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    Effect of delaying the time of insemination with sex-sorted semen on pregnancy rate in Holstein heifers
    (Blackwell Publishing Ltd, 2020) Guner, Baris; Erturk, Melih; Yilmazbas-Mecitoglu, Gulnaz; Keskin, Abdulkadir; Karakaya-Bilen, Ebru; Cakircali, Rabia; Serim, Enes
    The objective of the study was to evaluate the interval from onset of oestrus to time of artificial insemination (AI) to obtain the optimum pregnancy rate with sex-sorted semen in Holstein heifers. Heifers in oestrus were detected and inseminated only by using heat–rumination neck collar comprised electronic identification tag at the age of 13–14 months. Heifers (n = 283) were randomly assigned to one of three groups according to the timing of insemination at 12–16 hr (G1, n = 97), at 16.1–20 hr (G2, n = 94) and at 20.1–24 hr (G3, n = 92) after reaching the activity threshold. The mean duration of oestrus was 18.6 ± 0.1 hr, and mean peak activity was found at 7.5 ± 0.1 hr after activity threshold. The mean interval from activity threshold to ovulation was 29.4 ± 0.4 hr. The overall pregnancy per AI (P/AI) was 53.0% at 29–35 days and 50.9% at 60–66 days after AI. There was a significant reduction between G1 (13.8 ± 1.4 hr) and G3 (7.9 ± 1.4 hr) related to the intervals from AI to ovulation time. Sex-sorted semen resulted in significantly higher P/AI at 29–35 days when heifers inseminated in G3 (60.9%) after oestrus than those inseminated in G1 (49.5%) and G2 (48.9%). In terms of fertility, when the temperature–humidity index (THI) was below the threshold value (THI ?65) at the time of AI, there was a tendency (?65; 57.2% vs. > 65; 47.1%) for high pregnancy rate. There was no effect of sire on P/AI. In addition, the interaction of the technician with the time of AI was found significant, and three-way interaction of technician, sire and time of AI was tended to be significant on pregnancy rate. Thus, in addition to delaying the time of insemination (between 20.1 and 24 hr) after oestrous detection, THI and experienced technician were also found to be critical factors in increasing fertility with the use of sex-sorted semen in Holstein heifers. © 2020 Wiley-VCH GmbH
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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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    Effects of daily propylene glycol drenching during the Ovsynch protocol on fertility and metabolic parameters in lactating dairy cows
    (Wiley, 2023) Cakircali, Rabia; Karakaya-Bilen, Ebru; Guner, Baris; Mecitoglu, Zafer; Ortac, Cihan Tolga; Keskin, Abdulkadir; Orman, Abdulkadir
    Negative energy balance (NEB) caused by restricted feed intake leads to body condition loss (BCS), increased metabolic stress and reduced fertility in dairy cows. Propylene glycol (PG) is a precursor of ruminal propionate for gluconeogenesis used to increase metabolic adaptation to the early postpartum period. The aim of this study was to determine the effects of daily drenching of PG during the fixed-time artificial insemination (FTAI) protocol on beta-hydroxybutyric acid (BHBA), glucose, adiponectin, insulin-like growth factor-1 (IGF1) concentrations, follicle size and pregnancy rate in dairy cows. Cows (n = 148) were randomly divided into two groups and received either 300 mL of PG (PG-OVS, n = 76) or 300 mL of water (CON- -OVS, n = 72) each day of the Ovsynch protocol (GnRH-7 days-PGF2a-56 hours-GnRH-16-18-hour FTAI) between days 57 +/- 3 to 67 +/- 3 postpartum for the first service. Body condition scores (14 days before expected calving, at calving, on days 21 and 42 postpartum) were recorded. Blood samples were collected days 7 +/- 3, 21 +/- 3 postpartum, at the beginning of the Ovsynch (days 57 +/- 3) and at the time of FTAI (days 67 +/- 3) for measurements of BHBA, glucose, adiponectin and IGF1 concentrations. Ultrasonographic examinations were done to measure follicle size at the beginning of Ovsynch and FTAI and to determine pregnancy on days 30 and 60 following FTAI. There were no differences (p >.05) in glucose, adiponectin and IGF1 concentrations between the groups during the study. Although there was no difference ( p >.05) in BHBA concentrations on postpartum day 7 +/- 3, 21 +/- 3 and 57 +/- 3 between the groups, BHBA concentrations at the time of insemination was lower (p <.05) in the PG-OVS group (0.72 +/- 0.03 mmol/L) than in the CON-OVS group (0.81 +/- 0.03 mmol/L). Follicle sizes at the beginning of Ovsynch (PG-OVS, 14.5 +/- 0.48 mm; CON-OVS, 14.3 +/- 0.59 mm) and FTAI (PG-OVS, 17.8 +/- 0.52 mm; CON-OVS, 17.7 +/- 0.42 mm) were not different ( p <.05). Pregnancy rate of the cows in the PG-OVS group (46.1%, 35/76) was higher (p =.05) than in the CON-OVS group (30.6%, 22/72) on day 30 following FTAI. In conclusion, decreasing serum BHBA concentrations at the time of FTAI by means of daily drenching of PG during the Ovsynch protocol, increased the pregnancy rate at first service in lactating dairy cows. On the other hand, blood glucose was not related with pregnancy rates in our study, probably as a result of our sampling time and more rapid fluctuations of blood glucose concentrations when compared to BHBA.
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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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    Perioperative Change of High-Sensitive Cardiac Troponin I Concentration in Cats According to Three Different Anaesthesia Protocols
    (Wiley, 2024) Safak, Tarik; Yilmaz-Koc, Oznur; Karakaya-Bilen, Ebru
    Background: Cardiac troponin I, a particular biomarker, is released into the bloodstream in response to myocardial injury. Background: To evaluate perioperative changes in high-sensitivity cardiac troponin I (hs-cTnI) concentration during ovariohysterectomy in cats undergoing three different anaesthesia protocols. Methods: Twenty-one female mixed-breed cats owned by clients aged (2.2 +/- 0.7 years) and weight (3.2 +/- 0.5 kg) were included in our study. The cats were divided into three groups: propofol-isoflurane (PI) group (n = 7), xylazine-ketamine (XK) group (n = 7) and xylazine-isoflurane (XI) group (n = 7). After pre-anaesthetic propofol (6 mg/kg IV) was administered to cats in Group PI, a mask was placed, and anaesthesia was maintained with 3.0% isoflurane in oxygen. Cats in Group XK underwent general anesthetization with xylazine hydrochloride (2 mg/kg IM) and, 10 min later, ketamine hydrochloride (10 mg/kg IM). Cats in Group XI were administered xylazine hydrochloride (2 mg/kg IM), and then anaesthesia (3.0% isoflurane and oxygen) was continued with a mask. Blood samples were collected from all cats; preoperatively and postoperatively at 0 and 12 h (Pre-, Post-0 h and Post-12 h, respectively). Serum hs-cTnI concentrations were measured with the Advia Centaur TnI-Ultra. Results: In all 21 cats, hs-cTnI concentration increased at Post-0 h and 12 h measurement points compared to Pre-. In the XK group, hs-cTnI concentrations exhibited a significant increase at the Post-0 h (51.30 ng/L) and Post-12 h (157.70 ng/L) time points compared to Pre- (6.70 ng/L) (p < 0.05). Conclusions: The XK group increased the concentration of hs-cTnI more than other protocols. In the PI group, the increase in hs-cTnI concentrations at Post-0 and 12 h increased less than the other two groups (p < 0.05). The PI group was found to induce less myocardial damage.
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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.