Investigation of factors affecting pregnancy rate after embryo transfer in the dromedary camel

2002 ◽  
Vol 14 (2) ◽  
pp. 109 ◽  
Author(s):  
Julian A. Skidmore ◽  
M. Billah ◽  
W. R. Allen
Keyword(s):  
Pregnancy Rate ◽  
Prostaglandin F2α ◽  
Sampling Period ◽  
Dromedary Camel ◽  
Gnrh Analogue ◽  
Serum Progesterone ◽  
Factors Affecting ◽  
Flunixin Meglumine ◽  
Gonadotrophin Releasing Hormone ◽  
Serial Samples

The uteri of 36 adult dromedary camels were flushed non-surgically three times each with 90–120 mL of embryo flushing medium 7 days after ovulation. A total of 242 embryos were recovered, of which 139 were transferred non-surgically to recipient camels that were either at different levels of synchrony with respect to the Day 7 donor (+1 to –3 days; n = 58), or were at Day 6 after ovulation, but received one of the following treatments: (i) none (controls, n = 15); (ii) 150 mg progesterone-in-oil injected intramuscularly once daily during Days 5–20 after ovulation inclusive (n = 16); (iii) 500 mg flunixin meglumine given intravenously 15 min before transfer of the embryo (n = 6); (iv) 20 μg of the gonadotrophin-releasing hormone (GnRH) analogue buserelin given on Day 5 after ovulation (n = 12); or (v) the embryo was cooled to 4˚C and held at this temperature in an insulated container for 24 h before being transferred (n = 32). Jugular vein blood samples, taken daily from all the recipient camels during Days 0–20 after ovulation, were assayed for progesterone concentration and closely timed serial samples taken from the camels receiving flunixin meglumine or GnRH were assayed for 13,14-dihydro-15-keto prostaglandin F2α (PGFM) or oestradiol concentrations. The pregnancy rate increased to a maximum of 67% when ovulation in the recipient was negatively synchronized to have occurred 1 day behind that in the donor, and it fell dramatically when the level of asynchrony between recipient and donor increased to +1 (9%) or –3 (10%) days. It was not improved by daily injections of progesterone (44%), flunixin meglumine given before transfer (16%), or GnRH given on Day 5 (33%). Of the 32 embryos that were cooled to 4˚C before being transferred to Day 6 recipients, 20 resulted in pregnancies (63%) to give a success rate similar to that attained with the control fresh embryos (67%). Serum progesterone concentrations in the recipients increased to a mean ± SEM of 2.6 ± 0.8 ng mL–1 by Day 8 after ovulation and, in those that were pregnant, levels remained elevated at 3–5 ng mL–1 for the remainder of the sampling period; in non-pregnant recipients the concentrations declined to <1 ng mL–1 by Day 11. Plasma PGFM concentrations in the flunixin meglumine-treated camels remained low (40–90 pg mL–1) compared with those in the untreated control camels, in which peak values of around 180 pg mL–1 were reached within 10 min after transfer after which a steady decline occurred until resting concentrations of 90–100 pg mL–1 were reached by 110 min after transfer. Treatment with GnRH on Day 5 after ovulation produced a transitory increase in serum oestradiol-17β concentrations for 24 h. However, from Day 8, oestradiol concentrations in both the GnRH-treated and the untreated camels increased steadily to reach 2.5–3.5 pg mL–1 by Day 12.

111 Use of gonadotrophin-releasing hormone (GnRH) or equine and human chorionic gonadotrophins for oestrus synchronization and their influence on embryo viability and progesterone levels on day 16 and 30 of goats receiving GnRH 5 days after intrauterine insemination or natural service

2021 ◽  
Vol 33 (2) ◽  
pp. 163
Author(s):  
F. Encinas ◽  
M. Rojas ◽  
L. Dawson ◽  
E. Loetz
Keyword(s):  
Blood Serum ◽  
Intrauterine Insemination ◽  
Prostaglandin F2α ◽  
Gnrh Analogue ◽  
Embryo Viability ◽  
Serum Progesterone ◽  
Releasing Hormone ◽  
Pregnancy Diagnosis ◽  
Gonadotrophin Releasing Hormone ◽  
Natural Service

Gonadotrophin-releasing hormone (GnRH) or equine and human chorionic gonadotrophins (eCG and hCG) were evaluated for oestrus/ovulation synchronization (E/OS), as well as the influence of GnRH 5 days post-breeding (dpb) on embryo viability (EV), and progesterone (P4) levels on Day 16 and 30 after laparoscopic AI (LAI) or natural service (NS). Fifty-four lactating/non-lactating Alpine breed goats (average of 3.82±1.2s.d. years of age) of mixed parity were E/OS during the early transitional breeding phase using 12±1 day of 300mg of P4 and 2mL of prostaglandin F2α analogue given at P4 removal. The experiment included a sub-group from a larger study in which a completely randomised design was used. The germane data were arranged as a 2×2×2 factorial. This study focused on goats receiving 120IU of eCG and 60IU of hCG (n=40), or GnRH analogue (n=14) 24h after P4 removal. At 5 dpb, 25 goats received 1mL (IM) of GnRH and the control (n=29) received 1mL of physiologic saline. Goats were time-bred 48h after P4 withdrawal by LAI (n=33) or NS (n=21). Pregnancy was diagnosed at 18 to 24, 30, and 40 dpb by non-return to oestrus, pregnancy-specific protein B, and ultrasound, respectively. EV was evaluated as the difference between pregnancy diagnosis results. Blood serum P4 was evaluated at 5, 16, and 30 dpb. A logistic regression model was used for statistical analysis. Pregnancy rate (PR) for LAI or NS, at 18–24, 30, and 40 days was 73 vs. 76%, 67 vs. 62%, and 64 vs. 67%, respectively (P&gt;0.72). In contrast, when GnRH was used for E/OS, the 5 dpb GnRH influenced EV at 30 days (95 vs. 81%; P=0.06) but not at 40 days (89 vs. 86%; P&gt;0.35), compared with placebo. Similarly, with the exception of PR at 40 days (43 vs. 72%; P=0.05), for the GnRH and eCG/hCG E/OS groups, respectively, PR was not affected (P&gt;0.12) by either E/OS or GnRH 5 dpb or their interaction (P&gt;0.35) at any pregnancy diagnosis (i.e. 18–24, 30, or 40 dpb). Likewise, levels of P4 at 5, 16, and 30 dpb did not affect PR at 18–24, 30, and 40 dpb (P&gt;0.92, 0.71, and 0.11). As shown in Table 1, the level of P4 was not influenced for goats receiving GnRH or placebo at 5, 16, or 30 dpb. The baseline mean P4 blood serum level for goats receiving GnRH 5 dpb differed at 16 but not at 30 dpb (P&lt;0.001). Table 1 Blood serum progesterone (P4, ng mL−1) in response to gonadotrophin-releasing hormone (GnRH) or placebo given 5 days post-breeding Sampling day GnRH Placebo P &gt;1 Mean ±SE Mean ±SE 5 (baseline) 6.2a 0.83 5.7a 0.72 0.66 16 11.7b 1.11 11.0b 1.05 0.65 30 6.2a 0.89 7.6c 0.84 0.26 a–cMean values with different superscripts within a column signify statistical difference for GnRH (P&lt;0.001) and placebo (P&lt;0.02). 1Probability for mean differences in the same row.

scholarly journals The Effect of A PRID®Delta-Based Estrus Synchronization Protocol On Pregnancy Rates In Cows With No Estrus Symptoms

2022 ◽  
Author(s):  
Murat Can Demir ◽  
Cihan Kaçar ◽  
Umut Çağın Arı ◽  
Semra Kaya ◽  
Oğuz Merhan ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Artificial Insemination ◽  
Prostaglandin F2α ◽  
Pregnancy Rates ◽  
Dominant Follicle ◽  
Serum Progesterone ◽  
Blood Samples ◽  
Follicle Diameter ◽  
Follicle Size ◽  
Equine Chorionic Gonadotropin

Abstract The present study aimed to determine the effects of progesterone-based gonadotropin-releasing hormone (GnRH), prostaglandin F2α (PGF2α), and equine chorionic gonadotropin (eCG) injections on progesterone profiles and pregnancy rates in cows with no estrus symptoms within 60 days after parturition. A total of 80 cows were included in the study. All animals had the progesterone-releasing device PRID®Delta placed intravaginally for nine days with an injection of GnRH. On the eighth day, PGF2α was injected, and PRID®Delta was removed from the vagina on day nine. Artificial insemination was carried out 60 hours after PRID®Delta removal. In half of the animals (n = 40), 600 IU of eCG was injected when PRID®Delta was removed on the ninth day before artificial insemination 60 hours later. Blood samples were taken from the tail vein on days 0 and 8 to determine progesterone levels. The pregnancy rate in the group that received eCG was 37.5%, while it was 27.5% in those that did not (P = 0.4). While the dominant follicle diameter was 15.5 mm in cows injected with eCG during timed artificial insemination, the follicle diameter was 12.4 mm in cows with no eCG injection (P <0.001). There were no differences in serum progesterone values in blood samples taken until the time of artificial insemination. However, progesterone values in the blood taken during artificial insemination were 0.94 ng/ml in the eCG- group and 0.72 ng/ml in the eCG+ group (P <0.05). As a result, it was determined that eCG injections, in addition to progesterone-based GnRH and PGF2α applications, increased the pregnancy rates in cows without symptoms of estrus. The dominant follicle diameter was larger in cows treated with eCG during artificial insemination; however, follicle size did not increase the pregnancy rate.

17 PREGNANCY RATE OBTAINED WITH THE REUTILIZATION OF INTRAVAGINAL DEVICE DICO AFTER 6 DAYS OF TREATMENT FOR ESTRUS SYNCHRONIZATION IN SHEEP

2011 ◽  
Vol 23 (1) ◽  
pp. 115
Author(s):  
P. C. dos Santos-Neto ◽  
C. García-Pintos ◽  
A. Menchaca
Keyword(s):  
Pregnancy Rate ◽  
Body Condition Score ◽  
Intrauterine Insemination ◽  
Prostaglandin F2α ◽  
Follicular Development ◽  
Device Removal ◽  
Fertility Rates ◽  
Short Term ◽  
Serum Progesterone ◽  
Intravaginal Device

The new intravaginal device DICO (Dispositivo Intravaginal Caprino Ovino, 0.3 mg progesterone, Syntex, Buenos Aires, Argentina) is effective in controlling serum progesterone concentrations, follicular development and time of ovulation in sheep, even in its second use after 6 days of treatment (Vilariño et al. 2010 Small Rumin. Res. 91, 219–224). The pregnancy rate obtained with DICO in its first use is similar to that obtained with CIDR-G (Pfizer, New York, NY, USA) (abstract of García-Pintos et al. in this issue). However, pregnancy rate with the reutilisation of DICO has not been evaluated yet. The aim of this study was to determine fertility rates in ewes synchronized with a reused DICO in comparison with a reused CIDR-G. The experiment was carried out on 314 Corriedale multiparous ewes during breeding season (March, 33°S, Uruguay), with a body condition score of 3.0 ± 0.1 (scale 0–5). Ewes received a short-term-protocol using DICO (n = 139) or CIDR-G (n = 175) during 6 days, previously used for 6 days. One dose of prostaglandin F2α analogue (125 μg cloprostenol, Ciclase DL, Syntex) and 300 IU eCG (Novormon, Syntex) were given at the time of device removal. Cervical insemination (200 million spermatozoa) or laparoscopic intrauterine insemination (100 million spermatozoa) was performed with fresh semen at fixed-time 48 or 54 h from device removal, respectively. Pregnancy diagnosis was done by transrectal ultrasonography (5 MHz, Well D, Beijing, China) 40 days after insemination. Pregnancy rate was analysed by logistic regression, and number of fetus/pregnant ewes and fetus/inseminated ewes was analysed by Poisson regression. No differences were found between reused DICO and CIDR-G devices (Table 1). Overall, pregnancy rate was affected by the method of insemination (P ≤ 0.05), being lower for cervical (37.0%; 57/154) than intrauterine insemination (55.0%; 88/160). In conclusion, the reutilization of DICO devices in the short-term protocol (6 days of treatment) allows similar fertility rates compared to re-used CIDR-G devices, by both cervical and intrauterine insemination. Table 1.Fertility rate obtained with the reutilisation of DICO and CIDR in short-term protocol (6 days of treatment) in sheep

7 COMPARISON OF TIMED ARTIFICIAL INSEMINATION PROTOCOLS USING PROSTAGLANDIN F2α+ESTRADIOL OR PROSTAGLANDIN F2α+ESTRADIOL+GONADOTROPIN-RELEASING HORMONE IN DAIRY COWS

2012 ◽  
Vol 24 (1) ◽  
pp. 115
Author(s):  
J. K. Jeong ◽  
H. G. Kang ◽  
I. H. Kim
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Artificial Insemination ◽  
Prostaglandin F2α ◽  
Pregnancy Rates ◽  
Gnrh Analogue ◽  
Chi Square ◽  
Array Transducer ◽  
Chi Square Test ◽  
Timed Artificial Insemination

This study compared pregnancy rates following 2 timed artificial insemination (TAI) protocols using PGF2α + oestradiol or PGF2α + oestradiol + GnRH in dairy cows. Four hundred fifty-five Holstein dairy cows, 2.2 ± 0.1 in parity, 148.3 ± 3.6 days in milk, with corpus luteum of greater than 20 mm diameter confirmed by ultrasonography (Tringa Linear with 5.0 MHz array transducer; Esaote Pie Medical, Maastricht, the Netherlands) were randomly divided into two treatments: an injection of 500 μg of cloprostenol, PGF2α analogue (Iliren cycle BP®, Intervet International GmbH, Unterschleissheim, Germany) and an injection of 2 mg of oestradiol benzoate (EB, SY Esrone, Samyang, Seoul, Korea) 36 h later (PGF2α + EB group, n = 257), or an injection of 500 μg of cloprostenol, an injection of 2 mg of EB 36 h later and an additional injection of 100 μg of gonadorelin, GnRH analogue (Godorel, Uni-Biotech Co., Ltd., Korea) 24 h later (PGF2α + EB + GnRH group, n = 198). All cows in the two groups received TAI 24 h after the EB injection. Pregnancy was determined at 40 to 50 days after TAI by using both ultrasonography and rectal palpation. Pregnancy rates between the PGF2α + EB and PGF2α + EB + GnRH groups were compared by the chi-square test using the SAS program (version 9.1: SAS Institute Inc., Cary, NC, USA). Pregnancy rate following TAI did not differ between the PGF2α + EB (32.7%) and PGF2α + EB + GnRH groups (34.9%; P > 0.05). In conclusion, addition of GnRH for TAI protocol using PGF2α + oestradiol did not improve pregnancy rate in dairy cows.

121 Comparing Two Superstimulation Protocols Prior to Ovum Pick-Up in Dromedary Camel

2018 ◽  
Vol 30 (1) ◽  
pp. 200
Author(s):  
T. Ararooti ◽  
A. Niasari-Naslaji ◽  
K. Razavi
Keyword(s):  
Single Dose ◽  
Prostaglandin F2α ◽  
Gonadotropin Releasing Hormone ◽  
Dromedary Camel ◽  
Gnrh Analogue ◽  
Follicular Waves ◽  
Follicle Diameter ◽  
Group 2 ◽  
Good Number ◽  
Group 1

The objective of this study was to investigate different superstimulation protocol before oum pick-up (OPU) to increase the number of follicles suitable for puncture in dromedary camel. Follicular waves were synchronized using two intramuscular administrations of gonadotropin-releasing hormone (GnRH) analogue (Alarelin, 25 µg, Vetaroline®, Aburaihan, Iran) 12 to 15 days apart. Two days after the second GnRH (Day 0 of experiment), donors were assigned into 2 groups (n = 6 in each group) receiving different amounts of eCG (Pregnecol®, Bioniche, Canada; intramuscular) and FSH (Folltropin-V®, Bioniche, Canada; intramuscular). Groups 1 and 2 received the respective amounts of eCG (3000 and 2000 IU) and FSH (200 and 160 mg). The eCG was administered as a single dose at the start of superstimulation and FSH was delivered twice daily in decreasing doses (group 1: 40, 30, 20, 10 mg; group 2: 30, 20, 20, 10 mg) between Days 0 and 3. On Day 4 of superstimulation, camel received 2 doses of prostaglandin F2α analogue (25 mg of dinoprost tromethamine; Lutalyse®, Pfizer, Belgium; intramuscular), 12 h apart and were examined by ultrasonography in the morning to record ovarian follicles (≥4 mm in diameter). Data were analysed using GLM procedure followed by Tukey in SAS (SAS Institute Inc., Cary, NC, USA). Data were presented as mean ± SEM. On Day 4 of superstimulation, the average follicle diameter was similar in group 1 (6.4 ± 0.16 mm) and group 2 (7.4 ± 0.33 mm; P > 0.05). The total number of follicles were different between group 1 (15.5 ± 1.75) and group 2 (4.7 ± 0.71; P < 0.001). Total number of follicles ≤6 was significantly greater in group 1 (6.2 ± 0.95) than in group 2 (1.2 ± 0.60; P < 0.05). Total number of follicles >6 mm in group 1 (9.3 ± 1.20) was greater than in group 2 (3.5 ± 0.76; P < 0.01). In conclusion, superstimulation with eCG (3000 IU) and FSH (200 mg) could provide a relatively good number of follicles for aspiration in OPU program of dromedary camel.

Embryo transfer in the dromedary camel (Camelus dromedarius) using asynchronous, meclofenamic acid-treated recipients

2005 ◽  
Vol 17 (4) ◽  
pp. 417 ◽  
Author(s):  
Julian A. Skidmore ◽  
M. Billah
Keyword(s):  
Embryo Transfer ◽  
Fetal Mortality ◽  
Control Group ◽  
Dromedary Camel ◽  
Serum Samples ◽  
Serum Progesterone ◽  
Meclofenamic Acid ◽  
Gonadotrophin Releasing Hormone ◽  
Baseline Values ◽  
Acid Administration

A total of 40 (Day 7) embryos were recovered from the uteri of 10 superovulated camels. Recipient camels (n = 30) were prepared by injection with 20 μg of the gonadotrophin-releasing hormone analogue buserelin (i.v.) to induce ovulation and then treatment with 1 g meclofenamic acid (a prostaglandin synthetase inhibitor), orally, once on Day 7 and twice daily on Days 8 and 9 after ovulation and thereafter at a dose of 1 g day−1 until 8 days after embryo transfer. Embryos were transferred into recipients on Day 8 (n = 10), Day 10 (n = 10) or Day 12 (n = 10) after ovulation and another 10 embryos were transferred into untreated recipients on Day 8 after ovulation as controls. In addition, serum samples from all recipient camels were recovered daily throughout the period of meclofenamic acid administration and for a further 7 days after treatment had ceased and were assayed for progesterone concentrations. Results showed that whereas only one of 10 of the control group of recipients (10%) was diagnosed pregnant, a total of eight of 10 Day 8 (80%), six of 10 Day 10 (60%) and seven of 10 Day 12 (70%) recipients were diagnosed pregnant by ultrasonography 12 days after the embryo had been transferred. Subsequently, however, four pregnancies were lost when the conceptus was aged between 22 and 60 days, but this is not considered above the early fetal mortality rate expected in camels after natural mating or after transferring camel embryos to untreated recipients. Serum progesterone concentrations remained elevated, above 2 ng mL−1, throughout the period of meclofenamic acid administration in all recipient camels; thereafter, concentrations remained above 2 ng mL−1 in pregnant animals, whereas in non-pregnant camels concentrations had declined to baseline values (<1 ng mL−1) within 3 days of the end of the treatment period. In conclusion, treatment of recipient camels with meclofenamic acid reduced the need for tightly timed synchrony between donor and recipient because pregnancies were established in recipients that had ovulated as much as 5 days ahead of the donor.

110 Pregnancy rate and embryo viability in response to chorionic gonadotrophins given for oestrus induction and gonadotrophin-releasing hormone 5 days after timed laparoscope-aided insemination of lactating and non-lactating goats

2021 ◽  
Vol 33 (2) ◽  
pp. 162
Author(s):  
M. Calle ◽  
L. Dawson ◽  
M. Rojas ◽  
E. Loetz
Keyword(s):  
Pregnancy Rate ◽  
Follicular Development ◽  
Specific Protein ◽  
Randomised Control Trial ◽  
Gnrh Analogue ◽  
Embryo Viability ◽  
Releasing Hormone ◽  
Lactating Goats ◽  
Gonadotrophin Releasing Hormone ◽  
The Difference

Gonadotrophins are included in oestrous/ovulation synchronization (E/OS) regimens when breeding early in the transitional phase to promote follicular development. However, the time of use has been a matter of debate. Hence, the objective of this study was to determine whether equine and human chorionic gonadotrophins (eCG and hCG, respectively) given 24h before or 24h after concurrent removal of intravaginal progestagen (P4) and prostaglandin (PGF2α) delivery influences pregnancy rate (PR) and/or embryo viability (EV). Relatedly, the influence of gonadotrophin-releasing hormone (GnRH) 5 days post-breeding (dpb) on PR and/or EV was also considered. A prospective randomised control trial was conducted using lactating and non-lactating Alpine breed goats of different parity, average±s.e. age, and bodyweight (3.7±2.6), and (52.5±7), respectively. Goats were time-bred at 48h after P4 removal by laparoscopy (LAI; n=75) or by natural service (NS; n=29) during the early transitional breeding phase in mid-September through mid-December (corresponding to 12:12h daylight/darkness). E/OS used an intravaginal device containing 300mg of P4 for 12±1d. At P4 removal, 2mL of PGF2α was administered IM. Twenty-four hours before (E) or 24h after (L) P4 removal, an IM dose of 1.5mL containing 120IU of eCG and 60IU of hCG was given. A third control (C) group (n=38) was not exposed to gonadotrophins. GnRH analogue was given (n=51) 5 days after insemination, and the remaining goats (n=53) received an IM dose of 2mL of saline solution. PR was evaluated at 18 to 24 (dpb) by non-return to oestrus (NRE), at 30 dpb by pregnancy-specific protein B (PSPB), and at 40 dpb by ultrasound imaging (UI). EV was determined from the difference between pregnancy outcomes for NRE and PSPB, and PSPB and UI. Statistical analysis (JMP/SAS vs.11; SAS Institute Inc.) were obtained using logistic regression. All concomitant variables (i.e. parity, bodyweight, days of P4 exposure, and lactation were not influenced by PR or EV; P&gt;0.07). The overall PR was 71% for LAI and 69% for NS and, as shown in Table 1, was similar (P&gt;0.49) at all times (at 18 to 24, 30, and 40 dpb). Likewise, the breeding procedure did not influence the levels of EV at 30 or 40 dpb. E/OS protocol or the use of GnRH 5 dpb did not affect PR or EV at any of the time points evaluated. Table 1. Main effect mean comparisons and logistic model probabilities for pregnancy rate (PR) and embryo viability (EV) by main treatment effect Response variable (days post-breeding) Breeding procedure E/OS Protocol Gonadotrophin LAI NS P&gt; Control Early Late P&gt; GnRH Placebo P&gt; PR at 18–24 77 72 0.49 76 73 78 0.83 78 74 0.49 PR at 30 68 66 0.65 66 65 70 0.82 71 64 0.43 PR at 40 69 69 0.78 66 69 73 0.77 73 66 0.43 EV at 30 89 90 0.94 86 94 90 0.65 92 87 0.46 EV at 40 88 95 0.42 86 89 94 0.73 92 87 0.43

151 Influence of chorionic gonadotrophin, breeding procedure, and gonadotrophin-releasing hormone on pregnancy, embryo viability, and kidding rate of lactating Alpine goats time inseminated during the early transitional reproductive phase

2020 ◽  
Vol 32 (2) ◽  
pp. 202
Author(s):  
M. Calle ◽  
L. Dawson ◽  
M. Rojas ◽  
E. Loetz
Keyword(s):  
Pregnancy Rate ◽  
Chorionic Gonadotrophin ◽  
Gnrh Analogue ◽  
Embryo Viability ◽  
Response Variable ◽  
Releasing Hormone ◽  
Intramuscular Dose ◽  
Reproductive Phase ◽  
Lactating Goats ◽  
Gonadotrophin Releasing Hormone

Oestrus and ovulation synchronisation (E/OS) regimens containing equine chorionic gonadotrophin (ECG) are used for follicular stimulation during the early transitional reproductive phase and goat anestrus. However, the effects of ECG when applied at different times are unknown. Thus, the objective was to evaluate the influence of ECG, breeding procedure, and gonadotrophin-releasing hormone (GnRH) on pregnancy, embryonic viability, and kidding rate in dairy goats. We used 41 alpine goats (mean±standard deviation: 3.82±1.2 years old; 57.0±6.0kg of bodyweight; 1.75-2.25 body condition score; 195±16.7 days in milk; range of 1-4 kiddings). This study took place during the transitional phase (12h of daylight, 12h of dark) in September (35.9° N, 97.3° W) using controlled internal drug release intravaginal inserts (300mg of progestagen; P4) for 11, 12, or 13 days with a 2-mL intramuscular dose containing 10mg of dinoprost tromethamine at P4 removal. The E/OS protocols differed on the time when the 1-mL intramuscular dose of P.G. 600© (Merck Animal Health; 120 and 60IU of ECG and human chorionic gonadotrophin, respectively) was given (i.e. early=24h before P4 removal; late=24h after P4 removal), and the traditional control group did not receive P.G. 600. Time breeding, either by laparoscopic-aided insemination using frozen-thawed semen (n=28) or natural (n=13), was scheduled 48h after P4 removal. To improve embryo survival, 5 days post-breeding (dpb) 21 goats received 1mL of GnRH analogue intramuscularly as 50µgmL−1 gonadorelin diacetate tetrahydrate, and 20 control goats received 1mL of placebo intramuscularly. Pregnancy rate (PR) was evaluated at d 18-24 by non-return to oestrus, d 30 by pregnancy-specific protein B, and d 40 by ultrasound. Kidding rate was determined for females with at least one newborn. Logistic regression was used to establish statistical significance. Days of P4 exposure did not influence any response variable (P&gt;0.20). Table 1 summarises the results; age influenced all PR evaluations. The number of kiddings and administration of GnRH at 5 dpb had a significant effect on PR, whereas bodyweight, days in milk, E/OS protocol, and breeding procedure were not influential. Embryo viability and kidding rate were not influenced by any variable. In short, P.G. 600 had no bearing on any response variable analysed. Late-lactating goats can be evaluated early in the transitional breeding phase using PR at 18-24, 30, or 40 dpb. As indicated by the lack of effect on embryo viability at 30 and 40 days, the mechanism by which GnRH increases PR was not by decreasing embryo mortality. Table 1.Logistic model independent variable probabilities on response variables1 Response variable Age (years) BW Kidding DIM E/OS protocol GnRH Breeding procedure PR 18-24 d 0.02 0.65 0.15 0.52 0.37 0.21 0.30 PR 30 d 0.01 0.56 0.05 0.58 0.61 0.05 0.39 PR 40 d 0.001 0.12 0.01 0.60 0.62 0.02 0.35 EV 30 d 0.62 0.96 0.61 0.63 0.30 0.32 0.36 EV 40 d 0.44 0.90 0.26 0.36 0.46 0.17 0.40 KR 0.83 0.93 0.63 0.86 0.42 0.29 0.35 1BW=body weight; DIM=days in milk; E/OS=oestrus/ovulation synchronisation; GnRH=gonadotrophin-releasing hormone; PR=pregnancy rate; EV=embryo viability at 30 and 40 d; KR=kidding rate.

157 Effect of a slow-release gonadotrophin-releasing hormone analogue on ovarian activity and oestrous behaviour in mares

2020 ◽  
Vol 32 (2) ◽  
pp. 205
Author(s):  
M. Kaps ◽  
C. Gautier ◽  
C. Cardoso Okada ◽  
J. Kuhl ◽  
J. Aurich ◽  
...  
Keyword(s):  
Ovarian Function ◽  
Slow Release ◽  
Treatment Time ◽  
Prostaglandin F2α ◽  
Control Group ◽  
Ovarian Activity ◽  
Gnrh Analogue ◽  
Dependent Manner ◽  
Releasing Hormone ◽  
Gonadotrophin Releasing Hormone

Oestrus behaviour in mares can contribute to problems in their handleability and reduced performance in equestrian sports. Therefore, methods of transient suppression of oestrous cyclicity in mares are of interest. The aim of our study was to determine whether treatment of mares with slow-release implants containing the gonadotrophin-releasing hormone (GnRH) analogue deslorelin downregulates pituitary GnRH receptors and reduces ovarian function and oestrous behaviour. Shetland mares (age=11.0±1.4 years; bodyweight=185.5±7kg) were oestrous synchronised with two injections of the prostaglandin F2α analogue luprostiol (3.725mg) at an interval of 12 days. One day after the second injection (Day 0), mares were randomly assigned to three groups: slow-release implant with 9.4mg of deslorelin (Suprelorin, Virbac; group D1; n=6), implant with 4.7mg of deslorelin (group D2; n=5), and intramuscular injection of 1.25mg of short-acting deslorelin (control, group C; n=5). Collection of blood samples for analysis of progesterone, LH, and anti-Müllerian hormone (AMH) using established and validated enzyme immunoassays (Scarlet et al. 2018 Theriogenology 117, 72-77), testing for oestrus-like behaviour with a Shetland stallion, and ultrasonography of the genital tract were performed at 2-day intervals until Day 10 after treatment and at 5-day intervals from there. On Days 10 and 45 after treatment, LH stimulation tests with the GnRH agonist buserelin (4µg IV) were performed. Data were normally distributed; differences among groups were analysed using analysis of variance and subsequent Tukey test. Values are means±s.e.m. In all mares without a corpus luteum on Day 0 (progesterone &lt;1ngmL−1; one mare in group D1 and two in group C), ovulation was detected within 9 days after deslorelin treatment. These ovulations were classified as deslorelin induced, whereas ovulations after Day 10 were classified as spontaneous ovulations. The mean interval from deslorelin until the first spontaneous ovulation was 62.0±8.6, 44.2±14.1, and 22.2±3.1 days in groups D1, D2, and C (P&lt;0.05), respectively. Subsequent oestrous cycles were regular. Oestrus-like behaviour until day 50 was reduced in groups D1 (2.0±0.9 days) and D2 (2.4±1.3 days) compared with group C (6.4±1.2 days; P&lt;0.05). Concentration of plasma LH and AMH decreased in group D1 (P&lt;0.05) but not in groups D2 and C. The GnRH stimulation test on Day 10 resulted in an increase (P&lt;0.001) in plasma LH concentration in group C but not in groups D1 and D2 (treatment×time P&lt;0.05). On Day 45, LH concentration increased in all mares in response to buserelin (NS among groups). Within 100 days of treatment, LH concentrations but not AMH concentrations in mares of group D1 returned to baseline. In conclusion, deslorelin slow-release implants transiently suppress ovarian function and oestrus behaviour in mares. Spontaneous ovulation is delayed in a dose-dependent manner. A decrease in AMH concentration suggests inhibitory effects of deslorelin on small antral follicles. Long-term effects on follicular dynamics and fertility in larger horses also need to be assessed.

7 OESTRAL RESPONSE AND FERTILITY IN DAIRY COWS TREATED WITH PROGESTERONE FOR 6 DAYS PRIOR TO OESTRUS SYNCHRONIZATION WITH PROSTAGLANDIN F2α

2014 ◽  
Vol 26 (1) ◽  
pp. 118
Author(s):  
M. Orozco ◽  
C. G. Gutierrez ◽  
R. Lopez ◽  
C. Aguilar ◽  
C. Roque ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Prostaglandin F2α ◽  
Control Group ◽  
Serum Progesterone ◽  
Progesterone Treatment ◽  
The Individual ◽  
Rectal Palpation ◽  
And Control ◽  
Intravaginal Device

The present study tested whether the increase in serum progesterone concentrations for 6 days before oestrus synchronization with prostaglandin F2α (PGF2) increases oestral response, pregnancy rate, and reduces the incidence of twin births in dairy cattle. Seven hundred and eighty-three first-service dairy cows were synchronized with 2 injections of PGF2 14 days apart, starting on Day 35 postpartum. Six days before the second PGF2 injection, cows were assigned to 2 groups: P4 and control. The P4 group (n = 387) received a progesterone-releasing intravaginal device and an intramuscular injection of 500 mg of progesterone. The control group (n = 396) did not receive the progesterone-releasing intravaginal device or progesterone injection. Cows were inseminated 12 h after exhibiting oestrus. Pregnancy diagnosis was performed 40 and 45 days after insemination by rectal palpation and the cumulative pregnancy rate on Day 90 postpartum was determined retrospectively through the individual records. The response to the progesterone treatment varied according to the parity of the cows (P < 0.05). Thus, progesterone administration improved the percentage of cows detected in oestrus in multiparous [192/255 (75.2%) v. 161/267 (60.2%)] but not in primiparous [93/132 (70.4%) v. 90/129 (69.7%)] cows. Progesterone treatment increased pregnancy rate in multiparous [53/192 (27.6%) v. 27/161 (16.7%)] but not in primiparous cows [25/93 (26.8%) v. 29/90 (32.2%)]. Likewise, progesterone administration increased the cumulative percentage of pregnant cows on day 90 postpartum in multiparous [149/255 (58.4%) v. 129/267 (48.3%)] but not in primiparous cows [77/132 (58.3%) v. 82/129 (63.5%)]. The incidence of twin births was lower (P = 0.07) in cows treated with progesterone [1/74 (1%)] than in the control group [4/53 (7%)]. It is concluded that progesterone administration before oestrus synchronization with PGF2 in first service dairy cows improves oestral response, increases pregnancy rate, and percentage of pregnant animals on Day 90 postpartum in multiparous cows, but not in primiparous cows, and decreases the incidence of twin births. This research was supported by PAPIIT-UNAM research grant (IN219811-3).

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