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    Effect of presynchronization with prostaglandin F2? before the 5-d timed AI protocol on ovarian responses and pregnancy in dairy heifers
    (Elsevier Science Inc, 2019) Karakaya-Bilen, Ebru; Ribeiro, Eduardo S.; Bisinotto, Rafael S.; Gumen, Ahmet; Santos, Jose Eduardo P.
    The 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. (C) 2019 Published by Elsevier Inc.
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    Fertility of lactating dairy cows inseminated with sex-sorted or conventional semen after Ovsynch, Presynch-Ovsynch and Double-Ovsynch protocols
    (Wiley, 2019) Karakaya-Bilen, Ebru; Yilmazbas-Mecitoglu, Gulnaz; Keskin, Abdulkadir; Guner, Baris; Serim, Enes; Santos, Jose E. P.; Gumen, Ahmet
    Contents The 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.
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    Prolonged gestation in a Swedish Red cow due to fetal unilateral adrenal gland dysgenesis
    (Tubitak Scientific & Technological Research Council Turkey, 2019) Karakaya Bilen, Ebru; Akkoc, Ahmet; Guner, Baris; Yilmazbas Mecitoglu, Gulnaz; Gumen, Ahmet; Keskin, Abdulkadir
    A 5-year-old Swedish Red cow, pregnant for 465 days according to the last insemination record, was presented in this case. She conceived by artificial insemination at spontaneous estrus using frozen-thawed sperm of Swedish Red sire. No abnormalities were detected during gestation and no clinical signs of parturition at the expected time of delivery were noted. She was reexamined several times to eliminate breeding records error and, once prolonged gestation was confirmed, parturition was induced. The calf survived birth but died 10 min after birth. A macroscopically giant fetus was diagnosed. Following necropsy, some congenital anomalies were noticed. While the structure of the right adrenal gland was normal, disorganized soft tissue was observed in the left one, in which cortical and medullar regions could not be distinguished. The calf's pituitary gland was also normal. Thus, prolonged gestation was attributed to a case of unilateral adrenal gland dysgenesis.
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    The effect of supplementation of follicle-stimulating hormone (FSH) into the Ovsynch protocol to increase the pregnancy rate in cyclic lactating dairy cows
    (Veterinarni A Farmaceuticka Univerzita Brno, 2022) Yilmazbas-Mecitoglu, Gulnaz; Keskin, Abdulkadir; Karakaya-Bilen, Ebru; Tasdemir, Umut; Gumen, Ahmet
    The aim of this study was to determine the effects of the follicle stimulating hormone (FSH) supplemented in the Ovsynch protocol on pregnancy per timed artificial insemination (P/TAI) in cyclic dairy cows. All cows (n = 383) included in the study received the Ovsynch protocol. The cows in FSH3 (n = 92), FSH4 (n = 88), and FSH3&4 (n = 91) were administered 20 mg FSH on day 3, or day 4, or both on days 3 and 4 of the protocol, respectively, whereas the control group (n = 112) did not receive any FSH treatment. The mean follicle number at TAI and ovulation number after TAI were similar among the FSH groups. However, the mean follicular size was smaller (similar to 14.9 mm, P = 0.02) in FSH4 compared to the other groups (similar to 15.9 mm). Pregnancy/TAI of the FSH4 group on day 31 (59.1%) and day 62 (53.4%) was higher than those of other groups on day 31 (45.5% in control, 45.7% in FSH3, and 46.2% in FSH3&4) and day 62 (42.9% in control, 43.5% in FSH3, and 40.7% in FSH3&4), but the difference was non-significant. Likewise, FSH4 (62.7%) had more (P = 0.05) P/TAI than the other groups (48.6% in control, 47.7% in FSH3, and 49.4% in FSH3&4) in synchronized cows. The cows which responded to the first gonadotropin-releasing hormone (GnRH) of Ovsynch in the FSH4 group (64.8%) had higher (P < 0.02) P/AI rate than the responding control cows (44.6%). We concluded that application of FSH on day 4 in cyclic cows which were responsive to the Ovsynch protocol can yield higher pregnancy rates, but more studies are needed to better demonstrate this potential effect.
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    The ovulatory response to human chorionic gonadotropin administration on day 4 post timed artificial insemination improved fertility in repeat breeder cows
    (Veterinarni A Farmaceuticka Univerzita Brno, 2021) Yilmazbas-Mecitoglu, Gulnaz; Gumen, Ahmet; Karakaya-Bilen, Ebru; Keskin, Abdulkadir; Guner, Baris; Cakircali, Rabia
    This study focused on determining the success of inducing endogenous progesterone source (by formation of accessory corpus luteum) by human chorionic gonadotropin (hCG) administration on day 4 post timed artificial insemination (TAI) and on evaluating the effect of the day of hCG administration (day 4 or 5 post TAI) on pregnancy rates in repeat breeder cows according to their responses to hCG administrations. Non-pregnant cyclic lactating Holstein dairy cows with more than three services despite no clinical reproductive abnormalities were enrolled in the study. All cows (n = 192) received the Ovsynch protocol (GnRH-7d-PGF(2 alpha)-56h-GnRH-16/18h-TAI) and hCG administration (1500 IU, i.m.) was performed in group hCG4 (n = 64) on day 4 and in group hCG5 (n = 68) on day 5 post TAI. The control group (CON, n = 60) did not receive any hCG treatment. The responses (ovulation rate) to hCG (similar to 64%) were similar on days 4 and 5 post TAI. Pregnancy per AI (P/AI) at 31 days was similar among the groups (48.3% in CON, 48.4% in hCG4, and 42.6% in hCG5). Regardless of the day of the treatment (hCG4 + hCG5), the cows had an ovulatory response to hCG (54.1%), and a greater P/AI (P = 0.007) at 31 days than those without a response (29.8%). The administration of hCG on either day 4 or 5 post TAI did not increase overall pregnancy rates, however, the ovulatory response to the post TAI hCG administration on day 4 improved fertility in repeat breeder cows. Further studies are needed with a larger number of animals to reveal this potentiallly beneficial effect.