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Öğe The comparing of homogenization methods for oxidative and antioxidative analyses of sperm(Scientific Technical Research Council Turkey-Tubitak, 2019) Varisli, Omer; Akyol, NumanPretreatment of sperm for oxidative and antioxidative analysis has been shown to be different in studies. These differences can affect the result of analyses. The aim of this study was to compare the analyses of sperm homogenization methods. The semen of four rams were used in the study. Pretreatment procedures included the rotary, bead, and ultrasonic homogenization methods. Oxidative and antioxidative status of sperm samples was assessed by measuring serum lipid hydroperoxide, total oxidant status, free sulfhydryl groups (SH total thiol), ceruloplasmin, and total antioxidant capacity levels. As a result, the homogenization methods before oxidative and antioxidative status analyses significantly affected the result (P < 0.05), and the ultrasonic homogenization method was the most effective. It is recommended to use the ultrasonic homogenization as a pretreatment method to determine the oxidative and antioxidative status analyses in sperm.Öğe Comparison of Flow Cytometric Analysis and Eosin-Nigrosin Staining Methods for Determining some Morphological Characteristics of Bull Epididymal Spermatozoa(Kafkas Univ, Veteriner Fakultesi Dergisi, 2015) Akyol, Numan; Azkur, Ahmet Kursat; Ekici, HusamettinThe aim of this study is to investigate necrosis and apoptosis in epididymal bull spermatozoa before freezing and after thawing using the flow cytometric method and to compare this with eosin-nigrosin dyeing, which is the conventional method used in assessing of spermatozoa. The testicles from fourteen bulls at local slaughterhouse were used for this study. The proportions of live spermatozoa, total apoptotic, necrotic and early necrotic spermatozoa levels were observed via flow cytometry. Annexin V/ PI fluoruscence dyeing was used to investigate the proprotions of apoptotic, necrotic, early necrotic and live spermatozoa for flow cytometry. The proportion of dead spermatozoa and protoplasmic droplets were determined using the eosin-nigrosin conventional dyeing method in fresh and frozen-thawed spermatozoa. The average dead spermatozoa count with flow cytometry was less than with the eosin-nigrosin method (P < 0.05). Some morphological characteristics such as protoplasmic droplets could be determined with the eosin-nigrosin method; however, sperm subpopulations entering the death process (apoptotic, necrotic and early necrotic) could be defined clearly only with the flow cytometric method. As a result, combination of eosin-nigrosin dyeing method and flow cytometric analysis of sperm morphological evaluation could give better results of bull epididymal semen in comparison to eosin-nigrosin dyeing method alone.Öğe Effects of different extenders and additives on liquid storage of Awassi ram semen(Scientific Technical Research Council Turkey-Tubitak, 2018) Varisli, Omer; Taskin, Abdullah; Akyol, NumanThe aim of this study was to evaluate the effects of different extenders and additives on ram semen during liquid storage and to demonstrate the role of oxidative stress parameters on this process. In the present study, ejaculates taken by artificial vagina twice a week from 4 rams during the breeding season were used. They were mixed and used if motility and viability were above 70% and there was a 95% intact acrosome. The semen specimens were diluted by Tris-citrate-glucose (TRIS), Tris-TES (TEST), HEPES-buffered Tyrode lactate (TL-HEPES), and Dulbecco's phosphate-buffered saline (PBS) extenders supplemented with different additives [centrifuged egg yolk, Equex-STM, bovine serum albumin (BSA), and ethylenediaminetetraacetic acid (EDTA)]. The specimens were stored at 4 degrees C for up to 96 h and evaluated for motility, membrane integrity, acrosome integrity, mitochondrial membrane potential (MMP), and oxidative stress parameters. At the end of the 96-h storage, the highest sperm motility was 64.2 +/- 3.7% (P < 0.05) and significant loss of sperm motility and membrane integrity were not detected in extender TEST-3, but the MMP rate significantly declined. Acrosome integrity was not affected by storage time or extender types. BSA and EDTA decreased lipid peroxidation (LPO) and total oxidant status (TOS), but did not positively affect motility or membrane integrity. As a result, TRIS, TEST, and TE-FIEPES-3 were observed to provide better protection for ram semen during liquid storage at 4 degrees C than other extenders. The role of oxidative stress and MMP are considerable in liquid storage.Öğe Effects Of Long-Term Storage On Some Spermatological Parameters In Cryopreserved Bull Semen(Cryo Letters, 2018) Akyol, Numan; Varisli, Omer; Kizil, Sedat HamdiBACKGROUND: The effect of the long-term storage in liquid nitrogen on semen quality has not be reported. OBJECTIVE: The study measured the spermatological parameters of bull sperm after the long-term and short-term storage. MATERIALS AND METHODS: Vintage semen (obtained from 5 Brown Swiss bulls and frozen 30 years ago) and newly frozen semen collected from 5 bulls of the same breed and prepared at the International Center for Livestock Research and Training were used. For each bull, 10 straws (0.25 ml) were thawed and pooled. Sperm samples were analyzed by flow cytometry, computer assisted sperm analysis, and total oxidant-antioxidant levels were also tested. RESULTS: The ratios of necrotic (P < 0.001) and apoptotic (P = 0.006) spermatozoa, and the ratios of total antioxidant status (TAS) and total oxidant status (TOS) were significantly higher (P < 0.001) in long-term frozen spermatozoa. However, the early necrotic ratios (P < 0.001), velocity average pathway (VAP) (P = 0.008) and velocity curvi linear (VCL) (P = 0.01) values of long-term frozen semen were lower compared with short-term frozen semen. While necrotic and apoptotic spermatozoa ratios and total oxidant level were higher, VAPNCL ratios were lower in long-term frozen sperms compared to short-term frozen semen. CONCLUSION: Long-term storage of sperm may adversely affect the spermatological and oxidative parameters of Brown Swiss bull spermatozoa.Öğe Farklı dönemlerdeki in vivo üretilmiş sığır embriyolarında cinsiyetin dağılımının belirlenmesi ve cinsiyetin bu dağılıma etkisinin araştırılması(2013) Karaşahin, Tahir; Satılmış, Muharrem; Kızıl, Sedat Hamdi; Akyol, NumanBu çalışmanın konusu, farklı dönemlerdeki in vivo sığır embriyolarının cinsiyetlerinin non elektroforetik PCR yön- temi ile tespit edilerek, cinsiyet dağılımının ve bu dağılımın arasındaki farkların cinsiyetten etkilenip etkilenmediğinin belirlenmesidir. Cinsiyet tayini amacıyla yedi günlük toplam 65 adet in vivo üretilmiş embriyo kullanıldı. Embriyo elde etmek için rutin süperovulasyon yöntemleri kullanıldı. Tohumlamalardan yedi gün sonra cerrahi olmayan yöntemle uterus yıkaması yapılarak embriyolar toplandı. Elde edilen embriyolar kalite değerlendirmesinin ardından cinsiyetleri tespit edildi. Embriyoların trophektoderm kısmından mikro manipülatöre bağlı mikro bıçak ile %10-30 oranında bir par- ça kesilerek biyopsi materyali alındı. Embriyodan biyopsi alma işlemi %20 FCS içeren D-PBS solüsyonu içerisinde yapıldı. Alınan biyopsi parçaları, lizis ve denaturasyon işlemleri amacıyla PCR cihazına yerleştirildi. Lizisi takiben DNA amplifikasyon işlemi 35 döngü olarak gerçekleştirildi. PCR cihazından çıkarılan tüpler, 302-312 nm dalga boyunda ışık veren UV lamba altında incelendi. Pembe renk veren embriyo “erkek embriyo” olarak belirlendi. Cinsiyet tayini yapılan embriyolardan kompakt morula aşamasında olan 30 embriyodan 14’ünün erkek (%46.7; 14/30), 16’sının dişi (%53.3; 16/30) cinsiyette; blastosist aşamasındaki 35 embriyodan 21’inin erkek (%60.0; 21/35), 14’ünün dişi (%40.0; 14/35) cinsiyete sahip olduğu tespit edildi. Blastosist aşamasındaki erkeklerin oranının (%60.0) morula aşamasına (%46.7) göre daha yüksek bulunmasına rağmen aralarındaki farklılık istatistik önemde bulunmamıştır (P0.05).Öğe Investigation of Bull Effect on in vitro Embryo Production(Kafkas Univ, Veteriner Fakultesi Dergisi, 2014) Akyol, Numan; Kizil, Sedat Hamdi; Satilmis, Muharrem; Karasahin, TahirThe aim of the study was to show whether there were some differences among 9 Holstein bulls and within their replications on their ability of in vitro fertilization for in vitro embryo production as cleavage and coming into the blastocyst stage. Semen collected and frozen from nine Holstein bulls with satisfactory in vivo fertilization capabilities for artificial insemination was used for in vitro fertilization. Direct washing method by Brackett and Oliphant medium and 5 or 6 h incubation period were used for in vitro fertilization. Charles Rosenkrans medium was used for in vitro embryo culture. An atmosphere with a higher than 95% relative humidity, 39 degrees C, 5% CO2 and was used for all in vitro embryo production processes. Totally 2519 A and B quality oocytes were treated for in vitro embryo production. As a result statistically significant (P<0.05) variation was found for cleavage and blastocyst development among bulls. However there was no significant difference (P>0.05) between the replications for each bull as cleavage and coming into blastocyst stage. The results showed varied capabilities of bulls for in vitro fertilization and embryo production and male factor can affect success of in vitro embryo production.Öğe Investigation of conception rates achieved with the transfer of sexed and unsexed bovine embryos(Scientific Technical Research Council Turkey-Tubitak, 2014) Karasahin, Tahir; Akyol, Numan; Satilmis, Muharrem; Kizil, Sedat Hamdi; Bucak, Mustafa Numan; Coyan, KenanThe objective of this study was to investigate the conception rates achieved with the transfer of in-vivo derived sexed and unsexed Holstein bovine embryos to appropriate recipients and to determine the accuracy of nonelectrophoretic PCR sexing. Seven-day-old embryos were derived in vivo by the nonsurgical flushing of the uterus. Before being vitrified and frozen some of the embryos obtained were sexed, while others were not sexed and were maintained as the control group. After thawing, the sexed and unsexed embryos were transferred to 23 and 21 bovine recipients, respectively. The conception rates achieved with the transfer of the sexed and unsexed embryos were 30.4% (7/23) and 42.9% (9/21), respectively. The difference between conception rates achieved in the 2 groups was not statistically significant (P > 0.05). For the sexed embryos the conception rates achieved with the transfer of male and female embryos were 27.2% (3/11) and 33.3% (4/12), respectively The accuracy of embryo sexing with nonelectrophoretic PCR was 66.6% for male embryos and 100% for female embryos postdelivery. The mean rate of accuracy determined for embryo sexing at the end of the study was 83.33%.Öğe Investigation of the Effects of Storage Period for Frozen Bull Semen on In Vitro Embryo Production(Kafkas Univ, Veteriner Fakultesi Dergisi, 2019) Akyol, Numan; Ertem, Talha Burak; Varisli, OmerThe aim of this study was to investigate some spermatological parameters of frozen Brown Swiss bull semen 32 years ago by flow cytometry and to determine how storage time in liquid nitrogen affects in vitro embryo production ratios. For this purpose, early necrotic, necrotic, viable and apoptotic spermatozoa concentrations were analyzed using the Flow Cytometry and then the in vitro fertilization abilities of these sperms were investigated. AnnexinV/PI-FITC (R) was used to determine the apoptotic changes with flow cytometric analysis. Oocytes were obtained from slaughtered cows in a local abattoir. Brown Swiss semen, frozen in the last two years, were used for the control group. Early necrotic spermatozoa levels in semen frozen 32 years ago were lower but necrotic spermatozoa levels were higher than in the control group, but the opposite result was encountered in the control group (P<0.01) according to flow cytometry findings. The cleavage ratio in vintage spermatozoa was found to be lower than in the control group (P<0.0z), the blastocyst ratio was also lower than in the control group (P<0.01). As a result, it was observed that some spermatological parameters can be changed negatively and it can be said that a long storage period may lower the fertility capabilities of Brown Swiss bull semen.Öğe The results of consecutive superovulations in cows by induction with various exogenous progesterone routes(Scientific Technical Research Council Turkey-Tubitak, 2014) Akyol, Numan; Kizil, Sedat Hamdi; Satilmis, Muharrem; Karasahin, Tahir; Erat, SerkanThe aim of this study was to determine the possibility of yielding more transferable embryos from cows superovulated with/without exogenous progesterone (ear implant and intravaginal device). Two experiments were conducted in Holstein Friesian cows to evaluate the effect of exogenous progesterone on the yield of corpus luteum (CL), total embryo and ova, and transferable embryos before superovulation. A superovulation program using 2 different progesterone resources was applied (G1 = intravaginal device, G2 = ear implant). Superovulation and uterus irrigations were done at 28-day intervals in the treatment groups. Cows in the control group were superovulated at 60-day intervals without application of exogenous progesterone. The mean numbers of CLs and transferable embryos for the G1, G2, and control groups were, respectively 4.82 +/- 0.29, 6.71 +/- 0.29, and 7.81 +/- 0.31 for CLs and 0.86 +/- 0.35, 3.50 +/- 0.35, and 1.53 +/- 0.39 for transferable embryos. It was shown that exogenous manipulation of the estrus cycle by progesterone could be applied without superovulation intervals in Holstein cows. It may also be postulated that the ear implant was more effective than the intravaginal device as a progesterone source in the superovulation program.Öğe Süt Sığırcılığında Üreme Verimini Etkileyen Faktörler(2018) Varışlı, Ömer; Akyol, NumanÜreme ve süt verimi sığırcılığının en önemli parametreleridir. Süt sığırcılığının ana hedefini bir cümle içerisindedeğerlendirecek olursak, maksimum süt üretimi ve yılda bir yavru elde etmek olarak niteleyebiliriz. Süt sığırcılığında1950’li yıllardan itibaren yoğun seleksiyon ve bakım-besleme şartlarının iyileştirilmesi ile laktasyon başına süt üretiminde olağan üstü seviyelere ulaşılmıştır. Ancak süt verimine bağlı olarak üreme veriminde ciddi problemler yaşanmayabaşlanmıştır. Günümüz süt sığırcılığında yeni söylem yeterli süt üretimi, yüksek üreme performansı olmaya başlamıştır.Bunda şüphesiz süt üretimindeki artışın doğal sınırlara ulaşması ve tek başına yüksek süt üretiminin karlılığa yeterligelmemesidir.Süt sığırcılığı büyük ve dinamik bir sektör olup araştırma ve geliştirme faaliyetlerinin yoğun olduğu sektördür. Sütsığırcılığının gelişmiş olduğu ülkelerde süt verimi üzerindeki çalışmalar yavaş yavaş üreme etkinliği, süt kalitesi vegenomik seleksiyon gibi konulara kaymaktadır. Ancak Türkiye de durum biraz farklıdır. Gerek suni tohumlama ve gerekse damızlık ithalatı ile gen kaynakları iyileştirme çalışmaları yoğun biçimde devam etse de, modern çiftlikler dışındaistenen laktasyon başına süt üretim düzeyine ulaşılamamış olması hedefimizin hala yüksek süt verimi olarak kalmasınaneden olmaktadır. Türkiye’de kültür ırkı sığır varlığı %50 seviyesinde olup, popülasyonun diğer kısmı genetik olarakiyileştirme ve saflaştırmaya ihtiyaç duymaktadır. Bu sebeple Türkiye’deki üreme parametreleri, çiftlik yapısı, bölge vesığır ırklarına göre kategorize edilip değerlendirilmesi gerekmektedir. Yüksek süt verimine bağlı üreme sorunları şimdilik ülkemizde modern çiftliklerde gözlenmektedir. Ülkemizde üreme sorunlarına neden olan etkenleri; çiftlik yönetimizafiyeti, beslenme hataları, barındırma olanaklarının uygun olmaması, bulaşıcı hastalıklar, yetersiz östrus tespiti, zamanında yapılamayan suni tohumlama, gereksiz ve aşırı hormon kullanımı şeklinde sıralanabilir.Öğe Yerli Kara Düvelerde Farklı Süperovulasyon Protokolleri ile Elde Edilen Cevapların Araştırılması(2017) Satılmış, Muharrem; Akyol, Numan; Kızıl, Sedat Hamdi; Karaşahin, TahirSunulan çalışmanın amacı, süperovulasyon uygulamalarına yanıtı düşük olan Yerli Kara düvelerde, farklı FSH protokolleri ile oluşturulan uygulamaların süperovulasyon etkinliğine yönelik sonuçlarının incelenmesidir. Çalışmada kullanılan 24 baş Yerli Kara düve, rastgele seçilerek dört gruba ayrılmış ve dört farklı süperovulasyon protokolü gerçekleştirilmiştir. Çalışma sonunda, tespit edilen korpus luteum (CL) sayıları üzerine farklı superovulasyon protokollerinin etkinliği görülmemiştir (P>0.05). Eksojen progesteron uygulanmamış grupta (G1), fertilize olmamış oosit (UFO) oranları diğerlerine göre daha yüksek (%43.8) bulunmuştur (P<0.01). Dördüncü grupta (G4) ise diğer gruplara göre daha yüksek oranda embriyo (%72.7) elde edilmiştir (P<0.001). Sonuç olarak Yerli Kara düvelerde uygulanan farklı süperovulasyon protokollerine rağmen yeterli düzeyde cevap gelişmediği gözlenmiştir
