Authors: BURCU ÜSTÜNER, SELİM ALÇAY, YAVUZ NAK, ZEKARİYA NUR, DENİZ NAK, BİLGİNER TUNA, GÖZDE ŞİMŞEK, HAKAN SAĞIRKAYA
Abstract: The present study compared superovulation and embryo recovery rates applied repeatedly during breeding and nonbreeding seasons in the same 20 Kivircik sheep. Trials 1 and 3 were performed during the breeding season and the trial 2 was performed in the nonbreeding season. We synchronized the sheep's estrus cycles and induced a superovulatory response with porcine follicle stimulating hormone (pFSH) injections. Natural mating took place 12 h after the last FSH injection. The embryos were collected by laparotomy 7 days after natural mating. There was no significant difference between the number of corpora lutea (CL) counted following the 1st (breeding) and 2nd (nonbreeding) superovulatory treatments (P > 0.05). However, the number of CL in the 3rd (breeding) treatment was dramatically lower than that in the other groups (P < 0.001). Recovery rates showed significant differences among embryo flushing treatments (P < 0.001). The number of morulae + blastocysts and freezable-quality embryos decreased considerably for the 3rd flushing treatment (P < 0.001), while no significant difference was observed between the 1st and 2nd flushing treatments (P > 0.05). In conclusion, our study demonstrated that 2 consecutive in vivo embryo production programs can be successfully applied in Kivircik ewes with suitable superovulation treatments and operation techniques, irrespective of the season.
Keywords: Sheep, superovulation, embryo, FSH
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