Browsing by Author "Say, Erkan"

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Effect of embryo quality on pregnancy outcome in recipient cows and heifers
(Hellenic Veterinary Medical Soc, 2020-04-01) Kara, Uğur; Çoban, S.; Say, Erkan; Hızlı, Hatice; Mutlu, H.; Sagırkaya, H.; Ayasan, T.; Coskun, M. A.; Asarkaya, A.; Erten, H. E.; Yilmaz, I.; Yazgan, E.; Erdoğan, I. E.; Erten, Z. M.; Ergül, S.; Sert, F.; Nak, Yavuz; NAK, YAVUZ; Sağırkaya, Hakan; SAĞIRKAYA, HAKAN; Bursa Uludağ Üniversitesi/Veteriner Fakültesi/Doğum ve Jinekoloji Anabilim Dalı.; AAH-5494-2021; AAH-8821-2021
This study was performed to compare the effects of embryo quality on pregnancy outcome in recipient cows and heifers. Embryos obtained from 83 Holstein donors were used in the study. In order to synchronize the recipients, 500 mu g of cloprostenol were administered intramuscularly (i.m.), twice, at an interval of 11 days. In all recipients, one embryo was transferred to the upper 1/3 of the uterine horn ipsilateral to the ovary with the corpus luteum on the 7th day after oestrus onset (day 0). Each recipient received an i.m. injection of 5 mu g of buserelin at the time ofembryo transfer. Pregnancy examinations were performed by ultrasonography on the day 30th post-transfer. A total of 345 (262 grade 1, 64 grade 2 and 19 grade 3) fresh embryos were transferred to 171 recipient cows and 174 recipient heifers. The pregnancy rates of the recipient cows and heifers were 41.52% and 52.29%, respectively (p<0.05).The pregnancy rates achieved with first, second and third quality grade embryos were 45.16%, 25.0% and 12.5% in the cows (p<0.05), and 55.11%, 41.66% and 54.54% in the heifers (p>0.05), respectively. In conclusion, the pregnancy rates was significantly higher in heifers than in cows (p<0.05) and, the embryo quality had a significant impact on recipient pregnancy outcome (p<0.05). The effect of embryo quality on pregnancy was significant in cows (p<0.05), but not significant in heifers (p>0.05).
Embriyo transfer uygulamaları ile repeat breeder ineklerde gebelik oranlarının araştırılması
(Uludağ Üniversitesi, 2018-06-20) Say, Erkan; Sağırkaya, Hakan; Uludağ Üniversitesi/Sağlık Bilimleri Enstitüsü/Dölerme ve Suni Tohumlama Anabilim Dalı.
Bu çalışmanın amacı tekrarlayan tohumlamalara rağmen, gebe kalmayan ve bu nedenle sürüden çıkarılması gereken döl tutmayan (repeat breeder) olarak tanımlanan ineklerde uygulanacak embriyo transferi sonucunda elde edilecek gebelik oranlarının araştırılmasıdır. Ayrıca, taşıyıcı olarak kullanılacak ineklerde korpus luteum kalitesi, embriyo gelişim safhası-kalitesi ve kan progesteron seviyelerinin gebe kalma üzerindeki etkisinin belirlenmesi de hedeflenmiştir. Çalışmada Holstein ırkından yaşları 3-8 arası değişen, rastgele seçilmiş 87 baş inek kullanılmıştır. Döl tutmayan inekler (n=45); en az bir doğum yapmış, seksüel siklusları düzenli olan, genital organlarında klinik bir bozukluk bulunmayan ve anormal bir akıntı göstermeyen, ancak en az üç defa veya daha fazla sayıda suni tohumlama yapılmasına rağmen gebe kalmayan ineklerden seçilmiştir. Kontrol grubunu (n=42) oluşturacak inekler ise, doğum sonrası hiç suni tohumlama işlemine tabi tutulmayan hayvanlardan oluşturulmuştur. Taşıyıcı ineklere transferden 24 gün önce PGF2α uygulaması yapılmıştır. Bu uygulamadan sonra, inekler takibe alınmış ve östrus belirtileri gösteren hayvanlar kayıt altına alınıp taşıyıcı adayı olarak belirlenmiştir. Deneme grubunda transfer yapılan toplam 45 taşıyıcı döl tutmayan inekten 16'sı gebe kalmıştır. Kontrol grubunda ise, 42 taşıyıcı ineğe yapılan embriyo transfer işleminden sonra 21 inek gebe kalmıştır. Yapılan istatistiksel analiz sonucu deneme ve kontrol gruplarında gebelik oranları sırasıyla %35,6 ve %50 olarak belirlenmiştir. İki grup arasında istatistksel fark bulunmuştur (p<0,05). Çalışmada bunun dışında korpus luteum yapısı ile gebe kalma arasındaki ilişki incelenmiş olup, yapılan istatistiksel analizde korpus luteum büyüklüğünün gebe kalma üzerine etkisi olmadığı tespit edilmiştir (p>0,05). Ayrıca embriyo safha ve kaliteleri de değerlendirilmiştir. Buna göre embriyo safha ve kalitesinin gebelik üzerinde önemli bir etkisi olmadığı görülmüştür (p>0,05). Her iki grup içerisinde örneklem gruplar oluşturularak kan progesteron değerlerine bakılmıştır. Kan progesteron seviyesinin de gebelik üzerinde etkisi olmadığı saptanmıştır (p>0,05). Sonuç olarak döl tutmayan inekler için embriyo transferinin bir tedavi yöntemi olarak uygulanabileceği, özellikle yüksek süt verimli ineklerin gebe bırakılmasında kullanılabileceği kanısına varılmıştır. Böylece tercihen üstün özelliklere sahip ineklerin embriyolarının döl tutma problemi yaşayan özellikle yüksek süt verimli ineklere transferi ile bu hayvanların gebe bırakılarak sonraki laktasyondada yüksek süt veriminden yararlanılarak ekonomik fayda sağlanabileceği kanısına varılmıştır. Bunun yanı sıra, taze embriyo transferi için taşıyıcı olarak kullanılacak ineklerde korpus luteum büyüklüğü ile kan progesteron değerinin ve transfer edilen embriyo safha-kalitesinin gebelik oranları üzerinde etkisi olmadığı tespit edilmiştir.
Fertility of Holstein heifers after two doses of PGF2 alpha in 5-day CO-Synch progesterone-based synchronization protocol
(Elsevier, 2016-03-17) Say, Erkan; Çoban, Serdal; Kara, Uğur; White, Stephanie; Kasimanickam, Vanmathy; Kasimanickam, Ramanathan; Nak, Yavuz; Nak, Deniz; Uludağ Üniversitesi/Veteriner Fakültesi/Jinekoloji Anabilim Dalı.; AAH-5494-2021; 8615464000; 9280090000
The objective of the study was to determine the effect of three different PGF2 alpha, (PGF) treatments in the 5-day CO-Synch progesterone-based synchronization protocol on artificial insemination (AI) pregnancy rate (PR) in Holstein heifers in Turkey and the United States. We hypothesized that two doses of PGF administered concurrently or 6 hours apart would result in greater AI pregnancy compared with a single dose of PGF on Day 5 at controlled internal drug release (CIDR) removal. In Turkey, Holstein heifers (n = 450) from one farm in the province of Adana and another farm in the province of Bursa were included. In the US, Holstein heifers (n = 483) from two locations in the state of Idaho were included. Heifers within locations were randomly allocated to one of three protocol groups: 1PGF-received 25 mg IM of dinoprost at CIDR removal; 2Co-PGF-received 50 mg IM of dinoprost at CIDR removal, and 2PGF received 25 mg 1M of dinoprost at CIDR removal and an additional 25 mg IM of dinoprost 6 hours later. All heifers received a CIDR (1.38 g of progesterone) and GnRH (10 mu g IM of Buserelin [Turkey] or gonadorelin hydrochloride [US]) on Day 0. The CIDRs were removed on Day 5, and each heifer was given PGF according to the assigned treatments. On Day 7, each heifer was given another dose of GnRH and concurrently inseminated at 56 hours after CIDR removal. Heifers in both experiments were examined for pregnancy status between 35 and 45 days after AI. Overall, controlling for age, the heifers in the 2PGF group had greater Al-PR (61.7% [192/311]) than heifers in 2Co-PGF (48.2% [149/309]; P < 0.001) or 1PGF (53.7% [168/313]; P < 0.05) groups. No difference was observed between 2Co-PGF and 1PGF groups (P > 0.1). In Turkey, the heifers in the 2PGF group had a greater AI-PR (60% [90/150]) than 2Co-PGF (45.3% (68/150); P < 0.01] group. No difference was observed between 2PGF and 1PGF (55.3% [83/1501) groups (P > 0.1). There was a trend for Al pregnancy between 1PGF and 2Co-PGF groups (P = 0.08). In the United States, the heifers in the 2PGF group had a greater Al-PR (63.4% [102/161]) than the heifers in 2PGF (50.9 [81/159]; P < 0.05) or 1PGF (52.1% [85/163]; P < 0.05) groups. Heifers that were 15- and 16-month old achieved greater Al-PR than 17- and 18-month-old heifers (59.2 [342/578] vs. 47.0% [168/355]; P < 0.01). In conclusion, administration of 2PGF at 6 hours apart on Day 5 at CIDR removal in a 5-day CO-Synch + CIDR protocol resulted in greater Al pregnancy. A greater number of 15 and 16-month-old heifers became pregnant compared with 17- and 18-month-old heifers.
Searching of pregnancy rate in repeat breeder cows by embryo transfer practices
(Galenos Publ House, 2021-01-01) Say, Erkan; Sağırkaya, Hakan; SAĞIRKAYA, HAKAN; Bursa Uludağ Üniversitesi/Veteriner Fakültesi/Döllenme ve Suni Tohumlama Anabilim Dalı; DPO-0081-2022
The aim of this study is to compare the pregnancy rates by applying embryo transfer to the cows which are not pregnant and should be removed from herd as repeat breeder. In this study, 87 randomly selected Holstein cows utilized. The repeat breeder cows (n=45) were selected from at least one giving birth, having regular sexual cycle, missing clinical worsening into genital organ and not displaying an abnormal discharge. On the other hand, it was selected from nonpregnant cows which inseminated artificially at least 3 times or more. Besides, cows that used as the control group (n=42) were selected from the cows without any artificial insemination postnatally. The PGF2 alpha application was performed to all recipient cows which are considered to benefit from as a recipient in control and testing groups just 24 days before the flushing day. After this application, the cows showing estrous symptoms were recorded and determined as candidate recipients. The pregnancy rates were 35.6% and 50% for testing and control groups, respectively and the difference between the groups was significant (P<0,05). As a result, even this difference between the groups it has been concluded that embryo transfer can be used to conceive especially for high-yielding cows as a treatment method for repeat breeder cows. Thereby, embryo transfer from the cows with high superior characteristics to the high milk yielding cows which have infertility problems can economically be beneficial by utilizing the high milk yield in the later lactation without any replacement cost.