13 USE OF EQUINE CHORIONIC GONADOTROPIN OR FOLLICLE-STIMULATING HORMONE-LUTEINIZING HORMONE AT IMPLANT REMOVAL OR AT FIXED-TIME ARTIFICIAL INSEMINATION TIME IN PREGNANCY RATE OF SUCKLED NELLORE COWS

2015 ◽  
Vol 27 (1) ◽  
pp. 99

Use of eCG as an inducer of follicular growth has improved the efficacy of fixed-time artificial insemination (FTAI) protocols and increased the ovulatory responses and pregnancy rates in beef cattle with low body condition scores (BCS) or are recently postpartum and anestrous. However, there are other gonadotropins such as FSH in different commercial applications (Pluset® – FSH : LH proportion ~50.0%) that could be potentially used to increase follicular growth but with controversial results. The goal of this trial was to evaluate the effects of replacing eCG with FSH/LH in two moments on the pregnancy rates (PR) of lactating Bos indicus cows raised in native grassland at Pantanal. The cows were subjected to a synchronization-of-ovulation protocol and FTAI based on progesterone, oestradiol benzoate (EB), and prostaglandin F2α. On Day 0, Nellore multiparous cows (n = 352) at 42 days postpartum with BCS = 4.9 (1–9) were evaluated by transrectal ultrasonography and received progesterone implant (DIB 1.0 g of progesterone) plus 2 mg of EB IM. Devices were removed and prostaglandin F2α was injected on Day 8 with 1 mg of EB. At the time of implant removal, the animals received T1 – 1 mL of saline solution IM (control; n = 80); T2 – 300 IU IM of eCG (Novormon®; ECG; n = 92); T3 – 40 IU IM of FSH/LH (Pluset®; Pluset; n = 98). The T4-group cows received 40 IU IM of FSH/LH (Pluset®) at FTAI time (Pluset-FTAI; n = 82); cows were timed-AI on Day 10 (44–48 h after implant removal) and evaluated by transrectal ultrasonography to measure the preovulatory follicle (POF) at FTAI and to estimate the pregnancy rate on Day 45. The effects of the treatment, sire, and BCS on pregnancy rate were evaluated using PROC GLIMMIX (SAS Institute Inc., Cary, NC). Because there was no difference between BCS, sire, and PR, they were removed from model. Pregnancy rate was not different between the treatment groups (control: 38.70%; ECG: 51.08%; Pluset: 45.91%, and Pluset-FTAI: 39.02%; P > 0.05), but the difference was found in POF, higher in ECG group – 13.53 mm compared with others (Pluset: 12.79 mm; control: 11.73 mm, and Pluset-FTAI: 12.01 mm; P < 0.05). Although PR was not different between treatments, the data are in agreement with the size of POF, where the largest POF are associated with tendency of higher pregnancy rates in ECG group. In conclusion, commercial FSH solution does not provide increases in PR, and eCG increases the preovulatory follicles in Nellore cows with a low-moderate BCS submitted to a progesterone-based FTAI protocol with EB at implant removal.

2014 ◽  
Vol 43 (7) ◽  
pp. 358-362 ◽  
Author(s):  
Ériklis Nogueira ◽  
Dayanna Schiavi do Nascimento Batista ◽  
Luiz Carlos Cesar da Costa Filho ◽  
Alexandre Menezes Dias ◽  
Juliana Corrêa Borges Silva ◽  
...  

2008 ◽  
Vol 20 (1) ◽  
pp. 89
Author(s):  
M. F. Pegorer ◽  
R. L. Ereno ◽  
C. M. Barros

Previous reports indicate that a high concentration of serum progesterone (P4) decreases LH pulse frequency (Burke et al. 1996 Anim. Reprod. Sci. 45, 13–28) and, consequently, follicular growth. This may reduce the efficiency of fixed-time artificial insemination (FTAI) protocols that utilize P4 in Bos indicus heifers (Marques et al. 2005 Acta Sci. Vet.). The objective of the present work was to evaluate the influence of different P4 concentrations on the ovulation and pregnancy rates of zebu heifers subjected to hormonal protocols for FTAI. Four hormonal protocols with different P4 concentrations were used to induce synchronization of ovulation in Nelore (Bos indicus) heifers (n = 292). Before the beginning of the treatments, the animals were subjected to ovary evaluations by ultrasonography (Aloka SSD 500, 5-MHz probe; Aloka, Tokyo, Japan) twice in an interval of 10 days. Only heifers with a corpus luteum (CL) in at least one of the ultrasonographic evaluations were utilized. At a random stage of the estrous cycle, the selected heifers received an intravaginal progesterone-releasing device containing 0.558 g of P4 [Triu�, Biogenesis, Buenos Aires, Argentina; Treatment 1 (T1); n = 76], or 1 g of P4 [Cronipress�, Biogenesis; Treatment 2 (T2); n = 70], or 0.558 g of P4 and prostaglandin F2α (PGF2α) [150 �g d-cloprostenol, IM, Croniben�, Biogenesis; Treatment 3 (T3), n = 75], or 1 g of P4 and PGF2α [Treatment 4 (T4), n = 71]. At the time of intravaginal device insertion (Day 0 = D0), all animals received 2 mg of estradiol benzoate (EB, Bioestrogen�, IM, Biogenesis), and PGF2α was administered only in animals from groups T3 and T4. Eight days later (D8), PGF2α (0.150 g d-cloprostenol) was administered to all heifers and the P4 source was removed. Twenty-four h after removal of the intravaginal device, the heifers were treated with EB (1 mg, IM), and 30 to 36 h later all animals were fixed-time inseminated (FTAI, D10), without estrus detection. In a subset of heifers from each group (T1 = 28; T2 = 34; T3 = 33; T4 = 31), ovarian ultrasonography was performed on D9 (at 8:00 A.M.) and D11 (at 14:00 P.M.) in order to determine ovulation rate after each treatment. The data were analyzed by logistic regression (GENPROC, SAS; SAS Institute, Inc., Cary, NC, USA). Ovulation rates after treatments T1, T2, T3, and T4, were, respectively, 71.4% (20/28), 76.5% (26/34), 84.9% (28/33), and 70.9% (22/31), and there was no significant difference among groups (P > 0.05). Pregnancy rates, ascertained by ultrasonography 40 days after AI, were 30.2% (23/76), 25.7% (18/70), 33.3% (25/75), and 28.2% (20/71), respectively, for T1, T2, T3, and T4, and likewise there was no significant difference among groups (P > 0.05). It is concluded that reduction of progesterone concentration in the intravaginal device (1 g v. 0.558 g) associated or not with administration of PGF2α at the beginning of treatments did not significantly influence ovulation and pregnancy rates in Nelore heifers submitted to a FTAI protocol. Additional experiments are underway to confirm or not the present results. This work was supported by FAPESP (Brazil) and BIOGENESIS (Argentina).


2019 ◽  
Vol 12 (11) ◽  
pp. 1779-1783
Author(s):  
D. A. Vallejo ◽  
J. D. Londoño ◽  
Y. A. Yepes ◽  
V. Tamayo ◽  
A. F. Mejia ◽  
...  

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.


2020 ◽  
Vol 98 (7) ◽  
Author(s):  
Ramiro V Oliveira Filho ◽  
Reinaldo F Cooke ◽  
Gustavo A de Mello ◽  
Victor M Pereira ◽  
Jose Luiz M Vasconcelos ◽  
...  

Abstract Clitoral stimulation after artificial insemination (AI) in beef cattle is a common practice utilized by AI technicians; however, the effect of clitoral stimulation during fixed-time AI (TAI) is still unknown. The objective of the present experiment was to evaluate the effect of clitoral stimulation on temperament responses and pregnancy rates to TAI in Bos indicus beef cows. A total of 1,186 multiparous Nellore cows across three different locations were assigned to an estradiol/progesterone-based estrus synchronization + TAI protocol (day −11 to 0). Cows were randomly assigned to receive either 3 s of clitoral stimulation (n = 602) or no clitoral stimulation (n = 584) immediately after TAI (day 0). Cow body condition score (BCS) was recorded on day −11. Estrus expression was evaluated based on estrus detection visual aid patch activation on day 0 (estrus, ≥50% activated; no estrus, &lt;50% activated). Temperament was assessed by individual chute score based on a 5-point scale before TAI, and individual exit velocity was measured after clitoral stimulation. Pregnancy diagnosis was performed 30 d after TAI via transrectal ultrasonography. Pregnancy rate to TAI was positively affected by BCS (P &lt; 0.01) and estrus expression (P = 0.03). Pregnancy rates of cows receiving clitoral stimulation did not differ (P = 0.39) from cows non-stimulated (47.5 ± 4.6% vs. 44.3 ± 4.6%, respectively). No interaction of clitoral stimulation and estrus expression was observed (P = 0.26). Chute score was positively correlated to exit velocity (P &lt; 0.01; r = 0.29); however, clitoral stimulation did not affect exit velocity (P = 0.86). In summary, pregnancy rates to TAI are influenced by various factors and multiple strategies have the potential to increase the fertility of beef cows submitted to TAI; however, clitoral stimulation of Bos indicus beef cows did not improve TAI pregnancy rate.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 125-126
Author(s):  
Vitor R G Rodrigues Gomes Mercadante ◽  
G Cliff C Lamb ◽  
Nicky Oosthuizen ◽  
Nicholas W Wege Dias ◽  
Stefania Pancini ◽  
...  

Abstract Pre-synchronization strategies with prolonged exposure to exogenous progesterone have the potential to alter estrus expression and improve fertility in replacement beef heifers. The objective of this study was to evaluate the estrus response and pregnancy rate of beef heifers enrolled in two fixed-time artificial insemination (TAI) protocols. A total of 306 heifers (14 ± 2 months of age; 372 ± 24 kg body weight [BW]) at three locations were enrolled in the study. Within location, heifers were stratified by age and BW and randomly assigned to one of two treatments: 1) PG-CIDR54 (n = 152), heifers were administered prostaglandin F2α (PGF; 25 mg) and a controlled internal drug releasing (CIDR) insert (Day -14), an injection of GnRH [100 μg (Day -7)], PGF injection and CIDR removal (Day 0), and a second injection of GnRH concurrently with TAI 54 ± 2 h later (Day 2); 2) 7-day CO-Synch+CIDR (CTRL; n = 154), heifers were administered GnRH (100 μg) and a CIDR insert (Day -7), PGF (25 mg) injection and CIDR removal (Day 0), and a second injection of GnRH concurrently with TAI 54 ± 2 h later (Day 2). All heifers received an estrus alert patch on Day 0 and were evaluated for patch activation at TAI on Day 2. Pregnancy was diagnosed by transrectal ultrasonography between 35 and 55 days after TAI. The percentage of heifers exhibiting estrus between Day 0 and 2 was greater (P &lt; 0.01) in PG-CIDR54 compared with CTRL (77.0 and 39.6%, respectively). In addition, pregnancy rate to TAI tended (P = 0.08) to be greater for PG-CIDR54 compared with CTRL (48.0 and 38.3%, respectively). We conclude that beef heifers enrolled in the PG-CIDR54 protocol had increased estrus expression and tended to have greater pregnancy rate when compared with heifers enrolled in the 7-day CO-Synch+CIDR protocol.


Author(s):  
Abubakr O. Ismail ◽  
◽  
Erneo B. Ochi ◽  
Ambrose S. Jubara ◽  
Bakri Ahmed A/Rahim ◽  
...  

A comparative hormonal study of prostaglandin, gonadotropin releasing hormone and their combination was conducted on 30 randomly selected cross-bred dairy cows of SEMEX project for artificial insemination in Hillat Kuku, Khartoum North, Sudan. The study attempts to determine the response of the animals to hormonal induction and synchronization of estrous as well as fertility following fixed time artificial insemination. Three treatment groups of 10 cows each were undertaken. Groups 1, 2 and 3 involved administration of prostaglandin F2α (PGF2α), gonadotropin releasing hormone (GnRH) and a combination of PGF2α + GnRH, respectively. Descriptive statistical analysis was performed. The results revealed that all the three protocols induced and synchronized estrous were almost synchronous in all the treated groups. However, protocol 3 revealed a significantly (p<0.05) better result of 70% pregnancy rate compared to other two protocols that equally provided 50% pregnancy rates. The study resolves that protocol 3 be highly recommended to change the mindset of farmers about the spread of reproductive technology in Sudan. Protocols 1 and 2 provided acceptable pregnancy rates that can be enhanced with the improvement of management.


2022 ◽  
Author(s):  
Murat Can Demir ◽  
Cihan Kaçar ◽  
Umut Çağın Arı ◽  
Semra Kaya ◽  
Oğuz Merhan ◽  
...  

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.


2020 ◽  
Vol 89 (4) ◽  
pp. 307-315
Author(s):  
Hasan Alkan ◽  
Huseyin Erdem

The aim of this study was to investigate the effects of hormonal support on the pregnancy rate in repeat breeder cows. Prostaglandin F2α + Ovsynch oestrus synchronization protocol was applied to the cows. Following the fixed time insemination (day 0), the cows were divided into 4 groups. In Group 1 (n = 42), progesterone releasing intravaginal device (PRID) was placed vaginally at 84 h and removed on the 9th day after the artificial insemination. In Group 2 (n = 40), the cows were administered human chorionic gonadotropin (hCG) on the 7th day. Group 3 (n = 45) was applied a combination of progesterone and hCG. Group 4 (n = 42) was not given any treatment. Blood samples were collected from all cows 4 times on days 3.5, 7, 12, and 18 to evaluate progesterone concentrations. The pregnancy rates were 40.47%, 37.50%, 44.44%, and 30.95% in Group 1, 2, 3, and 4, respectively (P > 0.05). In addition, in cows with progesterone concentrations <2 ng/ml on day 3.5, the pregnancy rates were found to be lower than in the cows with progesterone concentrations >2 ng/ml in Group 4 (P < 0.05). Progesterone supplementation in cows with progesterone concentrations < 2 ng/ml appeared to increase pregnancy rates (P < 0.05) in Groups 1 and 3. As a result, post-insemination hormonal applications in the repeat breeder cows did not increase the pregnancy rate. However, it was concluded that determination of progesterone concentrations on day 3.5 following artificial insemination and then hormonal support in the cows with low concentrations would increased the pregnancy rate.


1990 ◽  
Vol 51 (3) ◽  
pp. 613-621 ◽  
Author(s):  
P. F. Fennessy ◽  
C. G. Mackintosh ◽  
G. H. Shackell

ABSTRACTSix experiments involving the artificial insemination (AI) of a total of 300 female red deer (hinds) with frozen-thawed red deer semen (collected by electro-ejaculation) were conducted over 3 years. Insemination took place at fixed times following various oestrous synchronization procedures using progesterone withdrawal and treatment with pregnant mare's serum gonadotropin (PMSG). In the 1st year, the experiments evaluated basic AI techniques in which pregnancy rates were 45% in 20 hinds receiving two inseminations per vaginam (PV) and 56% in 27 hinds inseminated by the laparoscopic intrauterine method (IU). In the 2nd year, the experiments involved comparisons of the progesterone regime, one or two PV inseminations, and the timing of a single PV insemination. There was no effect of replacement of the progesterone device after 9 days and withdrawal 3 days later compared with the use of one device for the whole period in two experiments. The pregnancy rate for a double PV insemination was significantly higher than for a single PV insemination (58 and 34%; P < 0·05) and there was also a small effect of timing of insemination relative to the synchronization treatment. In the 3rd year all hinds were inseminated by the IU method. The experiments involved a comparison of various times of AI following progesterone withdrawal and a comparison of the progesterone regime. The overall pregnancy rate for 63 hinds inseminated was 56% with no difference between three times of insemination (48, 52 and 55 h). In the second experiment, the difference in pregnancy rate between treatment with progesterone for 15 days and 12 days (44 and 72% for 18 hinds per group) was not significant, but the interaction between the length of progesterone treatment and insemination time was significant (P < 0·05), with the 12-day progesterone/55 h insemination giving a much higher pregnancy rate than the 15-day/55 h insemination (89 and 20% respectively). Although no experiments involved direct comparisons of the routes of insemination, overall pregnancy rates were 56% for IU, 53% for double PV and 35% for single PV inseminations.


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