scholarly journals 20 EFFECTS OF DOSE OF ESTRADIOL BENZOATE AND PROGESTERONE IN PROSTAGLANDIN-TREATED BEEF HEIFERS

2005 ◽  
Vol 17 (2) ◽  
pp. 160
Author(s):  
M. Martínez ◽  
M. Caccia ◽  
M. Colazo ◽  
G. Bó ◽  
J. Kastelic ◽  
...  
Keyword(s):  
Animal Health ◽  
Follicular Development ◽  
Estradiol Benzoate ◽  
Beef Heifers ◽  
Once Daily ◽  
Treatment Groups ◽  
Dose Time ◽  
Follicular Wave ◽  
Time Interaction ◽  
To Receive

Estradiol and progesterone have been used to synchronize follicular wave emergence and ovulation in a two-dose prostaglandin (PGF)-based synchronization program (Martínez et al. 2004 Theriogenology 62, 363–372). However, it was observed that some heifers displayed estrus prior to the second PGF, suggesting that premature luteolysis may have occurred. An experiment was designed to determine the effects of dose of estradiol benzoate (EB) and/or progesterone (P) on follicular and luteal dynamics in a two dose PGF-based protocol in beef heifers. In two replicates, beef heifers (n = 28; Simmental, Hereford, and Charolais crosses, 350 to 450 kg) received 500 μg cloprostenol (Schering-Plough Animal Health, Pointe-Claire, PQ, Canada) on Day −7. On Day 0, heifers were randomly allocated to nine treatment groups to receive 0, 1, or 2 mg of EB and 0, 50, or 100 mg of P i.m. in canola oil in a 3 × 3 factorial design. A second PGF treatment was administered on Day 14. Ultrasonography was done once daily from Days −5 to 9, and every 12 h thereafter until ovulation. Blood samples were collected at 12-hour intervals from Day 0 to 5 for estradiol and FSH concentrations, and every 24 h for progesterone. The effects of EB and P and their interaction on corpus luteum (CL), follicles, and hormone profiles were analyzed by analysis of variance, and means were compared by LSD or Tukey's test. All variables were normally distributed (Wilk-Shapiro test and rankit plots). The day of follicular wave at the time of treatment tended to vary among groups (P = 0.08) and the diameter of the dominant follicle also differed (P < 0.05). The interval from treatment to wave emergence was shorter (P < 0.05) in heifers that received 2 mg EB (4.6 ± 0.3 d) than in those that did not receive EB (5.9 ± 0.6 d), while the 1 mg EB group (5.1 ± 0.6 d) was intermediate. The interval to wave emergence in the 2 mg EB group was the least variable (P < 0.05). There was no effect of EB (P = 0.72) on the diameter of the CL at the time of the second PGF, but there was an effect of P treatment (P = 0.01). The variability of the interval from the second PGF to ovulation may have been influenced by treatment group but was statistically not significant (P < 0.1). There was an effect of time (P < 0.01) on plasma progesterone concentrations and a P × time interaction (P = 0.06) can also be assumed. Estradiol concentrations were affected by EB dose, time, and EB × time interaction (all P < 0.01). FSH concentrations were modified by time (P < 0.01). In summary, treatment with EB 7 days after a single injection of PGF affected follicular development, while P treatment at that time appeared to influence CL function.

39 EFFECT OF TIME OF FIXED-TIME AI ON PREGNANCY RATES IN ZEBU CROSS-BRED BEEF HEIFERS TREATED WITH PROGESTERONE RELEASING DEVICES AND ESTRADIOL CYPIONATE

2010 ◽  
Vol 22 (1) ◽  
pp. 177 ◽  
Author(s):  
M. Ramos ◽  
L. Cutaia ◽  
P. Chesta ◽  
G. A. Bó
Keyword(s):  
Bos Taurus ◽  
Body Condition Score ◽  
Bos Indicus ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Beef Heifers ◽  
Treatment Groups ◽  
Condition Score ◽  
To Receive

Two experiments were designed to evaluate the effect of the timing of fixed-time AI (FTAI) in relation to the removal of an intravaginal progesterone-releasing device (1 g of progesterone, DIB, Syntex SA, Buenos Aires, Argentina) on pregnancy rates in Bos indicus × Bos taurus cross-bred heifers. In experiment 1, 285 Bonsmara × zebu cross-bred heifers, between 18 and 24 months of age and with a body condition score (BCS) between 3.0 and 3.5 (1-5 scale) were used. On the day of initiation of treatment (Day 0), the heifers’ ovaries were palpated (92% of them had a CL) and they received a new DIB plus 2 mg of estradiol benzoate (EB; Syntex SA) and 250 μg of cloprostenol (Ciclase DL, Syntex SA). On Day 8, DIB devices were removed and all heifers received 250 μg of Ciclase plus 0.5 mg of estradiol cypionate (ECP; Cipiosyn, Syntex SA). At that time the heifers were randomly divided to receive FTAI between 48 to 49 h, 53 to 54 h, or 58 to 59 h after DIB removal. The heifers underwent FTAI with semen from 4 bulls by 2 inseminators. In experiment 2, 260 heifers from the same group as those used in experiment 1 (87% with a CL) were treated exactly as those in experiment 1, except that previously used DIB was inserted on Day 0. Pregnancy diagnosis was performed 30 days post-fixed-time AI by ultrasonography. The data were analyzed by logistic regression, taking into account the effect of time of FTAI, semen, and inseminator on pregnancy rates. In experiment 1, pregnancy rates were lower (P = 0.04) in the heifers undergoing FTAI between 48 and 49 h after DIB removal (46/95, 48.4%) than those undergoing FTAI 53 to 54 h (61/99, 61.6%) or 58 to 60 h (57/91, 62.6%) after DIB removal. However, no differences in pregnancy rates were found (P = 0.72) in experiment 2 between the 3 treatment groups, with 39/91 (42.9%) for the 48 to 49 h group, 45/89 (50.6%) for the 53 to 54 h group, and 35/89 (43.8%) for the 58 to 59 h group. There was no effect of the semen or inseminator (P > 0.2) in either experiment. We conclude that when Bos indicus × Bos taurus beef heifers are synchronized with new DIB devices and ECP, higher pregnancy rates are obtained in heifers undergoing FTAI late (between 53 to 60 h after DIB removal) than in those undergoing FTAI early (48 to 49 h after DIB removal). However, time of insemination does not apparently affect pregnancy rates when Bos indicus × Bos taurus beef heifers are synchronized with previously used DIB devices and ECP.

27 FOLLICULAR RESPONSE TO DIFFERENT eCG DOSES IN AN OVSYNCH + PROGESTERONE PROTOCOL IN BEEF HEIFERS

2010 ◽  
Vol 22 (1) ◽  
pp. 171
Author(s):  
M. F. Martínez ◽  
D. Tutt ◽  
L. Proctor ◽  
J. L. Juengel
Keyword(s):  
New Zealand ◽  
Animal Health ◽  
Follicular Development ◽  
Dominant Follicle ◽  
Treatment Groups ◽  
Follicular Wave ◽  
Multiple Ovulation ◽  
Array Transducer ◽  
Pfizer Animal Health ◽  
Follicular Response

An experiment was designed to evaluate the effect of different doses of eCG on ovarian follicular dynamics in heifers treated with a Ovsynch plus progesterone protocol. Twenty-five cyclic yearling Black Angus heifers (373.0 ± 35.7 kg), in 2 replicates, received an injection of 100 μg of GnRH (Ovurelin, Bomac Laboratories Ltd., Auckland, New Zealand) i.m. and an intravaginal progesterone device (1.38 g of progesterone; Eazi-Breed CIDR, Pfizer Animal Health, New Zealand) on Day 0 (beginning of the experiment), followed by 500 μg of cloprostenol (PGF, Estrumate, Intervet/Schering-Plough Animal Health, Auckland, New Zealand) i.m. on Day 7, and a second 100 μg of GnRH injection given i.m. on Day 9 (56 h after PGF). At the time of PGF treatment, heifers were randomly assigned to 5 treatment groups to receive 0, 300, 500, 700, or 1000 IU of eCG (Folligon, Intervet/Schering-Plough Animal Health) i.m. Heifers were monitored by ultrasonography (Aloka 900-SSD equipped with a 7.5-MHz linear-array transducer; Aloka, Tokyo, Japan) daily from Day 0 to 9 (GnRH), and then every 12 h until ovulation. Data were analyzed by one-way ANOVA or Kruskall-Wallis test, and means or ranks were compared with LSD or Wilcoxon rank sum tests, respectively. Because a replicate effect was observed (P < 0.05) in the size of the dominant follicle at the second GnRH and prior to ovulation, replicate effect was included in the analysis. The luteal area at PGF treatment was significantly greater (P < 0.01) in heifers that ovulated (750.0 ± 97 mm2) in response to the first GnRH treatment than in those that did not (301.6 ± 42.7 mm2). The diameter of the dominant follicle at the time of PGF treatment was also greater (P < 0.05) in ovulating (11.2 ± 0.4 mm) than in nonovulating (9.7 ± 0.5 mm) heifers. The interval from the first GnRH treatment to the emergence of the next follicular wave was longer (P = 0.50) and more variable in heifers that did not ovulate (2.9 ± 0.4 d; n = 27) than in those that ovulated (1.9 ± 0.2 d; n = 23). There was no effect (P < 0.37) of eCG on the interval from PGF to ovulation (86 ± 1.9 h). The number of ovulations after the second GnRH was higher (P = 0.01) in the group of heifers treated with 1000 IU of eCG (1.8 ± 0.4) than in the other groups (1.0 ± 0.0; 1.1 ± 0.1; 1.2 ± 0.1; 1.0 ± 0.1). There was an effect of day of follicular wave emergence on the number of ovulations (P < 0.01). Heifers with a wave emerging 1 to 3 days after the first GnRH (n = 37), had one ovulation (1.0 ± 0.0), whereas heifers with a wave emerging on Day 4 (3 out of 4 heifers) and Days 5 to 7 (n = 9), ovulated 2 or more follicles. In summary, the multiple ovulation effect occurred when eCG was given to heifers with a follicular wave emerging on or after Day 4, and was potentiated when heifers received 1000 IU of eCG. Although the dose of eCG given at the time of PGF treatment in an Ovsynch program has a significant effect on follicular development, the time of emergence of the dominant follicle appeared to be more important in the ovulation of preovulatory follicle/s after the eCG and the second GnRH treatment.

294 SUPERSTIMULATION IN THE FIRST FOLLICULAR WAVE, WITHOUT THE USE OF ESTRADIOL IN BONSMARA CATTLE

2008 ◽  
Vol 20 (1) ◽  
pp. 226 ◽  
Author(s):  
D. Carballo Guerrero ◽  
A. Tribulo ◽  
R. Tribulo ◽  
H. Tribulo ◽  
G. A. Bo
Keyword(s):  
Animal Health ◽  
Estradiol Benzoate ◽  
Control Group ◽  
Wave Group ◽  
Treatment Groups ◽  
Follicular Wave ◽  
Group Data ◽  
Mate Removal ◽  
On Farm ◽  
Experimental Group

Protocols that control follicular wave emergence and ovulation have had a great impact on the application of commercial on-farm embryo transfer because they permit the initiation of superstimulatory treatments at a self-appointed time. However, the most common approach for the synchronization of follicular wave emergence for superstimulation involves the use of estradiol or its esters that are not commercially available in many countries. Therefore, an experiment was designed to evaluate a protocol in which the superstimulation treatment began at the time of emergence of the first follicular wave without the use of estradiol. Bonsmara donors (29 cows and 41 heifers) were randomly allocated to one of two treatment groups. Donor animals in the experimental group (first wave group) received an intravaginal progesterone releasing device (Cue-Mate, Bioniche Animal Health, ON, Canada) along with PGF (0.150 mg D + cloprostenol, Bioprost-D, Biotay, Argentina) at random stages of the estrous cycle. Cue-Mates were removed 10.5 d later and a second PGF was administered at the same time, followed by GnRH (0.050 mg Lecirelina, Biosin-OV, Biotay, Argentina) 36 h later. Ovulation was expected to occur within 30 h after GnRH (day 0). On day 0 (36 h after gonadotropin-releasing hormone) donors received a new Cue-Mate, and superstimulation treatment was initiated with a total dose of 200 to 260 mg (heifers) or 320 mg (cows) NIH-FSH-P1of Folltropin-V in twice daily decreasing doses over 5 d. The PGF was administered with the last two Folltropin-V injections, and Cue-Mate devices were removed with the last Folltropin-V injection. All donors received 12.5 mg pLH (Lutropin-V, Bioniche Animal Health) 24 h after Cue-Mate removal and were AI 12 and 24 h later. Embryos were collected 7 d after pLH treatment. Donors in the Control group received a Cue-Mate and 2 mg of estradiol benzoate (EB; Bioestradiol, Biotay) and 50 mg of progesterone (Lab. Rio de Janeiro, Argentina), and superstimulation treatments were initiated 4 d later with the same dosages used in the first wave group. The PGF administration, Cue-Mate removal, AI, and embryo collections were done as those in the first wave group. Data were analyzed by ANOVA, and results are shown in Table 1. It was not possible to pass the cervix with the collection catheter in two heifers in the control group, and they were excluded from the analysis. There were no significant effects of donor category (cows v. heifers) or treatment on superovulatory response and embryo quality (P > 0.20). In conlusion, superstimulation on a synchronized first follicular wave is as efficacious as superstimulation following synchronization of follicle wave emergence with estradiol benzoate in Bonsmara cattle. Table 1. Superovulatory response (means ± SEM) in Bonsmara cows and heifers treated with Folltropin-V during the first follicular wave or 4 d after estradiol administration Bioniche Animal Health, Belleville, ON, Canada.

287 EFFECT OF FOLLICULAR WAVE SYNCHRONIZATION AND ABSENCE OF CORPUS LUTEUM ON COC RECOVERY IN Gyr (BOS TAURUS INDICUS) COWS

2010 ◽  
Vol 22 (1) ◽  
pp. 300
Author(s):  
T. Miyauchi ◽  
C. A. C. Fernandes ◽  
E. R. Oliveira ◽  
B. F. L. Alves ◽  
J. H. M. Viana
Keyword(s):  
Bos Taurus ◽  
Animal Health ◽  
Cumulus Cell ◽  
Estradiol Benzoate ◽  
Corpora Lutea ◽  
Portable Ultrasound ◽  
Follicular Wave ◽  
Main Technique ◽  
Oocyte Donors

Transvaginal guided follicle aspiration (TGFA) is the main technique used in Brazil to recover oocytes for in vitro embryo production (IVP) in bovine. Different protocols have been proposed to synchronize follicular emergence in oocyte donors, but most of them were developed for use in European breeds of cattle, which show many differences in ovarian physiology when compared with Zebu breeds. The aim of this study was to compare different protocols for preparation of Gyr (dairy zebu breed) oocyte donors. The TGFA were performed in a donor management facility located in Minas Gerais State, southeast Brazil. Pluriparous cycling Gir cows (n = 42) were used as donors. All cows underwent 3 treatments: G1 (control), no treatment before TGFA; G2, 2 mg of estradiol benzoate (EB) for follicular wave synchronization given i.m. 5 days before TGFA; and G3, norgestomet auricular implants given 9 days and 2 mg of EB plus 0.53 mg of cloprostenol given 5 days before TGFA. The interval between TGFA in the same donor was greater than 30 days. All procedures were made by the same technician, using a portable ultrasound device, disposable 19G or 20G needles, and a vacuum pressure of 80 mm Hg. The aspirated follicular fluid was collected in 50-mL Falcon tubes and sent to the laboratory for COC identification and classification under 50 × magnification. Recovered oocytes were classified according to cumulus cell layers and cytoplasm morphology. The total number of oocytes and viable COC recovered and the procedure length (min), including time spent for TGFA and laboratory manipulation, were compared. Data were evaluated by ANOVA, and means compared by Tukey’s test. A total of 126 TGFA sessions were performed, with recovery of 2,809 oocytes (20.31 ± 12.32 of COC and 14.83 ± 7.97 of viable COC per cow/session; mean ± SD). The total number of recovered oocytes and viable COC recovered were lower in G1 compared with G2 and G3 (15.18 ± 11.07 v. 21.18 ± 9.71 and 24.68 ± 9.03; and 9.53 ± 7.22 v. 16.97 ± 6.47 and 18.84 ± 8.90, respectively; P < 0.05) There was no difference (P > 0.05) between G2 and G3 on the number of oocytes or viable COCs recovered. The procedure length, however, was longer in G1 and G2 compared with G3 (49.6 ± 15.1 and 46.9 ± 13.4 v. 35.8 ± 13.1 min, respectively; P < 0.05) The shorter procedure length in G3 was probably associated with the reduced number of cows showing no corpora lutea (38/42, 90%), which resulted in reduction of bleeding and clot formation in the aspirated fluid. These results show that (1) previous follicular wave synchronization by EB can improve the number and quality of recovered oocytes; (2) the absence of corpora lutea does not increase the number of recovered COC and viable COC, but reduces the time spent in the procedure. Intervet Schering Plough Animal Health.

16 STRATEGIES OF FOLLICULAR WAVE SYNCHRONIZATION WITH ESTRADIOL BENZOATE IN GYR (BOS TAURUS INDICUS) CATTLE

2013 ◽  
Vol 25 (1) ◽  
pp. 155
Author(s):  
L. D. P. Sinedino ◽  
B. T. Gerhardt ◽  
J. A. Moura ◽  
A. P. Dourado ◽  
I. L. Goulart ◽  
...  
Keyword(s):  
Blood Sample ◽  
Estrous Cycle ◽  
Bos Taurus ◽  
Animal Health ◽  
Estradiol Benzoate ◽  
Wilcoxon Test ◽  
Second Step ◽  
Follicular Atresia ◽  
Follicular Wave ◽  
Animal Category

Physiological and behavioral differences between Bos taurus and Bos indicus can influence the response to a fixed AI protocol. The objective of this study was to examine the reduction of the usual dose of 2 mg of estradiol benzoate (EB) to 1 mg at the beginning of a fixed-time AI protocol, aiming at follicular regression. In a second step, we evaluated the effect of EB on follicle development during follicular pre-deviation and dominance. The experiment was performed at Monte Verde Farm (Uberaba, MG, Brazil). Twenty-two cows (n = 10 heifers and n = 12 nonlactating cows) underwent an estrous synchronization protocol with a progesterone-releasing intravaginal device (P4; Sincrogest®, Ouro Fino Animal Health, São Paulo, Brazil) and received 1 (G1mg, n = 11) or 2 mg (G2mg, n = 11) of EB (Sincrodiol®, Ouro Fino Animal Health), on a random day (designated Day 0). Follicular dynamics was monitored once per day by ultrasonography from Day 0 to 4 with blood sample collections. In a second step, females received 2 mg of EB on Day 3 (GD3, pre-deviation, n = 4) or Day 5 (GD5, dominance, n = 4) of the estrous cycle (Day 0 was the ovulation). Following these treatments, follicular development was monitored daily for 6 days with blood sample collections. The statistical analysis was conducted using the SAS System for Windows 2 (2003; SAS Institute Inc., Cary, NC, USA). The explanatory variables included in the statistical model were the dose of EB, animal category (cows and heifers), and their interaction. The mean test was used to compare intervals from EB treatment to follicular atresia and follicular wave emergence using ANOVA. Progesterone concentrations between groups were compared using the Wilcoxon test. Independently of animal category or stage of the estrous cycle, both EB doses (1 or 2 mg) induced follicular atresia in 2.2 ± 0.9 and 2.1 ± 1.2 days (P > 0.05), respectively. Emergence of a new follicular wave was observed, from Day 0 to 4, in 64% (7/11) of females from G1mg and in 45% (5/11) from G2mg, and the interval between treatment and follicular emergence was 3.4 ± 0.8 and 3.0 ± 1.0 days (P > 0.05), respectively. Plasma progesterone concentrations of the 22 animals increased from 2.1 ± 2.0 ng mL–1 to 7.6 ± 3.0 ng mL–1 by 24 h after the device insertion (P < 0.05), reaching peak concentration (8.0 ± 3.0 ng mL–1) by 48 h after treatment beginning, decreasing to 6.4 ± 2.5 ng mL–1 by 72 h, and remaining constant up to 96 h. Estradiol benzoate injection at follicle pre-deviation (GD3) caused follicular atresia (2.0 ± 1.4 days) and emergence of a new follicular wave in 3.7 ± 0.1 days in all animals (4/4). However, EB injection during follicle dominance (GD5) did not synchronize a new follicular wave and follicles persisted during the time of monitoring. Furthermore, EB applied at dominance hastened luteolysis in 50% (2/4) of the treated animals. In conclusion, a reduced dose of EB (1 mg) at the beginning of the protocol with P4 effectively induces follicular atresia. To synchronize a wave emergence at any stage of the estrous cycle, EB must be associated with an exogenous source of progesterone.

406 EFFECT OF DIFFERENT FOLLICLE-STIMULATING HORMONE DOSES ON SUPEROVULATORY RESPONSE OF Red Sindhi COWS

2010 ◽  
Vol 22 (1) ◽  
pp. 359
Author(s):  
B. P. Carvalho ◽  
M. R. B. Mello ◽  
J. M. Baldrighi ◽  
J. S. Campanati ◽  
R. R. C. Mello ◽  
...  
Keyword(s):  
Animal Health ◽  
Follicle Stimulating Hormone ◽  
Reproductive Potential ◽  
Estradiol Benzoate ◽  
Bovine Embryo ◽  
Treatment Groups ◽  
Adequate Dosage ◽  
Level Of Significance ◽  
Cryopreserved Embryos ◽  
Stimulating Hormone

The use of bovine embryo transfer to increase the reproductive potential of animals with high genetic merit is unquestionable. However, studies that evaluate the response to exogenous FSH stimulation in Red Sindhi cows are rare. Therefore, the objective of this study was to compare the superovulatory response of Red Sindhi cows treated with 3 different doses of FSH (Folltropin®-V, Bioniche Animal Health, Belleville, Ontario, Canada). The animals used had body condition scores ranging from 3.5 to 4.0 (1-5 scale), were between 6 and 10 years of age, and were randomly assigned to 1 of 3 treatment groups. Three doses of FSH were administered: 100 mg (n = 16); 133 mg (n = 13), and 200 mg (n = 14). The treatments were initiated on random days of the estrous cycle. On Day 0, animals received 2 mg of estradiol benzoate i.m. (Estrogin®, Farmavet, Jaboticabal, Brazil) and an intravaginal device (CIDR; InterAg, Hamilton, New Zealand) with 1.9 g of progesterone. On Day 4, donors received FSH in 8 i.m. injections that decreased in dose during 4 consecutive days. A dose of 265 μg of cloprostenol (Ciosin®, Schering-Plough, Cotia, Brazil) was given i.m. concomitantly with the fifth FSH injection. Twelve hours after the last FSH injection, donors received 25 μg of lecirelin i.m. (GnRH; Gestran Plus®, ARSA SRL, Buenos Aires, Argentina). TheAI were performed 12 and 24 h after GnRH. Seven days after the first AI, embryos were recovered and classified as described in the IETS manual. Data were evaluated using KruskalWallis test at a 5% level of significance. Ovarian ultrasonography was also performed to count the number of CL present at the time of ova/embryo collection. Results are summarized in Table 1. The number of CL and total ova/embryos was higher in donors receiving 200 mg of FSH than in those in the other groups. However, the number of transferable or cryopreserved embryos did not differ among groups. In conclusion, the dosage of 200 mg of Folltropin®-V seemed to be the more adequate dosage for this breed of cattle. Table 1.Effect of different follicle-stimulating hormone (FSH) doses on CL number, total structures, transferable embryos, and cryopreserved embryos in Red Sindhi cows (mean ± SEM) Financial support provided by FAPERJ (E26-170.529/2007).

Effect of 1 or 2 norgestomet implants inserted from days 15 to 25 after oestrus on follicular development in beef cows

1996 ◽  
Vol 1996 ◽  
pp. 133-133
Author(s):  
D.A. Adikpe ◽  
M.J. Bryant
Keyword(s):  
Pregnancy Rate ◽  
False Positive ◽  
Luteal Phase ◽  
Follicular Development ◽  
Beef Cows ◽  
Beef Heifers ◽  
Follicular Wave ◽  
Ovulatory Follicle

Controlling the timing of ovulation in cows that fail to conceive after insemination would provide a further opportunity for scheduled rebreeding in a group of cows to save time and optimise results. The ear implant Crestar containing the synthetic progestagen norgestomet provides a means of achieving this control (Sinclair et al., 1992; Lowman et al., 1994). Removing the implant on day 25 after oestrus results in less false positive pregnancy diagnoses than removal on day 21 with the implant in place for nine/ten days. However, treatment of beef heifers with a norgestomet implant towards the end of luteal phase to control oestrus and ovulation is associated with development of a persistent ovulatory follicle and reduced pregnancy rate (Mihm et al., 1994). The objective of this study was to determine the effects of treating beef cows with one or two norgestomet implants on the development of the dominant ovulatory follicle of the second follicular wave.

404 SUPEROVULATORY RESPONSE IN BEEF DONORS TREATED DURING THE FIRST FOLLICULAR WAVE OR FOUR DAYS AFTER PROGESTERONE AND ESTRADIOL ADMINISTRATION

2010 ◽  
Vol 22 (1) ◽  
pp. 358 ◽  
Author(s):  
D. Carballo Guerrero ◽  
A. Tríbulo ◽  
R. Tríbulo ◽  
H. Tríbulo ◽  
G. A. Bó
Keyword(s):  
Estrous Cycle ◽  
Animal Health ◽  
Estradiol Benzoate ◽  
Control Group ◽  
Wave Groups ◽  
Follicular Wave ◽  
Estrus Detection ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Although we have previously shown that ovarian superstimulation during the first follicular wave resulted in a successful response (Carballo Guerrero D et al. 2009 Reprod. Fertil. 21, 242), the current protocol needs to be optimized in order to be used in the field. Therefore, an experiment was designed to simplify this treatment and to compare it with the traditional superstimulation protocol using progesterone and estradiol. Simmental cows (n = 14) were subjected to 3 superstimulation treatments (2 first wave groups and 1 control group) in a crossover design (i.e. all cows received the 3 treatments and all treatments were represented on each collection day). Cows in Group 1 received a progesterone-releasing device (Cue-Mate®, Bioniche Animal Health, Belleville, Ontario, Canada) along with 0.150 mg of D + cloprostenol (PGF; Bioprost-D®, Biotay, Buenos Aires, Argentina) at random stages of the estrous cycle. A second PGF was injected 5 days after Cue-Mate® insertion, followed by GnRH (0.050 mg of lecirelin; Biosin-OV®, Biotay) 36 h later (i.e. 7 days after Cue-Mate® insertion). Based on previous studies, ovulation was expected to occur 30 to 36 h later. Therefore, superstimulation treatments were initiated 36 h after GnRH (Day 0), with a total dose of 400 mg NIH-FSH-P1 of Folltropin®-V (Bioniche Animal Health) in twice-daily decreasing doses over 4 days. Prostaglandin was administered with the last 2 Folltropin®-V injections and Cue-Mate® devices were removed with the last Folltropin®-V injection. Cows received 12.5 mg of porcine LH (Lutropin®-V, Bioniche Animal Health) 24 h after Cue-Mate® removal and were AI 12 and 24 h later. Ova/embryos were collected 7 days after porcine LH and evaluated following IETS recommendations. Cows in Group 2 were treated similarly to those in the Group 1, except they did not receive the second PGF injection 5 days after Cue-Mate® insertion (thus eliminating the need to handle animals on that day). Finally, cows in Group 3 [estradiol benzoate (EB)+P4 control group] received a Cue-Mate® plus 2.5 mg of EB (Bioestradiol®, Biotay) and 50 mg of progesterone (P4; Lab., Rio de Janeiro, Argentina) at random stages of their estrous cycle. Superstimulation treatments were initiated 4 days later (Day 0) following the same protocol used in Group 1. Data were transformed to square root and analyzed by ANOVA. Mean (± SEM) numbers of ova/embryos collected, fertilized ova, and transferable embryos did not differ among groups (12.9 ± 2.0, 9.8 ± 1.7, and 6.6 ± 1.2; 11.5 ± 1.7, 9.3 ± 1.5, and 7.7 ± 1.6; and 14.5 ± 2.8, 9.4 ± 2.3, and 6.8 ± 1.7 for Groups 1, 2, and 3, respectively). In conclusion, data demonstrated that superstimulation during the first follicular wave can be successfully used in groups of randomly cycling donors without the need for estrus detection or estradiol to synchronize follicular wave emergence. The protocol is easy to follow and embryo production is comparable to that of the estradiol and progesterone protocol.

Influence of trenbolone acetate, zeranol and oestradiol-17β implantation on growth performance and reproductive function in beef heifers

1991 ◽  
Vol 52 (2) ◽  
pp. 249-253 ◽  
Author(s):  
A. Zarkawi ◽  
H. Galbraith ◽  
J. S. M. Hutchinson
Keyword(s):  
Growth Performance ◽  
Short Duration ◽  
Untreated Control ◽  
Follicular Development ◽  
Reproductive Function ◽  
Equal Treatment ◽  
Beef Heifers ◽  
Trenbolone Acetate ◽  
Treatment Groups ◽  
Ovarian Cyclicity

ABSTRACTTwenty-four Hereford ♂ × Friesian ♀ heifers were divided into four equal treatment groups and given subcutaneous ear implants as appropriate 14 days after prostaglandin treatment for the induction of synchronized cycles. Subsequently, they were observed for 75 days. One group was an untreated control, one was given 300 mg trenbolone acetate, one 36 mg zeranol and one 45 mg oestradiol-176. Growth and ovarian cyclicity, assessed by periodic progesterone measurement, were monitored. Trenbolone acetate-treated heifers grew faster (P < 0·05) than other groups which did not differ significantly. Trenbolone acetate shortened the oestrous cycle in which treatment was started in two of five heifers and lengthened it in two others. Subsequent cycles were either suppressed or of short duration. Zeranol and oestradiol-176 treatment had little effect on ovarian cyclicity apart from a small increase in the number of short cycles. It is concluded that, at the doses used, trenbolone acetate suppresses mechanisms leading to ovulation or pre-ovulatory follicular development.

Sign in / Sign up

Export Citation Format

Share Document