419 OVARIAN ULTRASONOGRAPHY TO ANALYZE FOLLICULAR DYNAMICS DURING SUPEROVULATORY TREATMENT IN RED DEER (CERVUS ELAPHUS) HINDS

2010 ◽  
Vol 22 (1) ◽  
pp. 366
Author(s):  
J. P. Soler ◽  
N. Mucci

Inconsistency of the superovulatory responses of donor hinds has been a general feature of all red deer MOET programs (Asher GW et al. 2000 Anim. Reprod. Sci. 59, 61-70). The development of the techniques has been by trial and error as there is usually a lack of basic information on which to base MOET protocols (Fennessy PF et al. 1994 Theriogenology 41, 133-138). The objective of this study was to understand follicle development during a superovulatory treatment in order to improve ovulation rates and quantity of transferable embryos produced. During the breeding season, 10 mature (3-5 years old) red deer hinds were synchronized receiving an intravaginal sponge containing 100 mg of medroxiprogesterone acetate for 13 days, with device replacement on Day 11. Four days prior to the beginning of the FSH treatment, 0.5 mg of estradiol benzoate (Syntex SA, Buenos Aires, Argentina) was given i.m. to synchronize the follicular wave. Superovulation was conducted with a total dose of 120 mg of NIH-FSH-P1 (Folltropin®-V, Bioniche Animal Health, Belleville, Ontario, Canada) given i.m. in 4 equal doses of 30 mg every 24 h, from Day 11 to 14. Forty-eight hours after sponge withdrawal, 0.84 mg of buserelin acetate (Receptal®, Intervet, Boxmeer, the Netherlands) was injected i.m. to stimulate and synchronize ovulations. Ovarian scanning was performed by transrectal ultrasonography using a multifrequency linear transducer (Tringa Linear, Esaote Pie Medical, Genoa, Italy) on Days -1, 0, 1, 2, 3, 4, 5, and 6, Day 0 being the day of sponge withdrawal. The diameters of all follicles ≥3 mm were measured and their 3-dimensional position recorded to determine growth and ovulation. The average ovulation rate was 10.8 ± 1.6. The distribution of ovulations was 9.3, 31.5, 24.1, 22.2, 9.2, and 3.7% at 24, 48, 72, 96, 120, and 144 h after sponge withdrawal, respectively. The proportion of follicles that did not ovulate during the period of this study was 16.9%. The proportion of ovulated follicles according to their diameter was 9.3, 68.5, and 22.2% for 3 mm, 4 to 5 mm, and ≥6 mm, respectively, and were during the 24- to 96-h period for the first 2 follicles categories and after 96 h for the last category. This study showed a great variability of ovulations in the superovulatory protocols routinely used in red deer donor hinds. Improvement of the hormone treatment to induce a greater degree of ovulation synchrony (within 72 h after progesterone device withdrawal) would increase the fertilization rates and the quantity of transferable embryos produced in red deer MOET programs. Table 1.Mean (±SEM) ovulation rate and number of follicles recorded at each ultrasonography day before and after sponge withdrawal

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

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.


2013 ◽  
Vol 25 (1) ◽  
pp. 155
Author(s):  
L. D. P. Sinedino ◽  
B. T. Gerhardt ◽  
J. A. Moura ◽  
A. P. Dourado ◽  
I. L. Goulart ◽  
...  

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.


2010 ◽  
Vol 22 (1) ◽  
pp. 358 ◽  
Author(s):  
D. Carballo Guerrero ◽  
A. Tríbulo ◽  
R. Tríbulo ◽  
H. Tríbulo ◽  
G. A. Bó

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.


2013 ◽  
Vol 25 (1) ◽  
pp. 306
Author(s):  
M. E. F. Oliveira ◽  
C. C. D'Amato ◽  
C. S. Oliveira ◽  
F. F. P. C. Barros ◽  
A. P. Perini ◽  
...  

This study was designed to investigate if the time of onset of FSH treatment [near the emergence of first or last follicular wave on progesterone (P4) protocol] influenced the superovulatory response and embryo yield in Santa Ines ewes during breeding season. Days of emergence of the follicular waves were defined in a previous study that evaluated the follicular dynamic in oestrus synchronization treatments (Oliveira et al. 2011 Acta Sci. Vet. 40). We observed emergence of the first and last follicular wave on 5.69 ± 0.42 and 11.25 ± 0.39 days of protocol, respectively. Twenty Santa Ines ewes were submitted to 2 superovulatory protocols according to the time that FSH treatments were initiated (G-first wave, n = 10; G-last wave, n = 10). On Day 0, all ewes received a P4 device (CIDR®; Pfizer Animal Health, New York, NY, USA) and injection of 37.5 µg of d-cloprostenol, IM. The FSH treatments started on Day 6 and Day 11 of protocol for G-first and G-last, respectively. The superovulatory regimen consisted of 8 IM injections of pFSH administrated twice daily (40, 40, 30, 30, 20, 20, 10, and 10 mg of pFSH). The P4 device was removed on Day 8 and Day 13 for G-first and G-last, respectively. At these times, all ewes received another injection of 37.5 µg of d-cloprostenol and a dose of 200 IU of eCG. During 4 days after the P4 device removal, ewes were mated by a fertile ram. Embryo collections were accomplished 7 days after CIDR withdrawal. The ovaries were evaluated by ultrasonography (3 times daily, during the mating period) and laparotomy (concomitantly with embryo collection). The superovulatory response was observed by classified by score: 0 = 4 or fewer corpora lutea (CL); 1 = between 5 and 10 CL; and 2 = 11 or more CL. Data were analysed by GLIMMIX using SAS software (SAS Institute Inc., Cary, NC, USA). All donors from G-first had superovulatory response classified as score 2, whereas 60% of ewes from G-last were classified as score 2, 20% as score 1, and 20% as score 0 (P < 0.05). There were effects between treatments (P < 0.05) for ovulation rate (G-first: 97.9 ± 1.4% v. G-last: 88.5 ± 4.4%) and number of ovulations (G-first: 17.0 ± 2.3 v. G-last: 12.5 ± 2.6). The numbers of luteinized unovulated follicles were 0.7 ± 0.5 for G-first and 1.2 ± 0.4 for G-last (P > 0.05). There was no difference between G-first and G-last (P > 0.05) in the rate of ova/embryos recovered (54.9 ± 5.7% v. 49.3 ± 8.5%), mean number of ova/embryos recovered (9.0 ± 1.4 v. 6.3 ± 1.1), number of viable embryos (3.8 ± 1.5 v. 3.4 ± 0.8), or viability rate (40.3 ± 10.8 v. 53.4 ± 12.1). In conclusion, the FSH treatment started near the emergence of the first follicular wave of progesterone protocol in Santa Ines ewes during the breeding season resulted in a higher superovulatory response than that started near the last follicular wave; however, no improvements in embryo yield were observed. Financial support: FAPESP.


2005 ◽  
Vol 17 (2) ◽  
pp. 160
Author(s):  
M. Martínez ◽  
M. Caccia ◽  
M. Colazo ◽  
G. Bó ◽  
J. Kastelic ◽  
...  

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.


2008 ◽  
Vol 20 (1) ◽  
pp. 152 ◽  
Author(s):  
C. M. Barros ◽  
A. C. Z. Barcelos ◽  
L. M. Gouvêa ◽  
M. Meneghel ◽  
D. S. Barcelos ◽  
...  

In the present study, the superstimulatory protocol coined P-36 (Nogueira et al. 2007 Theriogenology 67, 655–660) was modified in order to test if replacement of pFSH by eCG in the last day of superstimulatory treatment would improve follicular growth, ovulation rate, and embryo yield. Nelore cows (n = 20) were randomly allocated to two groups: P-36/LH48 and P-36/LH48/eCG. Each female received both treatments in a cross-over design; the first experimental period was in October (Spring 2006, both groups) and the second in February (Summer 2007, both groups). At a random stage of the estrous cycle (D0), animals received a progesterone intravaginal device (DIB�, 1.0 g; Syntex S.A., Buenos Aires, Argentina) plus estradiol benzoate (EB, Estrogin�, 2.5 mg IM; Farmavet, Sao Paulo, Brazil). The animals were superstimulated with pFSH (Folltropin-V�, Bioniche Animal Health, Ontario, Canada), administered twice daily in decreasing doses of 53.2, 39.9, 26.6, and 13.3 mg (total dose = 133 mg), from Day 5 to Day 8, except the P-36/LH48/eCG group, where the last two doses of pFSH were replaced by two doses (200 IU) of eCG (Novormon�, Syntex, Buenos Aires, Argentina). All cows were treated with D-cloprostenol (150 µg IM;Veteglan�, Calier, Barcelona, Spain) on Day 7 at 7:00 h, and DIBs� were removed 36 h after PGF2alpha administration. On Day 9, ovulation was induced by pLH administration (Lutropin�, 12.5 mg IM; Bioniche Animal Health) at 7:00 h. The animals were inseminated at 12 and 24 h after pLH administration, without estrus detection. Embryos were recovered on Day 16 or 17. Data were analyzed by ANOVA (Proc Mixed, SAS; SAS Institute, Inc., Cary, NC, USA), and the difference was considered significant when P < 0.05 or not significant (NS). Results for animals from groups P-36/LH48 and P-36/LH48/eCG were compared and are reported in this order. The number of follicles with diameter larger than 6 mm at the time of pLH administration (15.25 � 2.06 and 21.05 � 2.76; P < 0.01), the ovulation rate observed up to 48 h after pLH administration (77.7 � 5.6 and 83.9 � 2.6; NS), the total number of oocytes/embryos recovered (6.65 � 1.18 and 10.0 � 1.48; P < 0.03), the number of embryos recovered (6.05 � 1.24 and 8.35 � 1.30; NS), and the number of viable embryos (5.10 � 1.10 and 7.30 � 1.20; NS) are reported. The embryo quality (excellent, good, fair, and poor) was NS among groups P-36/LH48 and P-36/LH48/eCG. It is concluded that replacement of pFSH by eCG, on the last day of the superstimulatory protocol P-36, was beneficial since there was a significant increase in the number of follicles (>6 mm at the time of pLH administration) and the total number of structures recovered. Experiments are in progress to confirm these beneficial effects of eCG on the P-36 protocol. This work was supported by FAPESP (Sao Paulo, Brazil). A. C. Z. Barcelos received a fellowship from CAPES (Brazil).


2007 ◽  
Vol 19 (1) ◽  
pp. 309
Author(s):  
C. M. Martins ◽  
H. Ayres ◽  
J. R. S. Torres-Junior ◽  
A. H. Souza ◽  
G. A. Bó ◽  
...  

In embryo transfer programs, 2 inseminations per superstimulated donor are usually recommended. Based on studies of follicular dynamics in Bos indicus donors (Baruselli et al. 2006 Theriogenology 65, 77–88), we tested the hypothesis that a single fixed-time AI (FTAI) at 16 h after pituitary luteinizing hormone (pLH) treatment is as efficacious as 2 FTAI at 12 and 24 h after the pLH treatment. Suckling Nelore cows (n = 10), 60 � 12 days postpartum, were equally distributed in 2 experimental groups: G-1TAI vs. G-2TAI, in a crossover design. All animals received an intravaginal progesterone device (DIB; Syntex S.A., Buenos Aires, Argentina) and 2 mg of estradiol benzoate (IM, Ric Be; Syntex) at random stages of the estrous cycle (Day 0). Superstimulatory treatments started on Day 4 with pFSH (133 mg; Folltropin-V; Bioniche Animal Health Canada, Inc., Belleville, Ontario, Canada) in 8 decreasing doses, given IM 12 h apart. On Day 6, all cows received 2 (AM and PM) treatments of 0.15 mg of d-cloprostenol (Prolise; Syntex). The DIB devices were removed 36 h after the first PGF2� injection. The pLH treatment (25 mg IM; Lutropin-V; Bioniche) was given 48 h after the first PGF2� treatment (12 h after the last pFSH treatment). In the G-2TAI group, all cows received 2 inseminations (12 and 24 h after the pLH). Cows in the G-1TAI group received a single insemination (16 h after the pLH). All inseminations were done with the same batch of semen from a single bull. Ultrasound examinations (PIE Medical Scanner 200; Pie Medical Equipment, Maastricht, The Netherlands) were performed every 12 h from 0 to 72 h after pLH treatment to evaluate the number of ovulatory follicles (&lt;8 mm), the ovulation rate, and the time of ovulation. Variables were analyzed by ANOVA and chi-square test. The homogeneity of the variances (distribution of ovulations) was analyzed by Bartlett&apos;s test. Conclusions were based on a 5% level of significance. The results for G-1TAI and G-2TAI were, respectively: number of follicles &gt;8 mm at the time of pLH administration (16.2 � 1.4 vs. 14.8 � 1.2; P &gt; 0.05), ovulation rate (63.8 � 3.8% vs. 64.2 � 4.3%; P &gt; 0.05), interval from the first to the last ovulation (32.4 � 1.8 vs. 33.6 � 1.6 h; P &gt; 0.05), total ova/embryos (8.2 � 0.9 vs. 7.2 � 0.8; P &gt; 0.05), Grade 1 embryos (2.0 � 0.5 vs. 2.3 � 0.4; P &gt; 0.05), transferable embryos (Grades 1, 2, and 3) (4.3 � 0.7 vs. 4.2 � 0.6; P &gt; 0.05), freezable embryos (Grades 1 and 2) (2.9 � 0.6 vs. 2.8 � 0.4; P &gt; 0.05), unfertilized ova (0.6 � 0.2 vs. 0.8 � 0.2; P &gt; 0.05), and degenerated embryos (3.3 � 0.9 vs. 2.2 � 0.3; P &gt; 0.05). These results suggest no significant differences in embryo production between superstimulated Nelore donors inseminated once or twice by fixed time following administration of pLH. This work was supported by Tecnopec, Brazil.


1994 ◽  
Vol 6 (2) ◽  
pp. 269 ◽  
Author(s):  
AP Flint ◽  
HN Jabbour ◽  
AS Loudon

The prostaglandin F2 alpha analogue cloprostenol stimulates ovarian secretion of oxytocin in red deer hinds and Pere David's deer hinds, as in cattle and sheep, but the response of the uterus to administered oxytocin has not been studied in deer. In the present experiment, oxytocin administered intravenously caused an increase in circulating concentrations of 13,14-dihydro-15-keto prostaglandin F2 alpha from 186 +/- 35 to 404 +/- 34 pmol L-1 within 5 min; concentrations in saline-treated hinds were unchanged (150 +/- 12 and 164 +/- 12 pmol L-1 before and after treatment respectively). This suggest that in red deer as in other ruminants, a positive feedback relationship between the corpus luteum and the uterus may operate to stimulate luteolytic episodes of prostaglandin F2 alpha.


2008 ◽  
Vol 20 (1) ◽  
pp. 226 ◽  
Author(s):  
D. Carballo Guerrero ◽  
A. Tribulo ◽  
R. Tribulo ◽  
H. Tribulo ◽  
G. A. Bo

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.


1998 ◽  
Vol 244 (1) ◽  
pp. 123-134 ◽  
Author(s):  
A. M. Long ◽  
N.P. Moore ◽  
T. J. Hayden

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