engleski

Comparison of different synchronization protocols on OPU/IVF results in FSH stimulated Simmental heifers

The success of ovum pick-up (OPU) and in vitro embryo production considerably depends on the number and the quality of retrieved oocytes per session and also on the culture conditions. The aim of the study was to compare the effect of different synchronization protocols on oocyte retrieval and blastocyst production in vitro in FSH stimulated Simmental heifers. Twenty-eight normal cyclic Simmental heifers, aged between 14 and 20 months were selected based on transrectal palpation for oocyte donors. They were randomly allocated to one of three synchronization groups. In the 1st (PGFx2) group heifers (n=10) were synchronized with two prostaglandin F2&#61537; injections at 11-day interval. In the 2nd (PGF + DFR) group heifers (n=8) were synchronized with two prostaglandin F2&#61537; treatments at 11-day interval and dominant follicles (>8 mm) were aspirated (DFR: dominant follicle removal) 36 hours before FSH stimulation. In the 3rd (Crestar + DFR) group (n=10) a norgestomet ear implant without the prescribed oestrogen injection (Crestar&#174; ; , Intervet, Begium) was inserted for 10 days. The implants were removed and dominant follicles were aspirated 36 hours before FSH stimulation. The stimulation with pFSH (Folltropin&#174; ; -V, Vetrepharm Inc., London, Canada) was the same fir all three groups and it was administered twice a day, during two days beginning on the day 9 or 10 of the estrous cycle. The total amount of pFSH administered was 200 mg NIH-FSH-P1 in 4 equivalent doses. OPU was performed 48 hours after the last FSH injection. Only good quality oocytes were matured, fertilized and cultured in vitro in SOFaaBSA till the Day 9. Cultured embryos were evaluated morphologically according to IETS standards. The cleavage rates on Day 2, the total number of morulas (M) and blastocysts (Bl) on Day 7 and the number of hatched blastocysts (hBl) on Day 9 were recorded. The results were statistically analyzed with ANOVA (StatSoft, Statistic, version 7.1.) and with Tukey, s tests post-hoc analysis.The results are presented in the table. Table: Effect of different synchronization protocols on oocyte retrieval and IVF/IVC results in FSH stimulated Simmental heifers (mean&#177; ; SD) Synchronization protocol Follicles aspirated Oocytes retrieved Oocytes in IVP Cleavage (%) M/Bl (%) hBL (%) PGFx2 group (n=10) 14.5 (&#177; ; 3.9)a 10.3 (&#177; ; 5.2)b 9.5 (&#177; ; 5.6)a 86.8 (&#177; ; 1.8)a 41.1 (&#177; ; 2, 2) a 22.4 (&#177; ; 1.8) a PGF + DFR group (n=8) 13.3 (&#177; ; 3.9) a 7.6 (&#177; ; 4.0) a 6.9 (&#177; ; 4.5) ab 91.0 (&#177; ; 1.3) a 28.9 (&#177; ; 2.2) b 12.4 (&#177; ; 1.4) b Crestar + DFR group (n=10) 13.1 (&#177; ; 4.1) a 9.1 (&#177; ; 4.1) ab 5.9 (&#177; ; 3.6) b 94.7 (&#177; ; 0.8) a 43.6 (&#177; ; 2.0)a 23.2 (&#177; ; 1.5) a Values with different superscripts within the same columns differ significantly (P<0.05 ; ANOVA) In conclusion, the results of this study demonstrate that synchronization protocol did not affect the number of follicles following superstimulation but it did affect the number and the quality of the retrieved oocytes and the blastocyst yield.

heifer; ovum pick up; synchronization; IVF

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