Browsing by Author "Keskin, Abdulkadir"
Now showing 1 - 17 of 17
- Results Per Page
- Sort Options
Item Associations between GH, PRL, STAT5A, OPN, PIT-1, LEP and FGF2 polymorphisms and fertility in holstein-friesian heifers(Kafkas Üniversitesi Veteriner Fakültesi Dergisi, 2017) Yılmaz, Onur; Okut, Hayrettin; Ata, Nezih; Öner, Yasemin; Yılmazbaş, Mecitoğlu Gülnaz; Keskin, Abdulkadir; Uludağ Üniversitesi/Ziraat Fakültesi/Zooteknik, Biyometri ve Genetik Bölümü.; Uludağ Üniversitesi/Veteriner Fakültesi.; 0000-0002-2904-8986; 0000-0003-2817-3221; ABB-3181-2020; AAG-4440-2019; 9634793800; 36457964000; 24473229800In this study, it was aimed to investigate polymorphisms in seven genes (GH, PRL, STAT5A, OPN, PIT-1, LEP and FGF2) related to reproductive traits in dairy heifers. Frequency distributions of the genotypes between fertile and repeat breeder heifers groups were investigated. Allele effects on fertility were also analyzed. Blood samples were taken from a total of 160 Holstein-Friesian heifers and they were divided into two groups according to their artificial insemination numbers (AI). The heifers becoming pregnant after the first AI were used as the fertile heifers (FH, n= 80) and the heifers with 3 or more equal AIs were accepted as the repeat breeder heifers (RBH, n= 80). All the animals were genotyped by the PCR-RFLP method for seven genes and the association works were performed for 145 animals (RBH, n= 79; FH n= 66). For all loci investigated, two alleles and three genotypes were found for overall population with the exception that PRL locus had two alleles and two genotypes. The chi-square test (.2) revealed that the whole population and the two groups separately were at Hardy-Weinberg equilibrium. The genotype distributions of PIT-1 and STAT5A conspicuously differed between the FH and the RBH groups; however, these differences were not found significant. Association of GH-AB genotype was found significant on AI number for the first pregnancy. Mixed effect logistic regression model was used to investigate the allele effects on fertility. No linkage disequilibrium was detected between the investigated loci.Item Biochemical and histochemical detection of the sialic acids in mammary tumours of bitches(Ecole Nationale Veterinaire Toulouse, 2005-05) Seyrek, Kamil; Kıral, Funda Kargın; Musal, Bayazıt; Toplu, Nihat; Seyrek, Kamil İntaş; Keskin, Abdulkadir; Uludaǧ Üniversitesi/Veterinerlik Fakültesi/Doğum ve Jinekoloji Anabilim Dalı.; AAH-7292-2019; 6603409870; 24473229800This study describes the expression and localisation of sialic acid in mammary tumours in bitches. Tissue total sialic acid (TSA) concentrations were detected spectrophotometrically. Localisation of sialic acids in mammary tissue was visualised using the biotin-conjugated Sambucus nigra lectin (SNA), specific for alpha 2,6-linked sialic acid, and Maaickia amurensis lectin (MAL), specific for alpha 2,3-linked sialic acid. The mean value of tissue TSA of malignant tumours (1.46 +/- 0.14 mu mol/g protein) was significantly higher (p < 0,001) than that in healthy tissues (0.26 +/- 0.07 mu mol/g protein) as well as in tissues with benign types of tumour (0.50 +/- 0.06 mu mol/g protein). We could not find a significant difference in sialic acid concentrations between adenomas and normal tissue (p > 0.05). Tissue TSA content in the same type of tumours was not always equal. In histochemical analyses both the staining intensity and localisation patterns of SNA and MAL showed marked differences. The staining for SNA and MAL was only low or not present in normal mammary tissues but high in carcinomas. In malign tumours binding sites for SNA were predominantly in epithelial cells and in individual cells infiltrating the fibrous tissue. However, the binding sites for MAL were predominantly in fibrous tissue, capillary and lymphatic endothelia. Contrary to malignant tumours, a moderate staining was observed in benign tumours. The staining was mainly in epithelial cells, in fibrocytes and in myoepithelial cells. It was not always the case that the same type of tumours revealed the same staining intensity localisation for the lectins. The results obtained from the present study suggest that elevated levels of sialic acid in malignant mammary tumours may play an important role in the detachment of carcinoma cells from the primary tumour and would be of critical importance for the metastasis of turnout cells.Item Comparing of response to ovsynch protocol in ovular and anovular lactating dairy cows(Wiley, 2009-09) Karayakaya, Emre; Mutis, V.; Mecitoğlu, Gülnaz Yılmazbaş; Keskin, Abdulkadir; Gümen, Ahmet; Uludağ Üniversitesi/Veteriner Fakültesi/Klinik Bilimler Bölümü.; 0000-0003-2817-3221; AAG-4440-2019; AAH-3831-2021; AAH-1406-2021Item Comparison of the efficacy of enrofloxacin and lactobacillus plantarum cell-free supernatant treatments on vaginitis in ewes(Bursa Uludağ Üniversitesi, 2022-08-10) Güner, Barış; Kısadere, İhsan; Tavşanlı, Hakan; Demirbilek, Serpil Kahya; Keskin, Abdulkadir; Bursa Uludağ Üniversitesi/Veteriner Fakültesi/Mikrobiyoloji Anabilim Dalı.; Bursa Uludağ Üniversitesi/Veteriner Fakültesi.; 0000-0001-6138-7163; 0000-0001-7149-0009The aim of the study was to investigate the effect of different intravaginal treatment strategies on the vaginal discharge score, vaginal microbiota, bacterial and Enterobacteriaceae counts in nulliparous Merino ewes. All ewes (n=45) received intravaginal sponges containing 60 mg medroxyprogesterone acetate for 7 days and allocated into three equal groups (n=15). Sponges were injected Lactobacillus plantarum cell-free supernatant (SUPER), enrofloxacin (ENRO), or physiologic saline (CON) prior to sponge insertion. At sponge removal, 500 IU equine chorionic gonadotropin (eCG) were administered in all ewes. For the detection of vaginal microbiota, bacterial and Enterobacteriaceae counts, samples were collected prior to sponge insertion, at sponge withdrawal, and 48 h later after sponge withdrawal. Vaginal discharge score was not different in ENRO (2.26±0.18) and SUPER (2.20±0.14) compared to CON (2.46±0.16). The time-dependent alteration was significant for the mean bacterial and Enterobacteriaceae count in all groups (P<0.05). Bacterial counts were found to be lower in ENRO (5.50±0.17) than SUPER (6.31±0.19) and CON (6.07±0.15) at sponge removal (P<0.05). In addition, SUPER (3.74±0.21) and ENRO (3.49±0.27) had lower Enterobacteriaceae counts compared to CON (4.78±0.21) at sponge removal (P<0.01). The most frequently isolated bacteria species were Trueperella pyogenes (28.9%) and Escherichia coli (46.7%). In conclusion, treatment with enrofloxacin or cell-free supernatant decreased the Enterobacteriaceae counts in ewes. Comprehensive studies are needed to assess the effectiveness of lactic acid bacteria as an antibiotic-free treatment strategy on vaginitis in ewes that were synchronized with progesterone impregnated intravaginal sponge.Item Conception rate in lactating dairy cows after artificial insemination with sexed semen(Wiley, 2011-08) Karakaya, Ebru; Keskin, Abdulkadir; Mecitoğlu, Gülnaz Yılmazbaş; Alkan, Ali; Doğan, Ramazan; Gümen, Ahmet; Uludağ Üniversitesi/Veterinerlik Fakültesi/Veterinerlik Doğum ve Jinekolojisi Bölümü.; 0000-0003-2817-3221; AAH-1555-2021; AAH-3831-2021; AAG-4440-2019; AAH-1406-2021Item Diagnosis of various teat lesions in dairy cows by ultrasonography(Indian Veterinary Journal, 2005-11) Nak, Deniz; Nak, Yavuz; Keskin, Abdulkadir; Uludaǧ Üniversitesi/Veterinerlik Fakültesi.; AAH-5494-2021; 9280090000; 8615464000; 24473229800In this study, 62 teats obtained from slaughtered cows and 51 teats obtained from live cows were compared by ultrasonography and classic clinical examination methods. After examining by classic clinical examination methods, all teats were examined using B-mode ultrasound equipment, with a 5 MHz linear array transducer. When compared with classic clinical examination methods, ultrasonographic examination more readily detected stenosis, obstruction and other anomalies in all parts of the teats except for those in the ductus papillaris. Ultrasonographic examination was also beneficial for the determination of the shape and size of the stenosis, obstruction and other anomalies of the teats.Publication Distributions of CYP19, ERα and PGR allele frequencies between fertile and subfertile Holstein-Friesian heifers(Kafkas Üniversitesi, 2015-11-01) Keskin, Abdulkadir; Öner, Yasemin; Yılmazbaş-Mecitoğlu, Gülnaz; Güner, Barış; Karakaya, Ebru; Elmacı, Cengiz; Gümen, Ahmet; KESKİN, ABDULKADİR; ÖNER, YASEMİN; MECİTOĞLU, GÜLNAZ; Güner, Barış; Karakaya, Ebru; ELMACI, CENGİZ; GÜMEN, AHMET; Uludağ Üniversitesi/Veteriner Fakültesi/Jinekoloji Anabilim Dalı.; Uludağ Üniversitesi/Ziraat Fakültesi/Hayvan Bilimleri Biyometri ve Genetik Bölümü.; 0000-0002-2904-8986; 0000-0003-2817-3221; 0000-0001-6414-6752; 0000-0003-4837-1858; 0000-0003-4819-0221; 0000-0002-3607-4365; V-7882-2019; AIF-3815-2022; ABB-3181-2020; AAH-3831-2021; AAH-1406-2021; AAG-4440-2019; AGY-3496-2022; ABG-2047-2020The aim of this study was to investigate the gene and genotype distributions of some mutations in the aromatase cytochrome P450 (CYP19), estrogen receptor alpha (ER alpha), and progesterone receptor (PGR) genes in fertile and subfertile Holstein-Friesian heifers using the PCR-RFLP method and comparing the distributions between groups. A total of 106 heifers were included the study, and the heifers that became pregnant after the first artificial insemination (n=51) were used as a fertile group. Heifers (n=55) with equal and more than 3 AIs were accepted as a subfertile heifers. Blood samples from all of the heifers were obtained for DNA isolation. While two alleles and three genotypes were found at the PGR and ER alpha loci, two alleles and two genotypes were detected at the CYP19 locus. The A allele and AA genotype, G allele and GG genotype, and C allele and CT genotype were found to be predominant in CYP19, ER alpha and PGR, respectively. According to the chi-square test (chi(2)), two of the groups investigated were in Hardy-Weinberg equilibrium for all gene loci. There were no differences detected in allele or genotype frequencies between the fertile and subfertile heifers.Item The effect of intrauterine cephapirin treatment after insemination on conception rate in repeat breeder dairy cows subjected to the progesterone-based Ovsynch protocol(TÜBİTAK, 2012) Alkan, Ali; Taşdemir, Umut; Okut, Hayrettin; Gümen, Ahmet; Mecitoğlu, Gülnaz Yılmazbaş; Keskin, Abdulkadir; Karakaya, Ebru; Uludağ Üniversitesi/Veteriner Fakültesi/Jinekoloji ve Doğum Anabilim Dalı.; 0000-0003-2817-3221; AAG-4440-2019; AAH-1406-2021; AAH-3831-2021; 6602393069; 36457964000; 24473229800; 36457784500Subclinical endometritis contributes to repeat breeder syndrome in dairy cows. This study evaluated the effect of intrauterine cephapirin benzathine administration aft er timed artificial insemination (TAI) on the conception rate (CR) in repeat breeder dairy cows. To determine the antibiotic effects, all cows (n = 335) that had more than 3 services with no clinical abnormalities of the reproductive tract received the same combined synchronisation protocol: an ear implant containing progestagen using the Ovsynch protocol and a third gonadotropin-releasing hormone (GnRH) administration 7 days aft er TAI. Cows in the treatment group (TRT; n = 160) received intrauterine cephapirin 12 h aft er TAI, and cows in the control group (CON; n = 175) did not receive intrauterine antibiotics. The percentage of cows that responded to the first (67.5% in TRT, 70.9% in CON) and second (98.8% in TRT, 97.1% in CON) GnRH of Ovsynch was similar between the groups. In addition, the response to the third GnRH administration aft er TAI (88.1% in TRT, 83.9% in CON) did not differ between the groups. However, there was no effect of the cephapirin administration on CR on days 31 and 62 in the repeat breeder cows (43.8% in TRT and 44.0% in CON; 39.4% in TRT and 40.6% in CON, respectively). Thus, post-TAI intrauterine cephapirin administration was not found to be useful for the treatment of potential subclinical endometritis in repeat breeder dairy cows.Item The effect of ovulatory follicle size at the time of insemination on pregnancy rate in lactating dairy cows(TÜBİTAK, 2015-09-28) Okut, Hayrettin; Keskin, Abdulkadir; Mecitoğlu, Gülnaz; Bilen, Ebru; Güner, Barış; Orman, Abdulkadir; Gümen, Ahmet; Uludağ Üniversitesi/Veteriner Fakültesi/Jinekoloji ve Doğum Anabilim Dalı.; Uludağ Üniversitesi/Veteriner Fakültesi/Zootekni Anabilim Dalı.; 0000-0001-9138-4422; 0000-0003-2817-3221; AAG-9134-2021; AAG-4440-2019; AAH-1406-2021; AAH-3831-2021; 24473229800; 36457964000; 57040965000; 57188841418; 24335834100; 6602393069The aims of this study were to determine the factors that affect follicle size at the time of artificial insemination (AI) and to detect the relationship between ovulatory follicle size at the time of AI and pregnancy rate in dairy cows. A total of 1428 follicle size measurements were obtained from Holstein-Friesian (HF) and Swedish Red (SR) cows that were inseminated with the fixed-timed AI protocols used in this study. Follicle size was affected by breed (P - 0.0001), milk production (P - 0.01), parity (P - 0.05), and season (P = 0.04). Follicle size was greater (P = 0.0001) in the HF (15.55 mm) than the SR cows (14.88 mm). Multiparous cows had larger (P = 0.04) follicles (15.35 mm) than the primiparous cows (15.07 mm). Cows with follicle sizes between 13.5 and 17.5 mm were more likely to be pregnant than cows with other sizes follicles (P < 0.01). Embryonic loss was lower (P < 0.01) in cows with follicle sizes between 13.5 and 16.5 mm. Thus, the follicle size was affected by breed, milk production, parity, and season. Pregnancy and embryonic loss in lactating dairy cows were significantly related to follicle size.Item The effect of preovulatory follicle size at the time of insemination on pregnancy in lactating dairy cows(Wiley, 2011-09) Çelik, Yakup; Okut, Hayrettin; Wiltbank, Milo C.; Keskin, Abdulkadir; Mecitoğlu, Gülnaz Yılmazbaş; Karakaya, Emre; Gümen, Ahmet; Uludağ Üniversitesi/Veterinerlik Fakültesi/Veterinerlik Doğum ve Jinekolojisi Anabilim Dalı.; 0000-0003-2817-3221; AAH-3831-2021; AAG-4440-2019; AAH-1406-2021; 36457964000Item The effect of progesterone based ovsynch protocol and gnrh treatment after artificial insemination on conception rate in repeat breeder cows(Uludağ Üniversitesi, 2010-12-30) Taşdemir, Umut; Çelik, Yakup; Okut, Hayrettin; Keskin, Abdulkadir; Gümen, Ahmet; Mecitoğlu, Gülnaz Yılmazbaş; Karakaya, Ebru; Uludağ Üniversitesi/Veteriner Fakültesi.The aim of this study was to test the combined treatment protocol for improving fertility in repeat breeder cows by eliminating most of the hormonal etiological factors. Total 238 clinically healthy lactating dairy cows were included in the study; 175 dairy cows had more than three services (Repeat Breeder Cows) and 63 dairy cows had less than three services (Normal Cows). Ovsynch protocol was applied at random stages of the estrous cycle to all cows and exogenous progesterone (ear implant) was applied between GnRH and PGF2α of Ovsynch. In addition, GnRH was administrated seven days after artificial insemination (GnRH–progesterone– 7d–PGF2α–2d–GnRH–16h–AI–7d–GnRH). Response to the first GnRH of Ovsynch was greater (P<0.003) in repeat breeders (70.9%) than in normal cows (49.2%). However percentages of cows to responded to 2nd and 3rd GnRH were not different between groups (97.1%, 83.9% in repeat breeders and 98.4%, 87.1% in normal cows, respectively). Conception rates were similar at 31 and 62 d between groups (44.0%, 40.6% in repeat breeders and 47.6%, 42.9% in normal cows, respectively). In addition, embryonic loss was also similar in groups (7.8% in repeat breeders and 10.0% in normal cows). Thus, conception rate and response to hormonal treatments of the combined protocol except first GnRH were found to be similar in both repeat breeder and normal cows. So the combined protocol could be effective treatment for improving conception rate in repeat breeder cows.Item Effects of GnRH, PGF2 alpha and oxytocin treatments on pregnancy rate at the time of artificial insemination in lactating dairy cows(Wiley, 2009-09) Çevik, Sevgi; Mecitoğlu, Gülnaz Yılmazbaş; Keskin, Abdulkadir; Gümen, Ahmet; Karakaya, Emre; Uludağ Üniversitesi/Veteriner Fakültesi/Kadın Hastalıkları ve Doğum Anabilim Dalı.; 0000-0003-2817-3221; AAG-4440-2019; AAH-3831-2021; AAH-1406-2021Item Effects of reducing interval from gnrh to pgf2 alpha in ovsynch protocol on pregnancy rate in cyclic lactating dairy cows(Wiley, 2009-09) Karakaya, Emre; Çelik, Yaren; Gümen, Ahmet; Keskin, Abdulkadir; Mecitoğlu, Gülnaz Yılmazbaş; İntaş, Kamil Seyrek; Uludağ Üniversitesi/Veterinerlik Fakültesi/Veterinerlik Doğum ve Jinekolojisi Anabilim Dalı.; 0000-0003-2817-3221; AAH-1406-2021; AAH-7292-2019; AAH-3831-2021; AAG-4440-2019Item Fertility of lactating dairy cows inseminated with sex-sorted or conventional semen after Ovsynch, Presynch–Ovsynch and Double-Ovsynch protocols(Wiley, 2019-02) Santos, Jose E. P.; Gümen, Ahmet; Karakaya, Ebru Bilen; Yılmazbaş, Gülnaz Mecitoğlu; Keskin, Abdulkadir; Güner, Barış; Serim, Enes; Gümen, Ahmet; Uludağ Üniversitesi/Veteriner Fakültesi/Doğum ve Jinekoloji Anabilim Dalı.; 0000-0002-3607-4365; 0000-0003-2727-387X; 0000-0001-6414-6752; 0000-0003-2817-3221; AAH-1406-2021; AAH-3831-2021; AAG-4440-2019; 36457964000; 24473229800; 57188841418; 57204617496; 6602393069The objective was to compare pregnancy per artificial insemination (P/AI) with conventional (CS) or sex-sorted semen (SS) in dairy cows subjected to one of the three timed AI protocols. Cows (n = 356) were randomly assigned to synchronization with Ovsynch (OVS), Presynch–Ovsynch (PO) or Double-Ovsynch (DO) and inseminated on Day 77 ± 3 postpartum with either frozen-thawed SS (n = 182) or CS (n = 184) of the same bull. More cows were cyclic at the beginning of breeding Ovsynch increased (p < 0.01) with presynchronization and it was greater for DO than PO (OVS = 78.5%, PO = 85.1%, DO = 95.6%). Overall, P/AI for SS and CS increased with presynchronization (p < 0.05) on Days 31 (OVS = 35.5%, PO = 47.1%, DO = 48.3%) and 62 (OVS = 30.1%, PO = 43.8%, DO = 43.9%). Regardless of synchronization treatments, insemination with SS reduced P/AI (p < 0.02) on Days 31 (38.1% vs. 50.6%) and 62 (34.5% vs. 45.6%) compared with CS. No interaction was observed between synchronization treatment and type of semen for P/AI, although in cows receiving CS, P/AI was numerically greatest for PO (OVS = 42.0%, PO = 59.3%, DO = 49.0%), and in cows receiving SS, it was numerically greatest for those inseminated following DO (OVS = 27.9%, PO = 35.5%, DO = 47.6%). Thus, presynchronization improved P/AI in cows inseminated with sex-sorted or conventional semen.Item Fertility of lactating dairy cows treated with different timed artificial insemination protocols before using of sex-sorted sperm vs. conventional semen(Wiley, 2014) Bisinotto, Rafael; Santos, José Eduardo P.; Gümen, Ahmet; Bilen, Ebru; Yılmazbaş, Gülnaz Mecitoğlu; Keskin, Abdulkadir; Alkan, Ali; Uludağ Üniversitesi.; 0000-0003-4837-1858; 0000-0003-2817-3221; AIF-3815-2022; AAH-3831-2021; AAG-4440-2019; AAH-1406-2021Item Presynchronization with Double-Ovsynch improves fertility at first postpartum artificial insemination in lactating dairy cows(Elsevier Science, 2012-12) Herlihy, Mary M.; Giordano, Julio O.; Souza, Alex H.; Ayres, Henderson; Ferreira, Roberta M.; Nascimento, Anibal B.; Guenther, Jerry N.; Gaska, Jerry M.; Kacuba, S. J.; Crowe, Mark A.; Butler, Stephen T.; Wiltbank, Milo C.; Keskin, Abdulkadir; Uludağ Üniversitesi/Veteriner Fakültesi/Doğum ve Jinekoloji Ana Bilim Dalı.; AAH-3831-2021; 24473229800The objective of this study was to compare circulating progesterone (P4) profiles and pregnancies per AT (P/AI) in lactating dairy cows bred by timed artificial insemination (TAT) following Ovsynch-56 after 2 different presynchronization protocols: Double-Ovsynch (DO) or Presynch-Ovsynch (PS). Our main hypothesis was that DO would increase fertility in primiparous cows, but not in multiparous cows. Within each herd (n = 3), lactating dairy cows (n = 1,687; 778 primiparous, 909 multiparous) were randomly assigned to DO [n = 837; GnRH-7d-PGF(2 alpha)-3d-GnRH-7d-Ovsynch-56 (GnRH-7d-PGF(2 alpha)-56h-GnRH-16hTAI)] or PS (n = 850; PGF(2 alpha)-14d-PGF(2 alpha)-12d-Ovsynch-56). In 1 herd, concentrations of P4 were determined at the first GnRH (GnRH1) of Ovsynch-56 and at d 11 after TAI (n = 739). In all herds, pregnancy was diagnosed by palpation per rectum at 39 d. In 1 herd, the incidence of late embryo loss was determined at 74 d, and data were available on P/AI at the subsequent second service. Presynchronization with DO reduced the percentage of animals with low P4 concentrations (<0.50 ng/mL) at GnRH1 of Ovsynch-56 (5.4 VS. 25.3%, DO vs. PS). A lesser percentage of both primiparous and multiparous cows treated with DO had low P4 concentrations at GnRH1 of Ovsynch-56 (3.3 vs. 19.7%, DO vs. PS primiparous; and 8.8 vs. 31.9%, DO vs. PS multiparous). Presynchronization with DO improved P/AI at the first postpartum service (46.3 vs. 38.2%, DO vs. PS). Statistically, a fertility improvement could be detected for primiparous cows treated with DO (52.5 vs. 42.3%, DO vs. PS, primiparous), but only a tendency could be detected in multiparous cows (40.3 vs. 34.3%, DO vs. PS, multiparous), consistent with our original hypothesis. Presynchronization treatment had no effect on the incidence of late embryo loss after first service (8.5 vs. 5.5%, DO vs. PS). A lower body condition score increased the percentage of cows with low P4 at GnRH1 of Ovsynch-56 and reduced fertility to the TAI. In addition, P4 concentration at d 11 after TAI was reduced by DO. The method of presynchronization at first service had no effect on P/AI at the subsequent second service (34.7 vs. 36.5%, DO vs. PS). Thus; presynchronization with DO induced cyclicity in most anovular cows and improved fertility compared with PS, suggesting that DO could be a useful reproductive management protocol for synchronizing first service in commercial dairy herds.Item Siklik ve siklik olmayan sütçü ineklerde ovsynch protokolüne verilen yanıtın karşılaştırılması(Uludağ Üniversitesi, 2010-11-26) Taşdemir, Umut; Alkan, Ali; Okut, Hayrettin; Keskin, Abdulkadir; Mecitoğlu, Gülnaz Yılmazbaş; Karakaya, Ebru; Gümen, Ahmet; Uludağ Üniversitesi/Veteriner Fakültesi.Ovsynch protokolü, iki GnRH ve bir PGF2α uygulamasından oluşan ve ovulasyonu sinkronize eden zaman ayarlı suni tohumlama (ST) protokolüdür (GnRH–7gün-PGF2α–56saat–GnRH–18 saat-ST). Bu protokolün avantajı, östrus tespitine gerek kalmadan ST’ye olanak sağlamasıdır. Yapılan çalışmalarda Ovsynch protokolü hem siklik hem de siklik olmayan ineklerde ovulasyonu başarılı bir şekilde sinkronize etmesine rağmen, elde edilen gebelik oranlarında farklılıklar mevcuttur. Bu çalışmanın amaçları; 1) siklik olmayan ineklerde Ovsynch öncesi en büyük follikül çapını belirlemek 2) siklik olmayan ineklerde follikül çapının Ovsynch sonuçları üzerine etkisini saptamak 3) siklik ve siklik olmayan ineklerde Ovsynch protokolüne verilen yanıtı karşılaştırmaktı. İneklerin siklik olup olmadıklarını saptamak amacıyla 7 gün arayla iki kez ovaryumların ultrasonografik muayenesi yapıldı. Çalışma, 181 baş siklik, 69 baş ise siklik olmayan toplam 250 baş inekte gerçekleştirildi. Siklik olmayan ineklerde Ovsynch öncesi en büyük follikül çapı 16-24 mm olan inek oranı (%44.9), 9-15 mm (P<0.05; %28.9) ve ≥ 25 mm (P<0.01; %26.0) follikül çaplarına sahip ineklerin oranından daha yüksek saptandı. Ovsynch’in ilk GnRH’na alınan yanıt, siklik olmayan ineklerde (%97.1, 67/69) siklik ineklere (%57.5, 104/181) göre daha fazla saptandı (P<0.0004). Ovsynch’in ikinci GnRH’ına yanıt, siklik (%88.4,160/181) ve siklik olmayan (%85.5, 59/69) ineklerde benzer tespit edildi. Aynı zamanda 31. gün gebelik oranında siklik (%39.8, 72/181) ve siklik olmayan (%31.9, 22/69) inekler arasında fark bulunmadı. Bununla birlikte ≥25 mm follikül çapına sahip siklik olmayan ineklerin Ovsynch’in ikinci GnRH’ına yanıtı ve gebelik oranı (sırasıyla; %100 ve %55.5), follikül çapı 9-15 mm (sırasıyla; %75.0 ve %15.0) ve 16-24 mm (sırasıyla; %83.8 ve %29.0) olan ineklere göre daha yüksek saptandı. Sonuç olarak, siklik olmayan ineklerin Ovsynch protokolüne en az siklik inekler kadar yanıt verdiği ve Ovsynch başlangıcında siklik olmayan ineklerde en büyük follikül çapının ikinci GnRH’a yanıtı ve gebelik oranını etkilediği saptandı.