122 Effect of gonadotropin-releasing hormone plus 7-day progesterone (CIDR) with or without eCG on follicular dynamics, estrus response, and pregnancy rate in anestrous Beetal goats during nonbreeding season under subtropical conditions

Oestrus induction is a challenging task during the nonbreeding season in goats. Therefore, our objective was to evaluate the efficacy of gonadotropin-releasing hormone (GnRH) plus a 7-day CIDR-based protocol with or without eCG for the induction of oestrus and fertility in acyclic Beetal goats during the nonbreeding season under subtropical conditions. Based on the absence of corpus luteum via ultrasonography, goats (n=56; mean weight=32.8±0.5 kg; body condition scre=2.5±0.1) were inserted with a CIDR (300mg progesterone) along with GnRH (Day 0), and randomly treated either with eCG (400 IU; n=35) or without eCG (control; n=21) on Day 7. The CIDR was removed on Day 7 and all does were administered single dose of prostaglandin F2α (75µg cloprostenol; Fatro, Italy). Following CIDR insertion, ovarian follicular dynamics was monitored daily through a 7.5-MHz transrectal transducer (Honda HS 1500, Japan) until ovulation in a subset of eCG (n=11) and control goats (n=10). Oestrus was detected at every 12h after CIDR removal with aproned bucks and does were bred naturally. Pregnancy was detected 25 days after breeding by transrectal ultrasound. Data were analysed by t-test, ANOVA, and Chi-squared test using SPSS (version 20.0, SPSS Inc., Chicago, IL, USA). Oestrus occurred more often following CIDR removal in eCG v. control goats (94v. 57%; P<0.05). Similarly, onset of oestrus was earlier (36.0±2.1v. 54.2±4.7 h; P<0.05) and the duration of oestrus was longer in eCG v. control goats (i.e. 30.2±1.3v. 22.1±2.3 h; P<0.05). However, diameter of preovulatory follicles and interval to ovulation after CIDR removal were similar between eCG and control goats (P>0.05). In contrast, growth rate of preovulatory follicle after CIDR removal until ovulation in eCG goats was greater, and ovulation rate was higher than control goats (0.7±0.1v. 0.3±0.1 mm/day; 2.2±0.2v. 1.4±0.2, respectively; P<0.05). In eCG goats, the dominant follicle grew rapidly between Days 8 to 9 (P<0.05), whereas within control goats the dominant follicle grew at consistent rate (P>0.05). After CIDR removal, percentage of ovulating goats in eCG was higher as compared to the control group (100v. 44%; P<0.05). Within control goats, size of the dominant follicle in ovulatory goats was greater at the time of CIDR removal than anovulatory goats (5.7±0.3v. 5.0±0.15 mm; P<0.05), whereas wave emergence tended to be earlier after CIDR insertion in anovulatory goats (4.2±1v. 2.6±0.4 days; P=0.09). Pregnancy rate 25 days postbreeding did not differ between eCG and control goats [i.e. 49% (16/33) v. 25% (3/12); odds ratio 2.9/1; P>0.05]. In conclusion, the eCG protocol resulted in higher oestrus response, ovulation rate, and 3 times higher pregnancy rate in anestrous goats during the nonbreeding season.

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252 EFFECT OF SUPERSTIMULATORY TREATMENT TO DONOR COWS IN OXYGEN CONSUMPTION OF MATURED OOCYTES

Reproduction Fertility and Development ◽

10.1071/rdv25n1ab252 ◽

2013 ◽

Vol 25 (1) ◽

pp. 273

Author(s):

K. Imai ◽

S. Sugimura ◽

M. Ohtake ◽

Y. Aikawa ◽

Y. Inaba ◽

...

Keyword(s):

Oxygen Consumption ◽

Prostaglandin F2α ◽

Gonadotropin Releasing Hormone ◽

Oestrous Cycle ◽

Control Group ◽

Releasing Hormone ◽

And Control ◽

Bovine Oocytes

We previously reported that follicular wave synchronization and follicular growth treatment (FGT) before ovum pick-up (OPU) were effective in improving oocyte competence, which was associated with an increase in related embryos obtained by somatic cell nuclear transfer (Sugimura et al. 2012 Cell. Reprogram. 14, 29–37). However, oxygen consumption in oocytes remained unknown. The present study was designed to examine the differences in oxygen consumption between bovine oocytes obtained by OPU with or without FGT after in vitro maturation. Holstein dry cows (n = 8) were reared under the same feeding and environmental conditions. Two OPU sessions were conducted in each cow to collect immature oocytes, as described by Sugimura et al. (2012). The first OPU session (OPU group) was performed in cows on arbitrary days of the oestrous cycle, using a 7.5-MHz linear transducer with the needle connected to an ultrasound scanner. Follicles larger than 8 mm in diameter were then aspirated and a controlled internal drug release device (CIDR) was inserted on Day 5 (the day of the first OPU session = Day 0). Then 30 Armour units (AU) of FSH (Antrin, Kyoritsu Seiyaku, Tokyo, Japan) was administrated to cows twice a day from Day 7 to 10 in decreasing doses (6, 6, 4, 4, 3, 3, 2, 2 AU day–1). Cloprostenol (prostaglandin F2α; 0.75 mg) was administered in the morning of Day 9. The second OPU session (FGT-OPU group) was performed 48 h after prostaglandin F2α administration (Day 11), and only follicles larger than 5 mm in diameter were aspirated. The CIDR was removed from the cows just before OPU. Collected cumulus–oocyte complexes in the OPU and FGT-OPU groups were matured in vitro as described by Imai et al. [2006 J. Reprod. Dev. 52(Suppl.), S19–S29]. To collect in vivo-matured oocytes (control group), the CIDR was inserted into the cows on arbitrary days of the oestrous cycle (= Day 0), and oestradiol benzoate (0.8 mg) was administered on Day 1. The cows received the FGT treatment (as described above) from Day 6 to 10; however, the CIDR was removed in the evening of Day 8. Buserelin (gonadotropin-releasing hormone; 200 µg) was then administrated in the morning of Day 10, and OPU was performed at 24 h after gonadotropin-releasing hormone administration (Day 11). Oxygen consumption of matured oocytes was measured noninvasively with a scanning electron microscopy system (HV-405SP; Hokuto Denko Co., Tokyo, Japan). Data were analysed by ANOVA followed by a Tukey-Kramer test. There was no difference in the mean oxygen consumption between the FGT-OPU group (0.34 ± 0.02 × 10–14 mol–1, mean ± SEM) and control group (0.40 ± 0.01 × 10–14 mol–1). However, oxygen consumption in the FGT-OPU and control groups was significantly lower (P < 0.01) than that in the OPU group (0.50 ± 0.02 × 10–14 mol–1). These results revealed significantly lower oxygen consumption in OPU-derived in vitro-matured bovine oocytes after FGT treatment compared with those obtained without FGT treatment. Oxygen consumption of oocytes obtained from FGT-OPU was similar to that of in vivo-matured oocytes, which may reflect their cytoplasmic maturation status with high developmental competence.

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12 EFFECT OF HUMAN CHORIONIC GONADOTROPIN (hCG) ADMINISTRATION ON DAY 2 OR DAY 5 AFTER OESTRUS ON PREGNANCY RATE IN HIGH-YIELDING DAIRY COWS

Reproduction Fertility and Development ◽

10.1071/rdv27n1ab12 ◽

2015 ◽

Vol 27 (1) ◽

pp. 98 ◽

Cited By ~ 1

Author(s):

J. M. Sanchez ◽

V. Maillo ◽

L. Molina ◽

C. C. Perez-Marin ◽

P. Lonergan ◽

...

Keyword(s):

Dairy Cows ◽

Pregnancy Rate ◽

Body Condition Score ◽

Significant Proportion ◽

Prostaglandin F2α ◽

Gonadotropin Releasing Hormone ◽

Pregnancy Rates ◽

Holstein Cows ◽

Control Group ◽

Releasing Hormone

In cattle, ~40% of embryonic loss occurs in the period from Day 8 to Day 16 of pregnancy. A significant proportion of embryo loss may be due to inadequate circulating progesterone (P4) concentrations. Low P4 concentrations have also been implicated as a causative factor in the low pregnancy rates (PR) observed in high-yielding dairy cows. Administration of hCG during the early luteal phase stimulates hypertrophy of the original corpus luteum (CL) and, depending on the day of administration, induces ovulation of the first-wave dominant follicle and formation of a functional accessory CL, which increases circulating P4 concentrations. The aim of this study was to examine whether administration of hCG on Day 2 or Day 5 after oestrus after timed AI (TAI) would lead to an increase in pregnancy rates in dairy cattle. Lactating Holstein cows (n = 194) from 12 commercial dairy herds in Southern Spain (37.8833° N, 4.7667° W) with an average milk production at 37.8 L/cow per day and typically with a PR to first AI of ~30% were randomly assigned based on their body condition score (2.65 ± 0.05; mean ± SEM), parity (2.60 ± 0.09), and days in milk (75.06 ± 0.63) to 1 of 3 treatments and administered a single intramuscular injection of 3000 IU of hCG (4 mL of Veterin Corion) either (1) on Day 2 = 36 h after TAI (n = 65; hCG2 group), (2) Day 5 = 108 h after TAI (n = 64; hCG5 group), or (3) 4 mL of saline on Day 2 = 36 h after TAI (n = 65; control group). Cows were synchronized using a 7-day Ovsynch TAI protocol that included a P4-releasing intravaginal device (PRID DELTA 1.55 g). First, gonadotropin-releasing hormone (Cystorelin 100 mg) treatment was administered at PRID insertion (Day 0) followed by 25 mg Dinoprost (prostaglandin F2α: Enzaprost T) on Day 7 at PRID withdrawal. Then, 56 h later, the second gonadotropin-releasing hormone (100 mg) treatment was administered and all cows were inseminated 16 h later. Pregnancy was diagnosed by ultrasonography 28 to 32 days after TAI. Logistic regression model and chi-squared test were used to analyse data. Pregnancy rate to AI was significantly higher in the hCG2 and hCG5 groups than in the control group (43.1 and 45.3%, v. 27.7%; P < 0.05). A treatment-by-parity interaction was observed; while pregnancy rate for primiparous cows was not affected by treatment, multiparous cows from the hCG2 group had greater pregnancies per AI than those in the control group (47.2% v. 21.1%, respectively; P < 0.05). In conclusion, these preliminary results suggest that hCG administration on Day 2 and 5 after oestrus increases PR at first postpartum AI in Holstein cows. In addition, hCG on Day 2 increases the fertility in multiparous cows.This study was funded by the Spanish Ministry of Science and Innovation (AGL2012–37510) and partially supported by Ceva Salud Animal S.A., Spain – synchronization protocol and DFV, Spain – hCG treatments.

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62 Will Gonadotropin-Releasing Hormone Treatment Hasten the Onset of Puberty in Peripubertal Heifers?

Reproduction Fertility and Development ◽

10.1071/rdv30n1ab62 ◽

2018 ◽

Vol 30 (1) ◽

pp. 170

Author(s):

N. A. Castro ◽

C. E. Leonardi ◽

E. M. Zwiefehofer ◽

J. Singh ◽

G. P. Adams

Keyword(s):

Single Point ◽

Hormone Treatment ◽

Gonadotropin Releasing Hormone ◽

Control Group ◽

Control Groups ◽

Releasing Hormone ◽

Engineering Research ◽

Follicular Wave ◽

Chi Squared ◽

And Control

Treatment with gonadotropin-releasing hormone (GnRH) has been used to induce ovulation in prepubertal heifers. The objective of this study was to evaluate whether peripubertal heifers will continue to ovulate at regular intervals (i.e. attain puberty) after GnRH treatment. Prepubertal crossbred Hereford heifers, 11.0 ± 0.5 months of age, 344 ± 26 kg of body weight, and at random stages of ovarian follicular wave status, were assigned to 2 groups (age- and weight-matched) and given GnRH (n = 24) or no treatment (Control, n = 22) on Day 0. Ovarian ultrasonography was performed every second day from Day 0 to 44 to record the size of 2 largest follicles and the corpus luteum (CL). Thereafter, examinations were done every 4 days until the third ovulation or Day 100, whichever came first. The first and second interovulatory intervals (IOI) were categorized as short (<12 days), normal (16-24 days), or long (>24 days), and the onset of the puberty was defined by the occurrence of 2 consecutive short or normal IOI (i.e. 3 uninterrupted ovulations). Proportional data were compared among groups by chi-squared test. Single-point measurements were compared by analysis of variance and multiple comparisons were made using Tukey’s test. Two heifers (one in each group) failed to ovulate during the experiment. The diameter of the largest follicle on Day 0 did not differ (P = 0.31) between the GnRH and Control groups (12.6 ± 0.37 mm and 13.1 ± 0.29 mm, respectively). The proportion of heifers that ovulated by Day 4 after treatment was higher in the GnRH than in the Control group (9/24 v. 1/22; P < 0.01). However, the proportion of heifers in the GnRH v. Control groups that ovulated twice (19/24 v. 18/22; P = 0.60) or 3 times (9/24 v. 9/22; P = 0.81) did not differ. The age at first ovulation tended to be younger in the GnRH group than in the Control (12 ± 0.97 v. 13 ± 0.90 months; P = 0.07), but the effect was attributed only to those heifers that ovulated in response to GnRH treatment (n = 9). The age at first ovulation was 11.2 ± 0.50, 12.7 ± 0.73, and 12.6 ± 0.90 months in GnRH-responders, non-responders, and the control group, respectively (P < 0.0001). One heifer that ovulated in response to GnRH treatment failed to ovulate again during the study period (Day 100). In 87.5% (7/8) of the heifers that responded to GnRH treatment and ovulated at least twice, the first IOI was long (55.5 ± 8.3 days). When data were combined between the GnRH non-responders and the control group (n = 35), the first IOI was short (8.9 ± 0.4 days) in 77% of the heifers, and the second IOI was of normal length (18.8 ± 0.9 days) in 93% of heifers. The age at the second ovulation in GnRH responders (12.7 ± 0.3 months) was similar (P = 0.82) to the age at first ovulation in GnRH non-responders (12.9 ± 0.1 months) and the control group (12.7 ± 0.2 months), indicating that GnRH treatment did not hasten the onset of continuous cyclicity. In conclusion, although GnRH treatment induced first ovulation in some peripubertal heifers, treatment did not hasten the onset of puberty. Research was supported by the Natural Sciences and Engineering Research Council of Canada.

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15 THE ADMINISTRATION OF GONADOTROPIN-RELEASING HORMONE AROUND THE FIRST POSTPARTUM MONTH INCREASES SUBSEQUENT REPRODUCTIVE PERFORMANCE IN DAIRY COWS

Reproduction Fertility and Development ◽

10.1071/rdv25n1ab15 ◽

2013 ◽

Vol 25 (1) ◽

pp. 154

Author(s):

J. K. Jeong ◽

H. G. Kang ◽

T. Y. Hur ◽

I. H. Kim

Keyword(s):

Dairy Cows ◽

Reproductive Performance ◽

Development Project ◽

Management Program ◽

Gonadotropin Releasing Hormone ◽

Control Group ◽

Breeding Period ◽

Cooperative Research ◽

Releasing Hormone ◽

And Control

Early postpartum cyclicity is related to subsequent fertility. This field study evaluated the effect of gonadotropin-releasing hormone (GnRH) administration around the first postpartum month on subsequent reproductive performance in dairy cows. Holstein dairy cows underwent ultrasonography at 30.0 (±6) days postpartum to determine the existence of ovarian structures including corpus lutea (CL), follicles, or cysts. The cows without CL were divided randomly into 2 treatment groups: GnRH group and control group. Cows in the GnRH group received an injection of 100 µg of GnRH (gonadorelin, Godorel, Uni-Biotech Co. Ltd., Korea; n = 151). Cows in the control group received no GnRH (n = 171). Cows diagnosed with endometritis at the time of ultrasonography were excluded from this study. Cows received the normal herd reproductive management program including estrous detection or synchronization, or synchronization of ovulation in the breeding period. The voluntary waiting period from calving to first AI in this study was 40 days. Pregnancy was determined per rectum 60 days after AI by both ultrasonography and palpation. Reproductive performance data were collected for a minimum of 210 days postpartum. Reproduction data between the GnRH and control groups were evaluated by chi-square test or the Cox proportional hazard model with the PHREG procedure using the SAS program (version 9.1, SAS Institute Inc., Cary, NC, USA). The number of days to first insemination after calving did not differ (P > 0.05) between the control group (80.9 ± 2.2 days) and the GnRH group (82.1 ± 2.3 days), while the pregnancy rate to first insemination tended to be higher (P = 0.1) in the GnRH group (42.3%) than in the control group (33.3%). Furthermore, the pregnancy hazard was higher by 210 days in milk for the GnRH group compared with the control group (hazard ratio = 1.33; P < 0.05), which resulted in a 26-day reduction in the median interval to pregnancy. In conclusion, the administration of GnRH around the first postpartum month improved subsequent reproductive performance in dairy cows. This work was carried out with the support of the Cooperative Research Program for Agriculture Science & Technology Development (project no. PJ008464) Rural Development Administration, Republic of Korea.

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The Effect of Gonadotropin Releasing Hormone Administration on Fertility and Embryonic Loss in Goats during the Anoestrus Period

Acta Scientiae Veterinariae ◽

10.22456/1679-9216.111167 ◽

2021 ◽

Vol 49 ◽

Author(s):

Ayşe Merve Köse ◽

Ece Koldaş Ürer ◽

Mustafa Kemal Sarıbay ◽

Gökhan Doğruer ◽

Fikret Karaka ◽

...

Keyword(s):

Pregnancy Rate ◽

Reproductive Performance ◽

Gonadotropin Releasing Hormone ◽

Control Group ◽

Progesterone Concentration ◽

Serum Progesterone ◽

Releasing Hormone ◽

Embryonic Life ◽

Embryonic Loss ◽

Oestrus Induction

Background: Following the induction of oestrus out of season in small ruminants, low fertility and variations in fertility rates are associated with embryonic losses. One of the main causes of embryonic loss is luteal dysfunction. Gonadotropin Releasing Hormone (GnRH) supports the luteal structure, and increasing progesterone levels may be beneficial in terms of promoting embryonic life. The main objective of the present study was to evaluate the efficacy of GnRH administration following an oestrus induction protocol in the anoestrus season for preventing embryonic loss in goats having failure to conceive during the season. Materials, Methods & Results: In the study, 106 Damascus goats aged 3-5 years and weighing 45-60 kg were used. The oestrus of 106 goats in the anoestrous group was stimulated with progesterone and pregnant mare serum gonadotropin (PMSG) treatment. Out of breeding season, goats were divided into the 4 following groups: GnRH0 (n = 27), GnRH7 (n = 26), GnRH0+7 (n = 27) and control (n = 26). In each goat, an intravaginal sponge (IS) containing 20 mg of fluorogestone acetate (FGA) was placed into the vagina and left for 9 days. With the withdrawal of the sponge, 550IU PMSG and 125 μg of d-cloprostenol were injected intramuscularly. Oestrus detection was made via teaser bucks for 3 days starting 24 h after withdrawal of the IS. Eighteen bucks known to be fertile were used for breeding. Goats in the oestrus period were mated via natural breeding. The GnRH analogue lecirelin was injected intramuscularly at breeding in the GnRH0 group, on day 7 post-breeding in the GnRH7 group, and both at breeding and on day 7 post-breeding in the GnRH0+7 group. No injections were given to the control group. Blood samples for progesterone measurement were taken by jugular vena puncturing on days 3, 6, 7, 10, 13, 16, and 19 after breeding from 10 randomly chosen goats in all groups. The goats with a level of > 3.5 ng/mL of progesterone on day 21 post-breeding were evaluated as pregnant. Pregnancy was also viewed on day 50 after breeding by real-time ultrasonography (USG) with a 5-7.5 MHz convex probe. The oestrus rate was 96.23% (102/106) in the goats. The rates of onset of oestrus between 36-48 h, 48-60 h and 60 h and beyond were 38.7% (41/106), 21.7% (23/106) and 35.8% (38/106), respectively. The total pregnancy rate was 35.8% (38/106). There were no statistically significant differences (P > 0.05) found for the pregnancy rate, embryonic death rate or progesterone concentration of the groups. However, serum progesterone levels were statistically different in the GnRH7 group compared with the control group (P < 0.05).Discussion: After synchronisation, various anti-luteolytic strategies can be used to support corpus luteum development and elevate progesterone concentration in the luteal phase to decrease embryonic loss and increase reproductive performance. Therefore, application of GnRH to support the luteal structure and to increase progesterone levels may be beneficial in terms of supporting embryonic life. The results showed that GnRH treatment on the day 7 post-breeding following oestrus induction, including FGA and PMSG, can increase serum progesterone levels in Damascus goats in the anoestrus period. However, following oestrus induction in the anoestrus period, it was seen that GnRH treatment at breeding or on day 7 after breeding did not have any positive effect on embryonic loss or reproductive performance. In conclusion, it was considered that this protocol could be implemented successfully, yielding a 35% pregnancy rate in Damascus goats in the anoestrus period, but embryonic loss must be deeply studied in detail.

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Pregnancy rates in hair sheep after Ovsynch synchronization and a combined intracervical fixed-time artificial insemination and 10-day mating period

Veterinary World ◽

10.14202/vetworld.2019.1779-1783 ◽

2019 ◽

Vol 12 (11) ◽

pp. 1779-1783

Author(s):

D. A. Vallejo ◽

J. D. Londoño ◽

Y. A. Yepes ◽

V. Tamayo ◽

A. F. Mejia ◽

...

Keyword(s):

Pregnancy Rate ◽

Artificial Insemination ◽

Prostaglandin F2α ◽

Fixed Time ◽

Pregnancy Rates ◽

Control Group ◽

Mating Period ◽

Mating Group ◽

Alternative Materials ◽

And Control

Aim: This study aimed to evaluate the pregnancy rates in hair ewes using an Ovsynch synchronization protocol under a breeding system that combines fixed-time insemination plus a 10-day mating period as an alternative. Materials and Methods: Through an experimental study (n=27), ewes were randomly located into one of three treatments: (1) Pre-synch (n=9): Prostaglandin F2α (PGF2α)+Gonadotropin-releasing hormone (GnRH)+PGF2α+GnRH; (2) Ovsynch (n=9): GnRH+PGF2α+GnRH; and (3) control: Ewes bred by natural mating (NM) (n=9). Ewes were fixed-time inseminated (fixed-time artificial insemination [FTAI]) with fresh semen, collected just before the insemination time through vaginoscopy at 16 h after the second GnRH (gonadorelin) injection. Each experimental group was placed separately during 15 days and, after this time, fertile rams were allowed back with ewes for a 10-day mating period. Control group ewes remained with the rest of the herd suitable for breeding and were bred under NM. Pregnancy diagnosis was performed by ultrasound at 28-, 56-, and 84-day post-breeding to differentiate between FTAI and NM pregnancies. Total (FTAI±NM) pregnancy rates at 56-day post-breeding were used to compared Pre-synch, Ovsynch, and control. For this purpose, two-tailed proportions comparison z-test was used with a 95% confidence level, for testing as the null hypothesis whether two proportions were equal. Results: Pregnancy rates were higher in control ewes (66.4%) than FTAI (46.6%). When pregnancy rates after a 10-day mating period (40%) were added, the final rate (86.6%) was significantly (p<0.05) higher in Ovsynch-based protocols. The pregnancy rate was significantly lower in FTAI ewes compared to FTAI +10-day mating group (p<0.05). The overall pregnancy rate was 88.0, 85.7, and 67.0 (p>0.05) for Pre-synch, Ovsynch, and control ewes, respectively. Conclusion: These results provide evidence on the benefits of combined FTAI protocols for improving the reproductive efficiency of sheep.

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157 PREGNANCIES AND CALVES AFTER TRANSFER OF IN VITRO-PRODUCED RIVER BUFFALO EMBRYOS AFTER CRYOPRESERVATION

Reproduction Fertility and Development ◽

10.1071/rdv24n1ab157 ◽

2012 ◽

Vol 24 (1) ◽

pp. 190 ◽

Cited By ~ 2

Author(s):

C. Galli ◽

R. Duchi ◽

G. Lazzari ◽

I. Lagutina ◽

S. Colleoni ◽

...

Keyword(s):

Pregnancy Rate ◽

Embryo Transfer ◽

Prostaglandin F2α ◽

Gonadotropin Releasing Hormone ◽

North Coast ◽

Transfer Program ◽

Embryo Production ◽

Releasing Hormone ◽

In Vitro Embryo Production

In the buffalo, the use of embryo-based biotechnologies for breeding and genetic improvement is still very limited because multiple-ovulation embryo transfer delivers poor results compared with cattle and in vitro embryo production has been used mainly for research purposes. At present, very few reports are available on the transfer of in vitro-produced (IVP) and cryopreserved buffalo embryos. Therefore, the scope of this work was to perform a pilot study to evaluate the viability of frozen-thawed IVP embryos by nonsurgical embryo transfer to recipients in an IVF-embryo transfer program on a farm located on the north coast of Colombia, South America. Buffalo oocytes were recovered at the slaughterhouse from selected donors, matured in vitro for 18 to 20 h in TCM-199 + 10% FCS and 0.5 IU of FSH and 0.5 IU of LH in 5% CO2 at 38.5°C. Four different bulls were used for IVF. After thawing, the semen was separated on a Percoll® gradient and then diluted into SOF-IVF media supplemented with 1 μg mL–1 of heparin and phenylalanine. Presumptive zygotes were cultured in modified SOF supplemented with MEM amino acids for 6 days. Half of the medium was replaced on Day 4 and 6. Developing embryos were selected for freezing on Day 6 and 7. Grade 1 embryos were frozen at the blastocyst stage by slow cooling in 10% glycerol or 1.5 M ethylene glycol. Recipients (heifers n = 79 and uniparous cows n = 17) were synchronized using the CIDR-Synch protocol: on Day 0, gonadotropin-releasing hormone was injected and a CIDR was inserted; on Day 7, prostaglandin F2α was administered; on Day 9, the CIDR was removed; on Day 11, a second injection of gonadotropin-releasing hormone was given; and on Day 17, the embryo was transferred. Each female received, nonsurgically, 1 or 2 embryos in the ipsilateral horn to the functional corpus luteum evaluated by ultrasonography. Pregnancies were evaluated by ultrasonography 30 days after transfer and confirmed by rectal palpation 30 days later. This work was performed in 2 successive experiments during the breeding seasons (January and December, respectively). Overall, 96 recipients were transferred, with 136 embryos obtaining 23 pregnancies (24.2%). There were no statistical differences in pregnancy rate between heifers and cows (25.3 vs 17.7%) and between single (n = 56) and double (n = 39) embryo transfers (21.4 vs 27.5%) by chi square test (P > 0.05). To date, 4 females and 5 males have been born by spontaneous calving (1 stillborn male due to dystocia), 3 pregnancies have been aborted (13%) and 11 pregnancies are ongoing (>7 months). The pregnancy rate obtained in this study in farm conditions (24.2%) is lower than generally obtained with frozen IVP cattle embryos, but it is still a good result in buffalo, where even conventional AI provides a lower success rate as compared with cattle. Finally, this work demonstrates that in vitro embryo production can be successfully implemented in buffalo breeding programs for the exploitation of superior genetics. This work was supported by Regione Lombardia, Por Fers 2007–2013, n°13827741, InnovaB.

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The Early Start of Gonadotropin-releasing Hormone Antagonist Versus Flexible Antagonist Ovarian Stimulation Protocol in Poor Responders: A Randomized Clinical Trial

10.21203/rs.3.rs-53355/v1 ◽

2020 ◽

Author(s):

Tayebeh Esfidani ◽

Ashraf Moini ◽

Arezoo Arabipoor ◽

Maryam Farid Mojtahedi ◽

Shima Mohiti ◽

...

Keyword(s):

Ovarian Stimulation ◽

Early Onset ◽

Randomized Clinical Trials ◽

Gonadotropin Releasing Hormone ◽

Control Group ◽

Early Start ◽

Releasing Hormone ◽

Significant Difference ◽

And Control ◽

Antagonist Group

Abstract Background: Determining the initiation day of antagonist administration is an important and challenging issue and different results have been reported in the previous studies. The present study was designed to compare the controlled ovarian hyperstimulation (COH) cycles outcomes of the early start of gonadotropin-releasing hormone antagonist (GnRH-ant) protocol with conventional flexible GnRH-ant protocol in patients with poor ovarian response (POR) diagnosis. Methods: This randomized controlled trial was performed on infertile women who were diagnosed as poor ovarian responder in IVF/ICSI cycles at Arash Women’s Hospital affiliated to Tehran University of Medical Sciences between September 2019 and May 2020. POR was defined according to the Bologna criteria and the eligible women were randomly allocated into an experimental (early onset GnRH-ant) and control (flexible GnRH-ant) groups. The women in the experimental group received recombinant gonadotropins (150-225 IU) and GnRH-ant (0.25 mg) simultaneously on the second day of the cycle. In control group, the starting and dose of gonadotropins were similar but daily administration of GnRH-ant was initiated when the leading follicle diameter was ≥ 13 mm. The IVF/ICSI outcomes were compared between groups.Results: Totally, 116 women were randomly assigned to early start antagonist group (n=58) and control group (n=58). The analysis showed that the two groups did not have a statistically significant difference in terms of the ovarian stimulation duration and the total dose of used gonadotropins. Although, the total number of MII oocytes in early start of antagonist group was significantly higher than that of in control group (P=0.04). In the following, clinical and ongoing pregnancy rates per ET in early start of antagonist group were significantly higher than those of in control group (P=0.02 and P=0.03, respectively); however, the implantation and miscarriage rates were similar between group.Conclusion: The early onset of GnRH-ant protocol can improve the number of retrieved and MII oocytes rates and probably the pregnancy outcome after fresh embryo transfer in POR patients; however, larger randomized clinical trials are required to compare the pregnancy outcomes after this approach with other COH protocols with considering cost-effectiveness issue.Trial registration: IRCT, IRCT20110731007165N9. Registered 8 February 2020 – Registered while recruiting, https://www.irct.ir/trial/45024.

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

Reproduction Fertility and Development ◽

10.1071/rdv26n1ab7 ◽

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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121 Ovulatory response to gonadotropin-releasing hormone relative to day and diameter of dominant follicle during the first follicular wave in Beetal goats

Reproduction Fertility and Development ◽

10.1071/rdv31n1ab121 ◽

2019 ◽

Vol 31 (1) ◽

pp. 186

Author(s):

W. Ahmad ◽

M. I.-R. Khan ◽

A. Murtaza ◽

I. Mohsin ◽

A. Riaz ◽

...

Keyword(s):

Growth Rate ◽

Prostaglandin F2α ◽

Binary Logistic Regression ◽

Gonadotropin Releasing Hormone ◽

Oestrous Cycle ◽

New Wave ◽

Dominant Follicle ◽

Releasing Hormone ◽

Follicular Wave ◽

Ovulatory Follicles

In Beetal goats under subtropical conditions, ovulatory response of first-wave dominant follicle based on diameter and day of oestrous cycle is unknown to date. The objective of this study was to evaluate the ovulatory response to gonadotropin-releasing hormone (GnRH) relative to day and diameter of dominant follicle during the first follicular wave in Beetal goats. Fifty goats were synchronized using a single dose of prostaglandin F2α (75 µg; D+ cloprostenol, Fatro, Italy), and scanned every 6 hours for ovulation using a 7.5-MHz trans-rectal transducer (Honda HS: 1500, Japan). Following ovulation (Day 0), goats (n=40; 10/day) were given GnRH (25µg lecirelin, Fatro, Italy) on Days 2, 4, 6, and 8 of oestrous cycle. Follicular dynamics was monitored daily from D 0 until GnRH, and every 4 hours after GnRH until ovulation. Ovulation frequency relative to day and dominant follicular diameter was analysed by binary logistic regression, whereas diameter of dominant follicle at time of GnRH, ovulation time, time of wave emergence and growth rate of dominant follicle following GnRH were analysed by one-way ANOVA and independent sample t-test (SPSS 20, IBM Corp., Armonk, NY, USA). Eighty percent of the goats ovulated within 74.7±1.3h after prostaglandin F2α. Overall, 37% (14/38) of the goats ovulated following GnRH within 12.0±1.5h. Ovulations (%) following GnRH were higher (P=0.03) on Day 4 than 2 (60 v. 10%; i.e. 14 times higher than Day 2) and decreased gradually from Day 4 to 8 (P>0.05). Similarly, ovulations following GnRH were higher (P=0.00) in first-wave dominant follicles having diameter 6.1-7.0mm than those having less than 6.1mm (88v. 23%; i.e. 24 times higher than <6.1mm). Ovulations (%) decreased as the diameter of dominant follicle increased from 6.1-7.0mm (P>0.05). Diameters of ovulatory follicles at time of GnRH between Day 2, 4, 6, and 8 were not different (P>0.05). Regardless of day of GnRH treatment, diameter of ovulatory v. anovulatory follicles differed (6.44±0.03v. 5.1±0.4 mm; P=0.00). Overall, growth rate of dominant follicles following GnRH was 0.2±0.11mm and did not differ between ovulatory and anovulatory goats (0.29±0.13v. 0.13±0.15 mm; P>0.05). Interval to the emergence of a new wave following GnRH was prolonged for Day 4 compared to Day 2, 6, and 8 (i.e. 22v. 8, 11, and 12 h; respectively, P<0.05). In conclusion, GnRH treatment at Day 4 resulted in maximum ovulations as the first-wave dominant follicle reached a size of 6.1 to 7.0 mm.

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