Browsing by Author "Karakaya, Ebru Bilen"
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Item Comparison of responses to Ovsynch between Holstein-Friesian and Swedish Red cows(Elsevier, 2010) Çelik, Yakup; Okut, Hayrettin; Wiltbank, Milo Charles; Keskin, Abdülkadir; Yılmazbaş, Gülnaz Mecitoğlu; Gümen, Ahmet; Karakaya, Ebru Bilen; Uludağ Üniversitesi/Veterinerlik Fakültesi/Klinik Bilimler Bölümü.; 0000-0003-2817-3221; AAH-1406-2021; AAG-4440-2019; AAH-3831-2021; 24473229800; 36457964000; 6602393069; 36457784500The Ovsynch protocol was designed to synchronize ovulation, thereby allowing timed artificial insemination (TAI) of all cows without detection of estrus. However, the effectiveness of Ovsynch in different breeds of dairy cows has not been previously compared. The aim of this study was to compare the response to Ovsynch in cycling lactating Holstein-Friesian (HF) and Swedish Red (SR) dairy cows. A total of 495 cyclic cows (n=347 HF, n=148 SR) were housed together and treated with Ovsynch (GnRH - 7 d - PGF2α - 56h - GnRH - 16 to 18h - TAI). Ovulatory responses, synchronization rate, maximal follicle size at the time of AI, and percentage of pregnant cows per AI (P/AI at 31 and 62 d after AI) were compared between breeds. Ultrasonography was performed during Ovsynch at first GnRH, PGF2α, at time of AI, and 7 d after AI. Ovulatory response and synchronization rate were similar in HF versus SR cows (60.2 vs. 62.2%; 88.4 vs. 88.5%, respectively). Cows that ovulated to the first GnRH of Ovsynch had smaller follicle size at AI (15.9±0.1 vs. 16.4±0.2mm). Maximal follicle size at AI was greater for HF (16.4±2.2mm) than SR (15.5±2.3mm) cows. The P/AI was greater for SR than HF cows at the 62-d pregnancy diagnosis (56.1 vs. 46.1%). In addition, pregnancy loss between 31 and 62 d of pregnancy was greater in HF (10.1%) than SR (3.5%) cows. Fertility was less in HF cows during the hot season (57.7 in cold vs. 38.1% in the hot season), whereas such a decrease was not observed in SR (60.0 in cold vs. 53.5% in the hot season) cows. Thus, although the GnRH treatments of Ovsynch were equally effective in SR and HF cows, pregnancy outcomes (P/AI at d 62 and pregnancy survival) were greater in SR than HF cows, and P/AI in SR cows was not compromised during the hot season as was found for HF cows.Item Dry period management and optimization of post-partum reproductive management in dairy cattle(Wiley, 2011-09) Wiltbank, Milo Charles; Gümen, Ahmet; Keskin, Abdülkadir; Yılmazbaş, Gülnaz Mecitoğlu; Karakaya, Ebru Bilen; Uludağ Üniversitesi/Veterinerlik Fakültesi/Kadın Hastalıkları ve Doğum Anabilim Dalı.; 0000-0003-2817-3221; AAH-1406-2021; AAG-4440-2019; AAH-3831-2021; 6602393069; 24473229800; 36457964000; 36457784500Dry period and early post-partum management are decisive factors for fertility in lactating dairy cows. Previous studies have shown that decreased dry matter intake (DMI) and increased non-esterified fatty acids (NEFA) negatively affect fertility and subsequent milk production. The traditional dry period decreases DMI prior to parturition, resulting in a decrease in energy intake. A negative energy balance increases NEFA concentration, and increased NEFA may impair the immune system, especially by decreasing neutrophil function prior to parturition. Earlier studies have shown that postpartum health disorders, including retained placenta and metritis, were correlated with periparturient neutrophil function. In addition, decreased DMI is also linked to a reduced body condition score (BCS) in dairy cows. These events in the periparturient period negatively affect fertility. Some manipulation, such as shortening the dry period, may be a solution to increased DMI in the periparturient period, preventing postpartum disorders and subsequent fertility issues. This article aims to explain the effects of shortening the dry period on reproduction and early post-partum treatments to improve fertility. In addition, timed artificial insemination protocols will be discussed for use during the post-partum period to improve fertility in dairy cows.Item Effect of presynchronization with prostaglandin F-2 alpha before the 5-d timed AI protocol on ovarian responses and pregnancy in dairy heifers(Elsevier, 2019-07-01) Karakaya, Ebru Bilen; Ribeiro, Eduardo S.; Bisinotto, Rafael S.; Santos, Jose Eduardo P.; Gümen, Ahmet; Bursa Uludağ Üniversitesi/Veteriner Fakültesi/Klinik Bilimler Anabilim Dalı.; AAH-1406-2021; 6602393069The objectives were the determine the effects of presynchronization with PGF(2)(alpha) 2 days before the 5-d timed artificial insemination (Al) protocol on ovarian responses and pregnancy per AI (P/AI) in dairy heifers. The hypothesis was that PGF(2)(alpha )m would induce responsive heifers to be in proestrus at the initiation of the timed Al protocol, which was expected to improve ovulatory responses and P/AI. Weekly cohorts of Holstein heifers were blocked by age and, within block, randomly assigned to remain as control (CON; n = 255) or receive PGF(2)(alpha) on experiment Day -10 (PG; n = 255). All heifers were subjected to the 5-d timed AI protocol (Day -8, GnRH + intravaginal progesterone controlled internal drug release insert; Day -3, PGF(2)(alpha) and insert removal; Day -2, PGF(2)(alpha); and Day 0, GnRH and AI). A subset of 22 blocks of heifers (n = 43) had their ovaries scanned by ultrasonography on experiment Days -8, -3, 0, and 2 and blood was sampled and analyzed for concentrations of progesterone on experiment Days -8, -7, -5, and -3. Pregnancy was diagnosed on experiment Days 32 and 60. On the day of the first GnRH of the timed AI protocol, PG heifers had smaller concentration of progesterone in plasma (CON = 4.5 +/- 0.5 vs. PG = 0.5 +/- 0.5 ng/mL), but larger follicular diameter (CON = 9.1 +/- 0.5 vs. PG = 11.0 +/- 0.5 mm), and a greater proportion of them had a follicle with at least 8.0 mm in diameter (CON = 61.9 vs. PG = 90.9%) than CON heifers, which resulted in increased ovulation to GnRH (CON = 19.0 vs. PG = 86.3%). Ovulation to the initial GnRH of the protocol increased as the concentration of progesterone in plasma decreased, from less than 20% when progesterone was greater than 5.0 ng/mL to more than 65% when progesterone was less than 1.0 ng/mL. More CON than PG heifers spontaenously ovulated before the day of timed AI. Detection of estrus on the day of timed AI did not differ between treatments (CON = 50.9 vs. PG = 46.6%), but P/AI on Days 32 (CON = 52.9 vs. PG = 61.1%) and 60 (CON = 49.0 vs. PG = 57.1%) after inseminationtended to be greater for PG than CON; however, the benefit to presynchronization was observed in heifers inseminated with conventional (CON = 54.7 vs. PG = 67.4%), but not in heifers inseminated with sex-sorted semen (CON = 50.9 vs. PG = 52.8%). Administration of PGF(2)(alpha) 2 days before initiating the timed AI protocol induced heifers to be in proestrus, which enhanced ovulation to the initial GnRH and favored pregnancy per AI, particularly in heifers inseminated with conventional semen.Item Fertility in dairy cows after artificial insemination using sex-sorted sperm or conventional semen(Wiley, 2014-04) Alkan, Ali; Taşdemir, Umut; Santos, José Eduardo P.; Karakaya, Ebru Bilen; Yılmazbaş, Gülnaz Mecitoğlu; Kesin, Abdülkadir; Gümen, Ahmet; Uludağ Üniversitesi/Veterinerlik Fakültesi/Klinik Bilimler Bölümü.; 0000-0003-2817-3221; AAH-1406-2021; AGY-3496-2022; AAH-3831-2021; AAG-4440-2019; 36457784500; 36457964000; 24473229800; 6602393069Contents The aim of this study was to compare pregnancy per artificial insemination (P/AI) after timed AI with sex-sorted sperm (SS) or conventional semen (CS) in lactating dairy cows. Cyclic cows (n=302) were synchronized by Ovsynch and randomly assigned into two groups at the time of AI. Cows with a follicle size between 12 and 18mm and clear vaginal discharge at the time of AI were inseminated with either frozen-thawed SS (n=148) or CS (n=154) of the same bull. A shallow uterine insemination was performed into the uterine horn ipsilateral to the side of probable impending ovulation. Pregnancy per AI on Day 31 tended (p=0.09) to be less for SS (31.8%) than CS (40.9%). Similarly, P/AI on Day 62 was less (p=0.01) for cows inseminated with SS (25.7%) compared with CS (39.0%). The increased difference in fertility between treatments from Days 31 to 62 was caused by the greater (p=0.02) pregnancy loss for cows receiving SS (19.2%) than CS (4.8%). Cow parity (p=0.02) and season (p<0.01) when AI was performed were additional factors affecting fertility. Primiparous cows had greater P/AI than multiparous cows both on Day 31 (41.7% vs 25.0% in SS and 53.0% vs 31.8% in CS groups) and on Day 62 (33.3% vs 20.5% in SS and 48.5% vs 31.8% in CS groups). During the hot season of the year, P/AI on Day 31 was reduced (p=0.01) in the SS group (19.6%) when compared with the rates during the cool season (38.1%). In conclusion, sex-sorted sperm produced lower fertility results compared to conventional semen even after using some selection criteria to select most fertile cows.Item 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 Reducing the duration between gonadotropin-releasing hormone (GnRH) and prostaglandin F-2 alpha treatment in the Ovsynch protocol to 6 days improved ovulation to second GnRH treatment, but inclined to reduce fertility(Elsevier, 2013-06) Alkan, Ali; Mecitoğlu, Gülnaz Yılmazbaş; Karakaya, Ebru Bilen; Keskin, Abdülkadir; Gümen, Ahmet; Uludağ Üniversitesi/Veterinerlik Fakültesi/Veteriner Doğum ve Jinekoloji Bölümü.; 0000-0003-2817-3221; AAG-4440-2019; AAH-3831-2021; AGY-3496-2022; AAH-1406-2021; 36457964000; 36457784500; 24473229800; 6602393069The aim of this study was to test Ovsynch (OVS) versus modified OVS (decreasing the interval between first GnRH and PGF(2 alpha) to 6 d) protocols on pregnancy per artificial insemination (AI) and OVS outcomes in cyclic dairy cows. Cyclic cows (n = 920) were assigned to 1 of 2 groups: the OVS7 group (n = 459) received the OVS protocol [GnRH treatment, PGF(2 alpha) treatment 7 d later, a second GnRH (GnRH2) treatment 56 h later, and timed AI (TAI) 16 to 18 h after the GnRH2 treatment], and the OVS6 group (n = 461) received a modified OVS protocol, in which the interval between the first GnRH and PGF(2 alpha) was decreased to 6 d (GnRH treatment, PGF(2 alpha) treatment 6 d later, GnRH2 treatment 56 h later, and TAI 16 to 18 h after the GnRH2 treatment). The response to the first GnRH of OVS was similar between OVS7 (54.5%, 250/459) and OVS6 (54.2%, 250/461) groups. The ovulatory response to GnRH2 of OVS was higher in OVS6 (91.3%, 421/461) than OVS7 (84.5%, 388/459). The follicle size (mean +/- standard error of the mean) at the time of TAI was smaller in OVS6 (15.23 +/- 0.11 mm) than OVS7 (16.04 +/- 0.11 mm). When all cows were evaluaed, the pregnancy per AI at 31 d tended to be lower in OVS6 (38.0%, 175/461) than in OVS7 (43.8%, 201/459). Moreover, the pregnancy per AI at 31 d was lower in OVS6 (40.9%, 172/421) compared with OVS7 (50.3%, 195/388) in synchronized cows. In conclusion, although the modified OVS protocol decreased the follicle size at the time of AI and increased the ovulatory response to GnRH2 of OVS, it unexpectedly reduced fertility in cyclic lactating dairy cows.