engleski

Comparison of different synchronization treatments in donor heifers for embryo production in vitro

The aim of the study was to compare the effect of different synchronization protocols on oocyte retrieval and blastocyst production in vitro. Twelve Simmental heifers were randomly allocated to one of three synchronization groups. In the 1st group heifers were synchronized with two PGF2α injections in 11-days interval. In the 2nd group heifers were synchronized the same way and dominant follicles (DF) were removed 36 hours before pFSH stimulation. In the 3rd group a progestin ear implant was inserted for 10 days and DF were aspirated 36 hours before pFSH stimulation. The same stimulation protocol with pFSH, starting on Day 9/10 of cycle, was used in all treatment groups. Ovum pick-up (OPU) was performed 48 hours after the last pFSH injection. The number of aspirated follicles, number and quality of retrieved oocytes were recorded. Oocytes were matured, fertilized and cultured in vitro in SOFaaBSA until Day 9. The mean DF diameter and the mean number of expanded oocytes showed a tendency towards signififi cance (0.05 ≤ P ≤ 0.10) in the progestin treatment group. No signififi cant differences between treatment groups were observed in terms of cleavage rate on Day 2, morula/blastocyst rate on Day 7 and hatched blastocysts rate on Day 9. The results indicated that progestin treatment did not prevent the establishment of follicular dominance on the ovaries of heifers. Furthermore, the synchronization protocol did not affect the number of follicles and the recovered oocytes, or the number of in vitro produced embryos.

heifer; synchronization; oocyte; in vitro culture

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