ovum pick up (OPU), and in vitro embryo production (IVP) provides an alternative mean to increase the number of offspring from genetically valuable cows. The objective of this study was to investigate the effect of two different cattle breeds on oocyte recovery rate, quality and subsequent embryo development after transvaginal ovum pick up. Transvaginal ultrasound guided (Pie Medical, Netherlands) oocyte collection was performed in 8 nonlactating donor cows (4 Holstein-Frisian and 4 Charolais). Cows were synchronized with PGF2&#61537; and stimulated with pFSH, twice a day during two days (Folltropin&#174; ; , Bioniche, a total dose: 200 mg NIH-FSH-P1). OPU was performed 24 hours after the last FSH injection and procedure was repeated every second week for eight consecutive weeks. The number of aspirated follicles, the number of retrieved oocytes and oocyte recovery rate were recorded. The collected oocytes were morphologicaly evaluated and subsequently submitted to in vitro embryo production. The cleavage rates on Day 2, the total number of morulas (M) and blastocysts (Bl) on Day 7 and the numbers of hatched blastocysts (hBl) on Day 9 were recorded. Significantly more follicles were aspirated from Charolais cows (p<0.05). The same group also yielded higher quality oocytes than the Holstein Fresian cows (p<0.05). No differences in recovery rates, cleavage rates, blastocyst rates and hatched blastocyst rates were observed between two breeds. Although we observed some breed differences related to the number of follicles and oocyte quality, further investigations are necessary to provide more data on breed influences on superovulatory response, oocyte number, quality and developmental competence.

cow; breed; ovum pick up; oocyte recovery; embryo development

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