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.

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.

13 EFFECTS OF PLASMA PROGESTERONE CONCENTRATIONS ON LH RELEASE AND OVULATION IN BEEF CATTLE GIVEN GnRH

2006 ◽  
Vol 18 (2) ◽  
pp. 115
Author(s):  
H. Davis ◽  
M. Colazo ◽  
M. Rutledge ◽  
J. Small ◽  
J. Kastelic ◽  
...  
Keyword(s):  
Animal Health ◽  
Beef Cows ◽  
Dominant Follicle ◽  
Plasma Progesterone ◽  
Lactating Cows ◽  
Significant Difference ◽  
Prostaglandin F ◽  
Pfizer Animal Health ◽  
Lh Release ◽  
To Receive

Two experiments were conducted to determine the effects of plasma progesterone (P4) concentrations on LH release and ovulation in beef heifers and lactating beef cows given gonadotropin-releasing hormone (GnRH). Previously autoclaved, once-used CIDR inserts (Colazo et al. 2004 Anim. Reprod. Sci. 81, 25-34) were used for experimental purposes to induce differential plasma progesterone concentrations. In Experiment 1, postpubertal heifers received 25 mg of dinoprost i.m. (prostaglandin F (PGF); Lutalyse; Pfizer Animal Health, Montreal, Quebec, Canada). On Day 4 (estrus = Day 0), heifers were randomly assigned (10/group) to receive no treatment (control) or 1 or 2 autoclaved once-used CIDR (Pfizer Animal Health) inserts (1CIDR and 2CIDR, respectively). On Day 5, heifers in the 1CIDR group were given PGF twice 12 h apart. On Day 6, all heifers received 100 �g of GnRH i.m. (Cystorelin; Merial Canada, Inc., Victoriaville, Quebec, Canada). Once daily on Days 4 to 9, a blood sample was collected and ultrasonography was performed. On Day 6, heifers in the control (3.0 � 0.4 ng/mL; mean � SD) and 1CIDR groups (3.0 � 0.3 ng/mL) had lower (P < 0.01) plasma progesterone concentrations than those in the 2CIDR group (5.7 � 0.4 ng/mL). However, the diameter of the dominant follicle was larger (P < 0.001) in heifers in the control and 1CIDR groups than in the 2CIDR group (12.1 � 1.0, 11.5 � 0.7, and 10.1 � 0.7 mm, respectively). More (P < 0.01) heifers ovulated in response to GnRH in the control and 1CIDR groups than in the 2CIDR group (10/10, 9/10, and 3/10, respectively). In Experiment 2, ultrasound-guided follicular ablation (FA) was performed (to synchronize ovarian follicular wave emergence) 4 to 6 days after estrus in 20 postpubertal heifers and 20 mature lactating cows. Cattle were randomly and equally assigned to receive an autoclaved, once-used CIDR, either with no further treatment (High-P4) or with two PGF treatments 12 h apart (Low-P4) given after FA. All cattle received 100 �g of GnRH either 6 days after FA or the day after the dominant follicle reached 9 mm in diameter. Ultrasonography was performed daily (from 4 days after FA to ovulation or to 3 days after GnRH treatment). In three cows and three heifers per group, blood samples were collected every 30 min for 12 h after GnRH. The dominant follicle at GnRH treatment was larger in cows than heifers (11.0 � 1.1 vs. 10.3 � 0.9 mm, respectively; P = 0.05) and tended to be smaller in the High-P4 group vs. the Low-P4 group (10.3 � 1.0 vs. 11.0 � 1.0 mm; P = 0.06). Ovulatory response was not different (P = 0.9) between heifers (77.7%) and cows (78.9%), but combined for heifers and cows, was lower in High-P4 vs. Low-P4 cattle (61.1 vs. 94.7; P < 0.01). The GnRH-induced LH surge did not differ (P = 0.23) between cows and heifers, but it was lower and of shorter duration (P < 0.001) in the High-P4 group than in the Low-P4 group. In summary, higher plasma P4 concentrations resulted in decreased LH release and the proportion of cattle ovulating in response to GnRH treatment. There was no significant difference between heifers and cows in LH release or ovulatory response.

295 SUPEROVULATORY RESPONSE IN COWS FOLLOWING SYNCHRONIZATION OF FOLLICLE WAVE EMERGENCE WITH ESTRADIOL AT DIFFERENT STAGES OF THE ESTROUS CYCLE

2008 ◽  
Vol 20 (1) ◽  
pp. 227
Author(s):  
A. Garcia Guerra ◽  
G. A. Bó ◽  
J. Villarreal ◽  
G. M. Brogliatti
Keyword(s):  
Estrous Cycle ◽  
Buenos Aires ◽  
Animal Health ◽  
Ovarian Response ◽  
Buenos Aires Province ◽  
Transfer Program ◽  
Dominant Follicle ◽  
Follicular Wave ◽  
Significant Difference ◽  
Group 2

Ovarian asynchrony and variability in response to superstimulation remain the most limiting factors in any embryo transfer program (Armstrong D 1993 Theriogenology 39, 7–24). Ovarian response can be increased and less variable if superstimulatory treatment is started at the time of follicular wave emergence (Bö GA et al. 1995 Theriogenology 43, 31–40). A combination of progesterone (P4) and estradiol have been used to synchronize follicular wave for superstimulation. A retrospective analysis was done to compare the ovarian response, superovulatory response and embryo production of cows in Argentina that received progesterone and estradol prior to superstimulation at different stages of the estrous cycle. This research was carried out using different breed of donors (n = 584, 88% Angus) during the last 4 years in Buenos Aires province, Argentina. Heat detection was performed twice a day. At random stages of the estrous cycle, donors received an intravaginal progesterone device (DIB; Syntex, Buenos Aires, Argentina), 2 mg of estradiol benzoate and 50 mg of progesterone (Syntex, Buenos Aires, Argentina) IM on the same day. On day 4 after DIB insertion, superestimulatory treatment was initiated on a decreasing dose regimen of FSH (Pluset; Callier, Spain, or Folltropin, Bioniche Animal Health Inc., Belleville, Ontario, Canada) as IM injections every 12 h over 4 d. On day 6, DIBs were removed, and cows received two doses of 2 mL of cloprostenol 12 h apart. At heat detection, all donors received a dose of 2 mL of GnRH (Dalmarelin; Fatro Von Franken, Buenos Aires, Argentina) by IM injection and were inseminated 12 and 24 h later. Seven days later, embryo collection was performed and ovarian response was evaluated as number of CL + unovulated follicles by transrectal ultrasound using a 7.5-MHz transducer (Pie Medical, Maastricht, the Netherlands). Ova/embryos were evaluated and classified according to the IETS manual. Donors were assigned to receive DIB and estradiol during the following stages of the cycle: group 1: between days 4 and 7 post-estrus (dominant follicle period), group 2: between days 8 and 12 post-estrus (emergence of the second follicular wave), and group 3: between days 13 and 21 post-estrus (dominant follicle of the second wave). Kruskal-Wallis test was used to compare variables among groups, and results are shown in Table 1. Ovarian response as CL + unovulated follicles and number of ovulations were significantly different among groups (P < 0.05). However, there was no significant difference in the number of fertilized ova or transferable embryos. Nevertheless, numeric differences that show that group 2 (started between days 8 and 12 post-estrus) was always superior for all variables. In conclusion, data suggest that estradiol may be more effective in synchronizing follicle wave emergence for superstimulation during the mid-part of the estrous cycle. Table 1. Superovulatory response in cows in which follicle wave emergence was synchronized with estradiol at different stages of the estrous cycle (mean ± SD) Research supported by Centro Genetico Bovino Eolia S.A.

252 THE ROLE OF INSULIN-LIKE GROWTH FACTOR 1 (IGF-1) IN DEVELOPMENT OF AN ESTROGEN-ACTIVE DOMINANT FOLLICLE DURING THE FIRST FOLLICULAR WAVE POSTPARTUM IN DAIRY COWS

2007 ◽  
Vol 19 (1) ◽  
pp. 242
Author(s):  
C. Kawashima ◽  
N. Sudo ◽  
C. Amaya Montoya ◽  
E. Kaneko ◽  
M. Matsui ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Repeated Measures ◽  
Follicular Development ◽  
High Plasma ◽  
T Test ◽  
Dominant Follicle ◽  
High Concentration ◽  
Follicular Wave ◽  
Follicle Diameter ◽  
High Level

Recent studies have shown that IGF-1 is a crucial factor for ovarian follicular development in mammals. In postpartum (pp) dairy cows, plasma IGF-1 and estradiol (E2) levels in ovulatory cows at the first follicular wave pp are higher than in anovulatory cows. However, the plasma IGF-1 profile in an ovulatory or anovulatory dominant follicle (DF), which have different E2 production, at the first follicular wave pp have not yet been elucidated. Thus, we investigated the changing profile of plasma IGF-1 levels during first follicular wave pp. In 22 multiparous Holstein cows, blood samples were obtained 2 times/week from 4 weeks prepartum to 3 weeks pp, and the first follicular wave was monitored by ultrasound 2 times/week from 7 days pp to ovulatory phase. Detailed IGF-1 profiles in blood were determined during DF growth and maturation 4 times/day from 10 days pp to 7 days after the first ovulation in 5 ovulatory cows and to 20 days pp in 4 anovulatory cows; the data were analyzed by repeated measures ANOVA, and Student&apos;s t-test. There was no interaction between groups and time within the prepartum or the pp period. The ovulatory cows (n = 13/22) with an estrogen-active dominant (EAD: high plasma E2 level with peak) follicle showed higher IGF-1 levels than anovulatory cows (n = 9/22) with an estrogen-inactive dominant (EID: low plasma E2 level without peak) follicle during the prepartum (117 � 8 vs. 91 � 5 ng mL-1; P &lt; 0.05) and the pp (91 � 4 vs. 64 � 4 ng mL-1; P &lt; 0.001) period. Especially noteworthy, during the first follicular wave pp in ovulatory cows, the plasma IGF-1 levels were maintained at a high level until E2 levels increased, followed by an LH surge. We observed that the EAD follicle in ovulatory cows ovulated. To further examine the IGF-1 system in the intra-follicular environment, we used the EAD and EID follicles from ovaries of dairy cows obtained at a slaughterhouse. The EAD and EID follicles were classified on the basis of follicle diameter and E2 concentrations in follicular fluid (FF). The significant differences of factors between EAD and EID were analyzed by Student&apos;s t-test. The expression of IGF-1 mRNA was not detected in follicular cells in either EAD and EID, suggesting that IGF-1 in FF is mainly derived from liver. The free IGF-1 levels in FF in EAD (4.8 � 0.5 ng mL-1) were higher than those in EID (2.7 � 0.1 ng mL-1; P &lt; 0.05). In addition, the expression of type 1 IGF receptor (IGFR-1) mRNA in EAD was higher than hat in EID (P &lt; 0.0001). From the results of the present study, it is apparent that the EAD follicle during the first follicular wave pp in ovulatory cows sufficiently expressed IGFR-1, and a liver-derived IGF-1 stimulates E2 production in the follicle to ovulate. In conclusion, our data suggest that a high concentration of IGF-1, secreted from the liver, during the peripartum period may be one of important factors for the appearance of an ovulatory follicle during the first follicular wave pp cows.

36 FOLLICULAR DYNAMICS IN PROLIFIC SHEEP: PGF-BASED ESTRUS SYNCHRONIZATION

2010 ◽  
Vol 22 (1) ◽  
pp. 176
Author(s):  
L. Proctor ◽  
D. Tutt ◽  
D. Olliver ◽  
S. Galloway ◽  
J. L. Juengel ◽  
...  
Keyword(s):  
Animal Health ◽  
T Test ◽  
Corpora Lutea ◽  
Follicular Wave ◽  
Follicle Diameter ◽  
Array Transducer ◽  
Significant Difference ◽  
Preovulatory Follicles ◽  
Student’S T ◽  
Follicular Dynamics

A study was designed to compare the effect of a prostaglandin-based synchronization protocol on ovarian follicular dynamics in sheep with the FecB (Booroola) mutation. Forty dry Romney sheep (57.6 ± 7.3 kg; 6.1 ± 1.1 years) were randomly selected from both Invermay Booroola (BB; n = 20) and commercial (non-FecB carriers, ++; n = 20) flocks. All ewes had their estrous cycles synchronized with 2 i.m. injections of PGF (150 μg of cloprostenol, Estrumate, Schering-Plough Coopers Animal Health Ltd., New Zealand) administered 7 days apart. Ewes were monitored by transrectal ultrasonography (Aloka 900-SSD and a 7.5-MHz linear-array transducer, Aloka, Tokyo, Japan) daily from Day -2 to the day of ovulation. Data were analyzed by Student’s t-test or Wilcoxon Rank Sum test. Variances were compared with Barlett’s test. Paired t-test compared the number of preovulatory follicles in each genotype after PGF treatments and intervals from PGF to ovulation after PGF. Data are presented as mean (± SEM). The number of corpora lutea (CL) and total CL area at the time of the first and second PGF treatment were 4.4 ± 0.6; 5.7 ± 1.4 and 672.1 ± 133.5 mm2; 999.0 ± 145.9 mm2 in the BB and 2.1 ± 0.2; 2.1 ± 0.5 and 342.3 ± 60.7 mm2; 401.3 ± 68.6 mm2 in ++ ewes, respectively. These 2 variables were higher (P < 0.01) at both PGF injections in the BB than in the ++ ewes, except the CL area at the time of first PGF treatment (P = 0.15). The largest follicle diameter at the time of the first and second PGF treatments was smaller (P < 0.003) in BB (4.1 ± 0.3 mm; 3.5 ± 0.2 mm) than in ++ (5.3 ± 0.3 mm; 5.8 ± 0.1 mm) ewes. The median and mean number of follicles that ovulated after the first and second PGF treatment were higher (P < 0.0001) in BB (6 & 7; 5.7 ± 0.3; 6.9 ± 0.3; difference = 1.2 ± 0.4; P < 0.003) than in the ++ (2 & 2; 2.1 ± 0.1; 2.1 ± 0.1) sheep. The luteal area at the time of first and second PGF in both BB and ++ did not differ (P = 0.3). The intervals from the first and second PGF to the respective ovulations did not differ (P > 0.61) between BB (3.4 ± 0.2; 3.0 ± 0.3d) and ++ (3.5 ± 0.2d; 3.0 ± 0.1d) ewes. However, interval from the second PGF to ovulation was more variable (P = 0.002) in the BB than in the ++ ewes. Data of both groups were combined and a mean significant difference of 0.6 ± 0.2d (P < 0.003) was found between the first and second PGF-to-ovulation intervals. The interval from the first PGF to emergence of the next follicular wave was shorter (P < 0.02) and more variable (P < 0.03) in the BB (2.7 ± 0.4d) than in the ++ (3.5 ± 0.2 d) group. Preovulatory follicles were smaller in Booroola, but higher in number, than in ++ ewes, whereas the luteal area was similar. Within the BB ewes, the higher number of follicles that ovulated after the second PGF than after the first injection may be due to a higher follicular response to an elevated rebound in circulating FSH after the first PGF. A high number of growing follicles of the first follicular wave may also have contributed to this event. These findings warrant further research aimed at the study of the interaction between FSH and follicle dynamics in estrus synchronized sheep carrying the FecB mutation.

418 EFFECT OF SUPEROVULATION INITIATED AT FOLLICULAR WAVE EMERGENCE IN Santa Inês EWES

2010 ◽  
Vol 22 (1) ◽  
pp. 366
Author(s):  
B. D. M. Silva ◽  
T. A. S. N. Silva ◽  
L. Dalcin ◽  
C. M. Lucci ◽  
J. P. Neves
Keyword(s):  
Total Dose ◽  
Buenos Aires ◽  
Ovarian Response ◽  
Corpora Lutea ◽  
Dominant Follicle ◽  
Treatment Groups ◽  
Follicular Wave ◽  
Preliminary Study ◽  
Santa Inês ◽  
Fresh Semen

Superovulation in ewes has been a source of many studies aimed at obtaining high superovulatory response and number of viable embryos recovered. In a protocol called Day 0, superovulatory treatment was initiated at the time of wave emergence in the absence of a dominant follicle (Menchaca A et al. 2002 Theriogenology 58, 1713-1721). The aim of this study was to compare ovarian response and number of embryos recovered after treatment between ewes treated with a Day 0 protocol and those treated with a traditional protocol. Santa InÊs ewes (n= 18) between 2 and 5 years old were randomly distributed into 2 superovulation treatment groups: traditional protocol and Day 0 protocol. Each treatment was repeated twice in a crossover model. The traditional protocol consisted of the intravaginal insertion of a sponge containing 60 mg of medroxiprogesterone acetate (MAP; Progespon®, Tecnopec, São Paulo, Brazil) for 14 days, which was replaced on Day 7, followed by 150 μg of cloprostenol (Prolise®, Tecnopec) i.m. On Day 12, FSH (Folltropin®-V, Bioniche, Belleville, Ontario, Canada) treatment was initiated using a total dose of 200 mg, given in twice-daily i.m. injections that decreased in dose over 4 days. A dose of 200 IU of eCG (Novormon®, Syntex, Buenos Aires, Argentina) i.m. was given at the time of sponge withdrawal. The AI was done by laparoscopy at 48 and 55 h after sponge withdrawal using fresh semen. The Day 0 protocol consisted of a previous 9-day synchronization treatment with a sponge containing 60 mg of MAP, followed by 150 μ of cloprostenol i.m. and 200 IU of eCG i.m. given on Day 7. A dose of 0.05 mg of GnRH (lecirelin; Gestran Plus®, Tecnopec) i.m. was given 16 h after sponge withdrawal. In a preliminary study, 38 ewes ovulated 42 ± 52 h after sponge withdrawal. Therefore, 48 h after sponge removal was considered as Day 0 and FSH treatment was initiated at that time, with a total dose of 200 mg of Folltropin®-V, given in 6 twice-daily decreasing doses. Two doses of cloprostenol (150 μg) were given i.m. concurrent with the fifth and sixth FSH treatments. Gonadotropin-releasing hormone (0.05 mg of lecirelin i.m.) was given 12 h after the last FSH treatment. Artificial insemination with fresh semen was done by laparoscopy 16 and 26 h after GnRH treatment. Five days after AI, embryos were recovered surgically. Results were evaluated by the parametric t-test. The number of corpora lutea and ova/embryos recovered did not differ (P > 0.05) between the traditional (9.8 ± 5.3; 4.5 ± 4.6) and Day 0 (10.0 ± 6.0; 3.5 ± 4.3) protocols. Similarly, no difference in the number of viable embryos was observed between treatments (1.6 ± 2.0 and 1.7 ± 2.4 for the traditional and Day 0 treatments, respectively). Within viable embryos, the traditional protocol (0.4 ± 1.0) resulted in ahigher (P < 0.05) number of morulae than that of the Day 0 protocol (0.1 ± 0.3). The ewes that had no superovulatory response did not differ (P > 0.05) between the traditional (11.11%) and Day 0 (5.56%) protocols. In summary, there was no difference in the parameters evaluated between both protocols. Financial support: FAPDF, CNPq, Tecnopec.

351 A COMPARISON OF 2 APPROACHES FOR THE USE OF GnRH TO SYNCHRONIZE FOLLICLE WAVE EMERGENCE FOR SUPEROVULATION

2015 ◽  
Vol 27 (1) ◽  
pp. 263 ◽  
Author(s):  
R. H. Hinshaw ◽  
M. L. Switzer ◽  
R. J. Mapletoft ◽  
G. A. Bó
Keyword(s):  
Mixed Models ◽  
Animal Health ◽  
Treatment Protocol ◽  
Prostaglandin F2α ◽  
Random Variable ◽  
Crossover Design ◽  
Dominant Follicle ◽  
Follicular Wave ◽  
Group 2 ◽  
Group 1

Although oestradiol has been used successfully to synchronize follicle wave emergence for superovulation, it cannot be used in many countries. Attention has turned to alternatives, including the use of GnRH to induce ovulation of a dominant follicle, which will be followed by emergence of a new follicular wave in 1 to 2 days. However, GnRH synchronizes follicular wave emergence only when it induces ovulation and administration of GnRH at random stages of the oestrous cycle results in ovulation in less than 60% of animals. The objective of the study was to compare superovulatory response and ova/embryo production following synchronization of follicle wave emergence for superovulation with GnRH administered 2 days after insertion of a progestin device, with a protocol in which GnRH is administered 7 days after administration of prostaglandin F2α and a progestin device. Beef donors of various breeds were placed at random into 1 of 2 groups and superstimulated by replicate so that one cow in each group had ova/embryos collected on the same day. Sixty-six superstimulations were performed in this study; 26 were performed in 13 donors that were superstimulated twice in a crossover design, and 40 donors were superstimulated once (i.e. 20 donors in each treatment group). Cows in group 1 received CIDR devices (Zoetis Animal Health, USA) on Day –2 and 100 μg of GnRH (Cystorelin, Merial USA) on Day 0; FSH treatments were initiated on Day 2 with 288 mg of Folltropin-V (Vetoquinol, Canada) given in twice-daily decreasing doses for 4 days. Prostaglandin F2α (PGF; 35 mg dinoprost, Lutalyse, Zoetis) was given with the last 2 injections of Folltropin-V and CIDR were removed with the last Folltropin-V administration (i.e. Day 6). Donors received a second GnRH at the onset of oestrus and were AI 8 and 20 h later. Donors that were still in standing oestrus at the second AI were AI again at 30 h. Ova/embryo collections were done on Day 14 and embryos were classified according to the IETS manual. Cows in group 2 received an injection of PGF and a CIDR on Day –7 and 100 μg of GnRH on Day 0; FSH treatments were initiated on Day 2 and the remainder of the treatment protocol was as in group 1. Data (total ova/embryos collected and transferable embryos) were analysed by ANOVA for mixed models, using treatment as a fixed variable and cow (i.d.) as a random variable. The group 1 cows produced a mean (± s.e.m.) of 18.6 ± 1.9 total ova/embryos of which 12.7 ± 1.5 were of transferable quality (7.2 ± 1.3 grade 1). Cows in group 2 produced a mean (± s.e.m.) of 19.5 ± 1.7 total ova/embryos, of which 14.8 ± 1.5 were of transferable quality (8.9 ± 1.2 grade 1). Although 2 more transferable embryos were obtained in group 2, differences were not significant (P > 0.3). At the same time as this experiment was done, 214 other cows were superstimulated in this practice, yielding an average of 7.9 transferable embryos per donor. Results suggest that both approaches are efficacious for the superstimulation of beef cows.Special thanks to Vetoquinol/Bioniche Animal Health, USA for support.

173 ESTRADIOL-17β CONCENTRATIONS IN BLOOD AND MILK DURING SUPEROVULATORY TREATMENT IN DAIRY COWS

2010 ◽  
Vol 22 (1) ◽  
pp. 245
Author(s):  
R. Dupras ◽  
J. Dupras ◽  
Y. Chorfi
Keyword(s):  
Los Angeles ◽  
Dairy Cows ◽  
Artificial Insemination ◽  
Animal Health ◽  
Follicular Wave ◽  
Milk Samples ◽  
Pfizer Animal Health ◽  
Estradiol 17Β

In cows, estradiol-17β is usually used to synchronize follicular wave emergence during superovulatory treatment. This approach, however, raises some concerns about the presence of estrogens in bovine products and their possible association with some human estrogen-sensitive cancers. The objective of this study was to determine estradiol-17β concentrations in blood and milk of dairy cows after i.m. injection of estradiol-17β and to compare these concentrations to those obtained during standard superovulation protocols. Six cows were used for this experiment. On Day 0, corresponding to Day 7 of their ensuing cycle, cows received 4.5 mg of estradiol-17β (Gentes et Bolduc, St-Hyacinthe, Québec, Canada) via i.m. injection and a progesterone-releasing vaginal insert (1.9 g of progesterone, CIDR, Pfizer Animal Health, Kirkland, Québec, Canada). Blood and milk samples were taken at 0, 24, 48, and 72 h after injection. From Day 4 evening to Day 8 evening, the cows received a total of 380 mg of NIH-FSH-P1 (Folltropin-V, Bioniche Animal Health, Belleville, Ontario, Canada) administered i.m. through 9 injections of decreasing dose (from 70 to 20 mg) at 12-h intervals. On Day 7, the cows received 2 injections consisting of 500 μg of cloprostenol (prostaglandin F2 α analogue, Estrumate, Shering-Plough, Pointe-Claire, Québec, Canada) given approximately 12 h apart and vaginal inserts were removed 12 h after the last injection. Artificial insemination was performed on Day 9 and 10 after treatment with 100 μg of GnRH i.m. (Cystorelin, Merial Canada Inc., Baie Urfe, Québec, Canada). A second batch of blood and milk samples was taken at Day 8, 9, 10, and 11. Measurement of estradiol-17β was performed with an IMMULITE chemiluminescent counter using an IMMULITE Estradiol Kit (Siemens Diagnostic Products Corporation, Los Angeles, CA, USA). Concentrations of estradiol-17β in blood (37.1 ± 15.6 pg mL-1 at 24 h, 19.1 ± 14.2 pg mL-1 at 48 h) and milk (38.4 ± 29.5 pg mL-1 at 24 h, 9.3 ± 4.9 pg mL-1 at 48 h) were significantly higher after i.m. injection of 4.5 mg of estradiol-17β. In comparison, superovulation heat (Day 9 to 11) increased estradiol-17β concentrations in blood (20 ± 13.6 pg mL-1 at 24 h, 32.5 ± 16.3 pg mL-1 at 48 h) but not in milk.

scholarly journals 15EFFECT OF DOSE OF ESTRADIOL VALERATE ON OVARIAN FOLLICULAR DYNAMICS IN CIDR-TREATED BEEF COWS

2004 ◽  
Vol 16 (2) ◽  
pp. 130 ◽  
Author(s):  
R.J. Mapletoft ◽  
M.G. Colazo ◽  
J.A. Small ◽  
D.R. Ward ◽  
J.P. Kastelic
Keyword(s):  
Ovarian Follicle ◽  
Animal Health ◽  
Beef Cows ◽  
Estradiol Valerate ◽  
Control Group ◽  
Dominant Follicle ◽  
Follicular Wave ◽  
Follicle Diameter ◽  
Growth Profiles ◽  
Follicular Dynamics

The objective was to investigate the effect of dose of estradiol valerate (EV) on ovarian follicular growth profiles, intervals to follicular wave emergence and, following CIDR removal, estrus and ovulation in beef cows. On Day 0, 43 non-lactating, crossbred beef cows, 3 to 9 yr of age and at random stages of the estrous cycle, received a CIDR (Bioniche Animal Health; Belleville, Ontario, Canada) and were randomly allocated to one of four groups to receive no further treatment (Control; n=10), or an injection of 1mg (n=11), 2mg (n=10), or 5mg (n=12) i.m. of EV (Sigma Chemical Co, St. Louis, MO, USA) in 2mL canola oil. On Day 7, CIDR were removed and cows received 500μg i.m. of cloprostenol (Estrumate, Schering Plough Animal Health, Pointe-Claire, Quebec, Canada). Ovaries were examined by transrectal ultrasonography once daily until 48h after CIDR removal to detect ovarian follicle growth profiles, and twice daily thereafter to detect ovulation. Data were analyzed by ANOVA (LSD and Bartlett’s tests) and chi-square procedures. One cow (5mg EV group) lost the CIDR and was removed from all analyses. There was an effect of day (P&lt;0.0001) on CL diameter, but the effects of treatment (P=0.3), and the treatment-by-day interaction (P=0.1), were not significant. Follicular wave emergence occurred within 7d in 7/10 (70%) Control cows and 31/32 (97%; P&lt;0.04) EV-treated cows (one cow in late diestrus at the time of treatment did not respond to 1mg EV). Mean (±SD) interval from treatment to wave emergence was longer (P&lt;0.03) in cows treated with 5mg EV (4.8±1.2d) than in those treated with 1mg (3.2±0.9 days) or 2mg EV (3.4±0.8 days), while Control cows were intermediate (3.8±2.0 days). Although follicular wave emergence tended (P&lt;0.09) to be more synchronous in cows receiving EV, intervals from CIDR removal to estrus (P=0.7) and ovulation (P=0.8) did not differ among groups. Diameter of the dominant follicle was smaller (P&lt;0.04) at CIDR removal and tended to be smaller (P&lt;0.08) just prior to ovulation in the 5mg EV group (8.5±2.2 and 13.2±0.6mm, respectively) than in the Control (11.8±4.6 and 15.5±2.9mm, respectively) or 1mg EV (11.7±2.5 and 15.1±2.2mm, respectively) groups, with the 2mg EV group (10.7±1.5 and 14.3±1.7mm, respectively) intermediate. Diameter of the dominant follicle at CIDR removal was less variable (P&lt;0.01) in the 2 and 5mg EV groups than in the Control group and intermediate in the 1mg EV group. In summary, dose of EV affected follicular dynamics, interval to and synchrony of follicular wave emergence, and dominant follicle diameter at CIDR removal and just prior to ovulation in CIDR-treated cows. However, interval from CIDR removal to estrus and ovulation was not affected by treatment. Results suggest that a dose of 2mg EV may be most efficacious in synchronizing follicular wave emergence in CIDR-treated cows.

Identification of novel genes associated with dominant follicle development in cattle

2007 ◽  
Vol 19 (8) ◽  
pp. 967 ◽  
Author(s):  
Anna E. Zielak ◽  
Niamh Forde ◽  
Stephan D. E. Park ◽  
Fiona Doohan ◽  
Paul M. Coussens ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Follicular Development ◽  
Intracellular Signalling ◽  
Follicle Development ◽  
The Novel ◽  
Dominant Follicle ◽  
Novel Genes ◽  
Follicular Wave ◽  
New Genes ◽  
Follicle Selection

Follicle development is regulated by the interaction of endocrine and intrafollicular factors, as well as by numerous intracellular pathways, which involves the transcription of new genes, although not all are known. The aim of the present study was to determine the expression of a set of unknown genes identified by bovine cDNA microarray analysis in theca and granulosa cells of dominant and subordinate follicles, collected at a single stage of the first follicular wave using quantitative real-time polymerase chain reaction. Differences were further examined at three stages of the follicular wave (emergence, selection and dominance) and bioinformatics tools were used to identify these originally unknown sequences. The suggested name function and proposed role for the novel genes identified are as follows: MRPL41 and VDAC2, involved in apoptosis (dominant follicle development); TBC1D1 stimulates cell differentiation (growth associated with dominant follicle selection and development); STX7, promotes phagocytosis of cells (subordinate follicle regression); and SPC22 and EHD3, intracellular signalling (subordinate follicle regression). In conclusion, we have identified six novel genes that have not been described previously in ovarian follicles that are dynamically regulated during dominant follicle development and presumably help mediate intracellular signalling, cell differentiation, apoptosis and phagocytosis, events critical to follicular development.

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