Person: DOĞAN, İBRAHİM
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DOĞAN
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İBRAHİM
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Publication Comparison and assessment of ovarian follicular dynamics during the breeding and non-breeding season in saanen goats(B W K Publishing Solutions & Verlag, 2020-01-01) Dogan, İbrahim; DOĞAN, İBRAHİM; Toker, Mehmed Berk; TOKER, MEHMED BERK; Alcay, Selim; ALÇAY, SELİM; Küçüksen, D. Udum; Veteriner Fakültesi; Biyokimya Bölümü; 0000-0003-1976-1814; A-2794-2014; R-8366-2018We describe and compare the ovarian follicular dynamics and plasma progesterone concentrations in nulliparous Saanen does during the breeding and non-breeding seasons. Does were monitored daily using transrectal ovarian ultrasonography for a full oestrous cycle in the breeding (n = 19) and a 21-day period in the non-breeding season (n = 20). At two-day intervals, blood samples were taken to determine plasma progesterone by ELISA. The pattern of follicular growth was characterised by four and five follicular waves in both seasons. Although the number of follicular waves was similar in the two seasons, the number of codominant follicles (p=0.027), the diameter of the largest follicle of waves 1 (p=0.036) and 4 (p=0.031), the duration of waves 3 (p=0.029) and 4 (p=0.034), the diameter of the largest follicle (p=0.042), the sums of the durations of all waves (p=0.037), the interwave interval (p=0.026) and the follicle growth rate (p=0.044) were higher in the breeding than in the non-breeding season. In addition, the numbers of small, medium and large follicles and the total number of all follicles of all waves differed between the seasons (p=0.037). In the breeding season, we found significant differences between the waves in the diameter of the largest follicles (p=0.042) and the duration of the waves (p=0.037); in the non-breeding season, no significant differences were found. Ovulatory follicles were most common in the fifth follicle wave. In the breeding season, the mean inter-oestrus and inter-ovulatory intervals and the numbers of ovulations after a synchronized oestrus with PGF2a were 21.47 +/- 0.19 days, 20.47 +/- 0.19 days and 1.84 +/- 0.86. The results indicate that follicular growth in Saanen goats during the breeding and non-breeding season is characterised by a wave-like pattern that differs between seasons.Publication Biochemical investigation of blood plasma during estrus and diestrus in repeat breeder cows(Indian Veterinary Journal, 2004-11-01) Doğan, İbrahim; Çetin, Melike; DOĞAN, İBRAHİM; Çetin, Melike; Veteriner Fakültesi; Biyokimya Bölümü; 0000-0003-1976-1814; R-8366-2018; CIO-6717-2022Repeat breeder syndrome is considered as one of the most important causes of infertility in dairy cattle. Deficiencies of various blood biochemical constituents are the major causes for repeat breeder syndrome (Dutta et al., 1991). This study was carried out to examine some plasma biochemical constituents on day 0 (estrus) and 10 (diestrus) of the estrous cycle in repeat breeder cows.Publication Concentration of trace elements in semen and relation to semen characteristics in Arabian stallions(Indian Veterinary Journal, 2008-11-01) Doğan, İbrahim; Oruç, Hasan Hüseyin; Nur, Zekariya; Başkaya, Ruhtan; DOĞAN, İBRAHİM; ORUÇ, HASAN HÜSEYİN; NUR, ZEKARİYA; Başkaya, Ruhtan; Veteriner Fakültesi; Üreme ve Suni Tohumlama Bölümü; 0000-0003-1976-1814; 0000-0002-1438-221X; AAI-2212-2021; R-8366-2018; AAH-2635-2021; CDX-4593-2022Environmental pollutants may influence male reproductive function. Heavy metals such as lead and cadmium are abundant environmental toxicants. The purpose of this study was to determine copper, iron, lead, zinc and cadmium concentration in the semen of Arabian stallions during breeding season, and to find correlation of these elements with conventional semen parameters.Publication Ovarian follicle dynamics and hormonal changes during early pregnancy in saanen goats(Czech Academy Agricultural Sciences, 2020-01-01) Doğan, İbrahim; Toker, Mehmed Berk; Alcay, Selim; Küçükşen, Duygu Udum; DOĞAN, İBRAHİM; TOKER, MEHMED BERK; ALÇAY, SELİM; UDUM, DUYGU; 0000-0003-1976-1814; 0000-0003-4033-9749; A-2794-2014; R-8366-2018; CBC-7350-2022; FGX-3813-2022This study is aimed at describing the ovarian follicular dynamics, corpora lutea and their hormonal control during early pregnancy in Saanen goats. The ovaries of pregnant goats (n = 10) were monitored daily for follicles (>= 2 mm) and corpora lutea by transrectal ultrasound over the 35 days after mating. Blood samples were collected by jugular venipuncture at the time of ultrasonography and were analysed for the concentrations of oestradiol (E-2) and progesterone (P-4), inhibin, FSH (follicle-stimulating hormone) and LH (luteinizing hormone). The pattern of follicular growth was characterised by five (n = 2; 20 %), six (n = 5; 50 %) and seven (n = 3; 30 %) follicular waves during early pregnancy. The first corpora lutea (size 6.8 +/- 0.4 mm, mean + SEM) were detected at 5.0 +/- 0.3 days after the mating with a maximum diameter (12.2 +/- 0.3 mm) observed on day 24.0 +/- 1.1 of pregnancy. The dominant follicle diameter of waves 1 and 4, and the duration of waves 1-4 and 7 were maximal during the early pregnancy period (P < 0.05). In addition, the inter-wave interval of the 5 waves was significantly (P < 0.05) longer compared to the six and seven inter-wave intervals (7.0 +/- 0.1, 5.8 +/- 0.1 and 5.0 +/- 0.2 days, respectively). Although the number of small and medium-sized follicles did not differ with the days post-breeding, the number of large-sized follicles in the same period significantly decreased between 16 and 26 days and was negatively correlated with the period of pregnancy (P < 0.05). The plasma LH and E-2 concentrations were negatively correlated with the P-4 concentration. The inhibin concentrations were negatively correlated with FSH, but positively correlated with the number of large-sized follicles. These results indicate that ovarian follicular growth during the first 35 days of pregnancy in goats was characterised by a wave-like pattern and there was a close relationship between the number of FSH peaks and the number of follicular waves.Publication Effect of hCG administration on ovulation and estrus in Saanen goats subjected to short-term estrus synchronization protocol during the breeding season(Hellenic Veterinary Medical Soc, 2023-04-01) Doğan, I.; Toker, M. Berk; Aktar, A.; Yılmaz, M. M.; Udum, D.; DOĞAN, İBRAHİM; TOKER, MEHMED BERK; Aktar, Ahmet; Yılmaz, Mehmet Melih; UDUM, DUYGU; Veteriner Fakültesi; Döllenme ve Suni Tohumlama Ana Bilim Dalı; 0000-0003-1976-1814; 0000-0002-2975-2594; 0000-0001-6050-791X; 0000-0001-7052-1694; A-2794-2014; R-8366-2018; GWC-2055-2022; AAH-5167-2021; CBC-1744-2022This study aimed to compare the effect of hCG administered at 24 or 36 h following a short-term estrus synchronization treatment on the ovulation time and estrus parameters in non-lactating Saanen goats during the breeding season. The estrus cycles of does were synchronized with an intravaginal sponge containing 60 mg of medroxyprogesterone acetate (MAP) for six days, and an injection of 125 & mu;g of d-cloprostenol at the time of sponge insertion in addition to an injection of 300 IU of eCG 24h before sponge removal.After removal of the sponges, does were injected intramuscularly either 1 ml physiological saline(0.9% NaCl) solution after 12 h (Group1/Control; n=10), 100 IU hCG after 24 h (Group2; n=9) or 100 IU hCG after 36 h (Group3; n=9). Estrus behavior after sponge removal was observed twice daily for 84 h using teaser bucks and transrectal ovarian ultrasonography was performed twice a day for seven days to determine small, medium and large follicle numbers, luteal development and the time of ovulation.Blood samples were collected on the same days to determine serum progesterone (P4) and estradiol (E2) concentrations. No significant differences were observed in terms of estrus parameters, ovarian structure and serum P4 and E2 concentrations between the hCG-treated groups and the control group.Average values observed for all groups: estrus response (53.57%), the interval from sponge removal to estrus and ovulation (35.2 h and 67.86 h, respectively), duration of estrus (18.4 h), the interval from estrus onset to ovulation (50.37 h), ovulation rate (96.43%), number of ovulations (1.36), ovulatory follicle diameter (6.86 mm), corpus luteum diameter (8.22 mm), follicle and luteal growth rate (1.17 and 0.68 mm/day, respectively). In conclusion, administration of hCG at 24 or 36 h following a short-term estrus synchronization protocol does not affect ovulation time, estrus parameters, and serum P4 and E2 concentrations in goats during the breeding season.Publication Methionine, cysteine, and butylated hydroxytoluene enhance cryosurvival of ram semen on post-thaw and post-incubation time points(Springer, 2023-06-01) Toker, Mehmed Berk; Doğan, İbrahim; TOKER, MEHMED BERK; DOĞAN, İBRAHİM; Veteriner Fakültesi; Üreme ve Suni Tohumlama Ana Bilim Dalı; 0000-0003-1976-1814; 0000-0003-4033-9749; A-2794-2014; R-8366-2018Despite there have been many experiments conducted about antioxidants, the best sole or combination use of antioxidants to include as a standard ingredient to freezing extenders is yet to be found. This study was designed to investigate the different doses of methionine (2.5 and 5 mM), cysteine (1 and 2 mM), and butylated hydroxytoluene (BHT) (1 and 2 mM) for ram semen cryopreservation on post-thaw and post-incubation (6 h) time points over spermatological parameters. Semen samples were collected from Kivircik rams via electro-ejaculator in breeding season. After essential spermatological evaluations, appropriate samples were pooled then split into 7 equal aliquots to create study groups (antioxidant free control, 2.5 mM methionine, 5 mM methionine, 1 mM cysteine, 2 mM cysteine, 1 mM BHT, and 2 mM BHT). Semen samples were put into French straws (0.25 mL), and freezing procedure (two-step) was conducted via a programmable gamete freezer. At both time points, motility, HOST, PSA-FITC, and TUNEL assays were made to discover the impacts of cryopreservation and incubation process over sperm cells. Antioxidant supplemented groups yielded better results compared to the control groups in terms of various spermatological parameters not only at post-thaw time point but after incubation for 6 h of time. The study demonstrated that supplementing sperm freezing extenders with previous antioxidants may create new approaches to cryopreservation procedures, and through increasing success rate of freezing, fertility results may increase to better results in near future.Publication Effect of gnrh treatment following a short-term estrous induction protocol on estrus and ovulation in saanen goats, during the transitional period(Hellenic Veterinary Medical Soc, 2020-10-01) Doğan, İbrahim; DOĞAN, İBRAHİM; Toker, Mehmed Berk; TOKER, MEHMED BERK; Alcay, Selim; ALÇAY, SELİM; Küçüksen, Duygu Udum; Veteriner Fakültesi; Biyokimya Ana Bilim Dalı; 0000-0003-1976-1814; R-8366-2018; A-2794-2014The objective of this study was to compare the effect on the ovulation time and estrus parameters of a GnRH agonist (buserelin acetate) administered 24 or 36 h following a short-term estrus induction and synchronization treatment in non-lactating Saanen goats during the transitional period. Goats received 20 mg FGA sponges for 6 days plus 300 IU eCG and 125 mu g d-cloprostenol 24 h prior to sponge removal. After removal of the sponges, goats were given either 1 ml physiological saline (0.9% NaCI) solution (Group 1; n = 9) after 12 h, 0.004 mg GnRH (Group 2; n = 10) after 24 h or 0.004 mg GnRH (Group 3; n = 10) after 36 h. The follicle development and ovulation in the ovaries were monitored by transrectal ultrasonography starting from the sponge application until the fifth day of the estrus cycle. Blood samples were collected on the same days to determine the plasma concentrations of progesterone (P-4) and estradiol (E-2). No statistical differences among groups were detected in any synchronization parameters, ultrasonic evaluations and plasma P-4 and E-2 concentrations. The evaluation of pooled data showed that the response of Saanen goats to treatments was comparable to the results of other published trials. Results of this study indicate that administration of GnRH at 24 h or 36 h after sponge removal, at the end of a short estrus induction and synchronization protocol, does not affect plasma P-4 and E-2 concentrations, estrus parameters and ovulation time in goats, during the transition period.Publication Artificial insemination with diluted and undiluted fresh semen in goats(Indian Veterinary Journal, 2004-12-01) Doğan, İbrahim; Yerlikaya, H; Soylu, Mustafa Kemal; DOĞAN, İBRAHİM; Yerlikaya, H; SOYLU, MUSTAFA KEMAL; Veteriner Fakültesi; Çoğaltma ve Suni Tohumlama Bölümü; 0000-0003-1976-1814; R-8366-2018; ACB-3704-2022; EIC-3115-2022The objective of this study was to compare the fertility levels of goats inseminated with fresh semen and buck semen diluted with three different extenders. The fertility rates of goats inseminated in spontaneous oestrus during breeding season were found 66.6% (12/18), 60.8% (28/46), 44.4% (12/27) and 48.7% (20/41) for fresh semen, Laiciphos 488-egg yolk, sodium citrate-glucose-egg yolk and sodium citrate-egg yolk extender respectively. Reproductive performance did not differ significantly between females inseminated with undiluted or diluted semen. It is concluded that diluted buck semen with these diluents can be used successfully during the goat breeding season for inseminating does.Publication Effect of GnRH and hCG treatment following a short-term estrus synchronization protocol on ovulation and the fertility in merino ewes, during the breeding season(Hellenic Veterinary Medical Soc, 2023-10-01) Doğan, I.; Toker, M. B.; Aktar, A.; Yılmaz, M. M.; DOĞAN, İBRAHİM; TOKER, MEHMED BERK; Menekşe Yılmaz, Mine; Aktar, A.; Veteriner Fakültesi; Döllenme ve Suni Tohumlama Ana Bilim Dalı; 0000-0003-1976-1814; 0000-0002-9242-8447; A-2794-2014; R-8366-2018; AAG-6393-2020; ELR-5822-2022This study aimed to compare the effect of hCG or GnRH administered 36 h following a short-term estrus synchronization treatment on the ovulation time and pregnancy rates of Merino ewes during the breeding season. The estrus cycles of ewes were synchronized with an intravaginal sponge containing 60 mg of medroxyprogesterone acetate for 6 days, and an injection of 400 IU of eCG and 125 mu g of d-cloprostenol 24 h before sponge removal. Thirty-six h after the sponge removal, ewes were injected intramuscularly either 1 ml of physiological saline solution (control-group; n=14), 100 IU of hCG (hCG-group; n=14) or 0.004 mg of buserelin acetate (GnRH-group; n=14). The estrus behavior was observed using teaser rams and the ovulation time was monitored using transrectal ultrasonography twice daily for 96 h after the sponge removal. Ewes in estrus were allowed a single mating using fertile rams. Estrus response was higher (P<0.05) in the control group (92.86%) than in the GnRH group (50.00%). The interval from sponge removal to ovulation and from hCG to ovulation were shorterin the control group than in the hCG group(70.55, 80.83 h; 34.55, 44.83 h, respectively, P<0.05). In conclusion, administration of hCG or GnRH at 36 h following a short-term estrus synchronization protocol did not affect estrus behavior, ovarian findings and pregnancy rate in ewes during the breeding season.Publication Detection of the effect of the KISS1 gene on reproductive parameters in Saanen goats(Bursa Uludağ Üniversitesi, 2024-07-09) Dinçel, Deniz; Toker, Mehmed Berk; Doğan, İbrahim; DİNÇEL, DENİZ; TOKER, MEHMED BERK; DOĞAN, İBRAHİMThe KISS1 gene, which activates G protein-coupled receptor-54 (GPR54) and plays a crucial role in the neuroendocrine regulation of GnRH secretion, is known to encode a family of neuropeptides called kisspeptins. Therefore, the KISS1 gene is thought to be associated with sexual maturity, offspring development, and estrus. The g.2124T>A polymorphism of the KISS1 gene, is believed to affect the reproductive system, has been studied in Indonesian goat breeds, Damascus, Zarabi, Baladi, Gaddi, Kaligesing, Guanzong, Xinong Saanen and Boer goat breeds until now. These studies are generally related determining polymorphism frequencies or the effect of genotype on litter size. The study aims to determine the allele and genotype frequencies of the KISS1 gene g.2124T>A SNP by the PCR-RFLP method and define the relationship between the genotypic structures and reproductive parameters such as luteal growth, maximum corpus luteum diameter, and mating rate in Saanen goats (n=30). According to the results, the genotype frequencies in Saanen goats for the KISS1 gene g.2124T>A were 10.35%, 55.17%, and 34.48% for AA, TT and AT, respectively. Moreover, the genotypic structure did not have a statistically significant effect on the investigated fertility characteristics. The average values of expected heterozygosity (He), observed heterozygosity (Ho), the effective number of alleles (Ne), fixation index values (FIS), and the polymorphism information content (PIC) were 0.3996, 0.3448, 1.6655, 0.8629 and 0.855, respectively. The Hardy-Weinberg chi-square (χ2) value was found to be 0.5435. In conclusion, it was found necessary to study the KISS1 - g.2124T>A polymorphism in larger herds with different gene pools as a reason for the existence of genotypic variation and the narrow population size.