58 research outputs found
The effects of different doses of ROCK inhibitor, antifreeze protein III, and boron added to semen extender on semen freezeability of Ankara bucks
In the presented study, the effects of ROCK inhibitor Y-27632, antifreeze protein III, and boron at two different doses were investigated on the spermatological parameters of Ankara buck semen after freeze–thawing. Ejaculates were collected from bucks using an electroejaculator during the breeding season. The ejaculates that showed appropriate characteristics were pooled and used in the dilution and freezing of semen. The extender groups were formed by adding two different doses of three different additives (ROCK inhibitor Y-27632, 5 and 20 µM; antifreeze protein III, 1 and 4 µg/mL; boron, 0.25 and 1 mM) to the control extender. The semen was diluted with the different extenders at 35–37 °C and loaded into straws. Sperm samples frozen in liquid nitrogen vapors, following equilibration, were stored in liquid nitrogen. It was observed that extender supplementation improved post-thaw motility of Ankara buck semen after freeze–thawing. Differences were significant (p 0.05). It was observed that DNA damage was improved by antifreeze protein III at 1 µg/mL (1.23% ± 0.23%) and by boron at all doses (0.25 mM: 1.83% and 1 mM: 1.18%) compared to the control group (3.37%) (p < 0.01), following the thawing process. In the present study, it was determined that some additives added to the extender provided significant improvements in buck spermatozoa motility and DNA damage after thawing
Cryobiology and Cryopreservation of Sperm
Low temperature has been utilized to keep living cells and tissues dormant but potentially alive for cryopreservation and biobanking with great impacts on scientific and biomedical applications. However, there is a critical contradiction between the purpose of the cryopreservation and experimental findings: the cryopreserved cells and tissues can be fatally damaged by the cryopreservation process itself. Contrary to popular belief, the challenge to the life of living cells and tissues during the cryopreservation is not their ability to endure storage at cryogenic temperatures (below −190°C); rather it is the lethality associated with mass and energy transport within an intermediate zone of low temperature (−15 to −130°C) that a cell must traverse twice, once during cooling and once during warming. This chapter will focus on (1) the mechanisms of cryoinjury and cryopretection of human sperm in cryopreservation, and (2) cryopreservation techniques and methods developed based on the understanding of the above mechanisms
Effects of Heat-Stress on Oocyte Number and Quality and In Vitro Embryo Production in Holstein Heifers
Background: This study aimed to determine the effects of environmental temperature on the number and quality of oocytes and embryo production rates obtained by performing ovum pick up (OPU). Heat stress leads to long-term, short-term, visible, and invisible effects in dairy cows. Its effects on reproduction are evident in all stages, from oocyte development to birth. Disturbance in ovarian follicle development, follicular dominance deficiency, anoestrus, polyspermia, embryoniclosses, decreased fetal growth, and abortion are some examples of responses to these effects. The aim of the present study was aimed to determine the effects of ambient temperature on oocyte quality and number and embryo production rates.Materials, Methods & Results: The animal material used in this study comprised 10 Holstein heifers. At the beginning of the study, the heifers were 13-15 months old. OPU was performed at different times of the year, and weather conditions were recorded. Grouping according to ambient temperature was done as < 10°C (group 1), 10-25°C (group 2), and > 25°C (group 3). The veterinary ultrasonography device and a set of compatible intravaginal OPU probe, catheter, and aspiration device were used for OPU application. All antral follicles with diameters of 2-8 mm in the ovaries were aspirated. The aspirated follicle fluids were examined under a stereo microscope, and the cumulus-oocyte complexes (COC) were collected and classified according to their structure. A, B, and C-quality oocytes were included in the in vitro embryo production process. After performing 69 OPUs on random days of the cycle, the number of oocytes per OPU was found to be 8.72, 6.32, and 6.85 in groups 1, 2, and 3, respectively (P < 0.05). The number of viable oocytes per OPU was 6.83, 4.64, and 4.65 in groups 1, 2, and 3, respectively (P < 0.05). The statistical difference between the first group and the other groups was significant for cleavage and blastocyst counts (P < 0.05).Discussion: All the negative effects of heat stress on animals resulted from the increased body temperature. Reproductive performance is adversely affected by high temperatures and humidity during periods of high ambient temperatures. Metabolic heat is released, and the heat load increases due to the metabolism of nutrients in cattle. Internal body temperature is regulated via the dissipation of metabolic heat to the environment. The amount of heat dissipated via conduction andconvection depends on the unit body weight, surface area, skin and coat color, difference in temperature gradient of the animal and ambient temperature, and humidity. In the present study, it was determined that the blastocyst development rates of the oocytes obtained in the warm season (>25°C [group 3]) were lower than those of the other groups. It was concluded that this may be because the oocytes developed under chronic heat stress in the animals, and several cycles were required to enhance oocyte quality and developmental potential. Additional studies are needed to investigate the response of oocytes obtained with OPU to heat stress during embryonic developmental stages and to determine the sensitivity and effects of embryonic tissue damage according to developmental stages. Based on the results of the present study, it was concludedthat performing OPU and in vitro embryo production (IVEP) when the ambient temperature is close to the thermoneutral limits may increase the blastocyst development rates.
Keywords: blastocyst, heat stress, heifer, in vitro embryo production, oocyte quality, ovum pick-up
The effects of different egg yolk concentrations used with soy bean lecithin-based extender on semen quality to freeze bull semen
Özet Sarıözkan S, Tuncer PB, Bucak MN, Büyükleblebici S, Kinet H, Bilgen A. Boğa spermasının dondurulmasında soya lesitin temelli sulandırıcı ile birlikte kullanılan farklı yumurta sarısı konsantrasyonlarının sperma kalitesi üzerine etkileri. Eurasian J Vet Sci, 26, 1, 45-49 Amaç: Boğa spermasını dondurmak için soya lesitin temelli sulandırıcıya (Bioxcell ® ) %5 ve 10 konsantrasyonlarında santrifüj edilmiş yumurta sarısı (SYS) katıldı ve bunların çözüm sonu sperm motilite, morfolojik anormallikler ve membran bütünlüğü üzerindeki sinerjistik etkileri değerlendirildi. Gereç ve Yöntem: Her bir Simental boğadan alınan ejakulatlar (n=12) üç eşit miktara ayrıldı ve sırasıyla %5 (B5), %10 (B10) SYS eklenmiş ve hiç SYS (B0) içerme-yen soya lesitin temelli sulandırıcı ile sulandırıldı. Ardın-dan standart protokollere göre donduruldu ve çözdürül-dü. Spermatozoa kryocanlılığı, in vitro çözüm sonu motilite (CASA), akrozomal ve diğer anormallikler ve plasma membran bütünlüğü (HOST) yönünden değerlendirildi. Bulgular: Simental boğalarda, dondurma ve çözdürme sonrası B5 ile sulandırılan grupta, diğer sulandırıcılar-la sulandırılan gruplardan önemli derecede daha yüksek CASA motilite ve CASA progresif motilite oranı elde edilmiştir (p<0.001). Gruplar arasında, VAP, VCL ve ALH yö-nünden önemli bir farklılık bulunmamıştır (p>0.05). En yüksek VSL (p<0.01) ve LIN değeri (p<0.001) B10 grubundan elde edilmiştir. Membran bütünlüğü oranı, B5 grubunda, diğer gruplara göre önemli derecede yüksek bulunmuştur (p<0.001). Öneri: Soya lesitinle kombine olarak sulandırıcıya %5 SYS eklenmesi boğa spermasının dondurulabilirliğini önemli derecede artırmıştır. Abstract Sariozkan S, Tuncer PB, Bucak MN, Buyukleblebici S, Kinet H, Bilgen A. The effects of different egg yolk concentrations used with soy lecithin-based extender on semen tuality to freeze bull semen. Eurasian J Vet Sci, 26, 1, 45-49 Aim: The centrifuged egg yolk (CEY) was added at concentrations of 0.5 or 10% to a defined soy lecithin-based extender (Bioxcell ® ) used to freeze bull semen and their synergistic effects on post-thaw sperm motility, morphological abnormalities and membrane integrity assessed. Materials and Methods: Ejaculates obtained from each Simmental bull (n:12) divided in three equal aliquots and diluted in CEY 5% (B5), 10% (B10) supplemented, and without any CEY (B0) in soy bean lecithin -based extender, respectively. Thereafter, they were frozen and thawed following a standart protocol. Sperm cryosurvival was evaluated in vitro by microscopic assessments of post-thaw sperm motility (by means of the CASA), acrosomal and other abnormalities (head, mid-pieces, and tail) and plasma membrane integrity (evaluated by HOST). Results: In Simmental bulls, semen extended with B5 had significantly higher CASA motility and CASA progressive motility than those extended with the rest of extenders after freezing and thawing (p<0.001). There was no significant difference in VAP, VCL, and ALH among the three groups (p>0.05). For VSL (p<0.01) and LIN (p< 0.001), the highest values were obtained from B10 group. The highest percentages of acrosomal and other abnormalities were found in semen diluted in B10 (p<0.001). In the group frozen B5, the percentage of membrane integrity was significantly higher than that of the other groups (p<0.001). Conclusion: The use of CEY 5% in combination with soy bean lecithin significantly improved bull semen freezability
Introductory Chapter: Reproductive Strategies and Biotechnologies in Terrestrial and Aquatic Animals
Çiftlik Hayvanlarında Embriyo Transferi Uygulamalar
Genetik özellikler bakımından daha verimli ve daha güçlü ırklar yetiştirmek amacıyla embriyo transferi uygulamaları ülkemizde ve dünyada yaygın bir biçimde kullanılmaktadır. Başarılıbir embriyo transferi uygulaması yapabilmek için transfer işleminin her bir basamağında dikkatliçalışmak ve gerek manipülasyonlar gerekse kültür esnasında oosit ve embriyo kaybını en aza indirmek gerekmektedir. Fiziksel manipülasyonlardan kaynaklanan embriyo kayıplarının yanı sıra birdiğer önemli faktör de embriyoların kültür medyumlarında kültüre edilmesi ve dondurulması esnasında meydana gelen kayıplardır. Bu kayıpların temel sebebi ise optimum kültür ortamlarında daortaya çıkabilen ve dondurma esnasında asıl hasara neden olan reaktif oksijen türlerinin (ROS) oluşumudur. ROS hücrelerin membranında ve etki ettiği tüm dokularda hasara neden olmaktadır. Buderlemede embriyo transferi uygulamalarında ortaya çıkan ROS un etki mekanizması ve ROS zararına karşı savunma sistemi olarak antioksidan kullanımından bahsedilmiştir.</p
Prevention of embryonic death using different hormonal treatments in ewes
The purpose of this study was to evaluate different treatment protocols to prevent embryonic death in ewes. A total of 180 Akkaraman crossbred ewes and 10 healthy rams were used as material. The ewes were divided into 3 equal groups, with each of the 3 groups then separated into 3 subgroups. Ewes in estrus, determined with teaser rams, were exposed to mating. Three different treatment protocols of gonadotropin-releasing hormone (GnRH) analog (buserelin, intramuscularly) at a dose of 20 &#956;g, vaginal sponges containing 30 mg fluorogestone acetate (FGA), and saline at a dose of 1 mL (control, intramuscularly) were applied on days 4, 12, and 16, respectively, for each subgroup after mating. No significant differences were observed in the pregnancy or multiple birth rates among any of the treatment groups. In the groups treated on days 4 and 12 after mating, the hormonal treatments gave lower rates of embryonic death compared to the control group (P < 0.05). In conclusion, the application of GnRH or FGA on days 4 and 12 after mating was found to be effective in preventing embryonic death in ewes.The purpose of this study was to evaluate different treatment protocols to prevent embryonic death in ewes. A total of 180 Akkaraman crossbred ewes and 10 healthy rams were used as material. The ewes were divided into 3 equal groups, with each of the 3 groups then separated into 3 subgroups. Ewes in estrus, determined with teaser rams, were exposed to mating. Three different treatment protocols of gonadotropin-releasing hormone (GnRH) analog (buserelin, intramuscularly) at a dose of 20 &#956;g, vaginal sponges containing 30 mg fluorogestone acetate (FGA), and saline at a dose of 1 mL (control, intramuscularly) were applied on days 4, 12, and 16, respectively, for each subgroup after mating. No significant differences were observed in the pregnancy or multiple birth rates among any of the treatment groups. In the groups treated on days 4 and 12 after mating, the hormonal treatments gave lower rates of embryonic death compared to the control group (P < 0.05). In conclusion, the application of GnRH or FGA on days 4 and 12 after mating was found to be effective in preventing embryonic death in ewes
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