227 Is the antral follicle count on a random day of the oestrous cycle correlated with superovulatory responses in Santa Inês ewes?

2020 ◽  
Vol 32 (2) ◽  
pp. 241
Author(s):  
M. Pupin ◽  
G. Vergani ◽  
M. Lima ◽  
K. Silva ◽  
A. Monteiro ◽  
...  

Antral follicle count (AFC) performed after an oestrus synchronization protocol has been studied as a tool to select ewes with high potential for invivo embryo production (Pinto et al. 2018 Theriogenology 113, 146-152). However, it would be interesting to know whether AFC assessed on a random day of the oestrous cycle correlates with the superovulatory response. The present study was conducted to evaluate the correlation between AFC at the beginning of progesterone (P4)-based oestrus synchronization protocol used as basis of superovulatory treatment and the number of corpora lutea (CL) 12h before recovery of embryos in Santa Inês ewes. The study was conducted during September and October in northeast Brazil (03°40′26″S and 40°14′20″W) using 8 adult Santa Inês ewes. On a random day of oestrous cycle (Day 0) all ewes received an intravaginal device (CIDR) of progesterone (0.3g, Eazi-breed, Zoetis), which remained for 9 days. On Day 7, the pFSH (133mg, Folltropin V, Vetoquinol) treatment began, with 6 decreasing doses (25, 25, 15, 15, 10, and 10%) injected IM at 12-h intervals. On Day 9, 2 equal doses of D-cloprostenol were injected at a 12-h interval (37.5µg, Prolise, Agener União). All ewes showed oestrus and were mated by fertile rams. Flunixin meglumine (24.9 mg; Banamine, MSD Animal Health) was administered IM on Days 12, 13, and 15. On Day 16, non-surgical embryo recovery (NSER) was performed after cervical dilation using D-cloprostenol and oestradiol benzoate at 16h and oxytocin 20min before. Transrectal B-mode ultrasound evaluations (Z5 Vet, Mindray), frequency 7.5MHz, were performed on Day 0 and 7 and 12h before NSER to evaluate the ovarian population present. Pearson correlation analysis (P<0.05) was performed using Bioestat 5.3 software. The number of AFC per ewe at the beginning of the protocol and on Day 7 were 9.9±2.7 and 11±3.2, respectively. The numbers of CL, recovered embryos, and viable embryos were 14.0±3.5, 8.2±10.9, and 6.0±11.0, respectively. There was no correlation of AFC on a random day of oestrous cycle with the number of AFC on Day 7 (P=0.42), number of corpora lutea (P=0.44), number of recovered embryos (P=0.18), or number of viable embryos (P=0.11) in superovulated ewes. In conclusion, we did not find significant correlations between AFC on a random day of oestrous cycle and the superovulatory/embryos response in Santa Inês ewes. Financial support for this study was provided by Embrapa (02.13.06.026.00.02 and 02.13.06.026.00.04) and FAPEMIG (PPM 00201-17).

2020 ◽  
Vol 32 (2) ◽  
pp. 240
Author(s):  
G. B. Vergani ◽  
M. S. D. Lima ◽  
K. M. Silva ◽  
A. W. U. Monteiro ◽  
A. F. Ramos ◽  
...  

The objective of this study was to evaluate the correlation between the number of corpora lutea (CL), as determined by B-mode ultrasonography, and the total number of structures recovery by non-surgical embryo recovery (NSER) from superovulated ewes. Somali (n=18), Santa Inês (n=18), and Morada Nova (n=16) ewes received an intravaginal device with progesterone (0.33g, controlled internal drug release device, CIDR, Zoetis), which was maintained for 9 days. The superovulatory protocol started 60h before device removal, with 6 decreasing doses (25, 25, 15, 15, 10, and 10%) of p-FSH (IM 133mg, Folltropin V, Vetoquinol) injected every 12h. D-Cloprostenol (IM 37.5μg, Prolise, Agener Union) was injected 12h before and at the moment of device removal. Ewes in oestrus were mated by fertile male rams three times after the onset of oestrus with a 12-h interval. Flunixin meglumine (24.9 mg; Banamine, MSD Animal Health) was injected IM on Days 12, 13, and 15. One day before NSER, B-mode ultrasound evaluations were performed using portable equipment (Z5 Vet, Mindray) with a stiffened multifrequency linear probe to evaluate the number of structures present in the ovaries. Embryo recovery was performed 7 days after progesterone CIDR removal (Day 16). The number of CL and the number of recovered structures were determined and their association evaluated using the Pearson correlation test (P<0.05). Only 17 Somali, 16 Santa Inês, and 15 Morada Nova ewes were submitted to NSER; the other 4 ewes could not be flushed because of low cervical dilation or cervical puncture. After B-mode ultrasound evaluation, 168, 217, and 131 CL were observed, with an average of 9.9 (range: 1 to 12), 13.5 (range: 2 to 47), and 8.7 (range: 3 to 18) CL per donor for Somali, Santa Inês, and Morada Nova ewes, respectively. The recovery rates (i.e. structures recovered by the number of CL counted) were 60.1% (101/168), 96.3% (209/217), and 103.5% (135/131) for the 3 breeds, respectively. There was a positive correlation (r=0.69; P<0.01) between the number of recovered structures and number of CL. Those findings confirm results from other studies, in which the recovery rate varied from 35 to 91%. In some cases, recovery rate can be overestimated because of the difficulty in quantifying CL. In conclusion, B-mode ultrasonography can be used to estimate superovulatory response in ewes and thus as a criterion to decide whether a donor will undergo embryo flushing. Financial support for this study was provided by Embrapa (02.13.06.026.00.04) and Fapemig (CVZ-PPM 00201-17).


2014 ◽  
Vol 26 (1) ◽  
pp. 168
Author(s):  
H. W. Vivanco-Mackie ◽  
M. D. Ponce Salazar ◽  
M. M. Gonzales ◽  
M. A. Tapia

Alpacas are induced ovulators, responding to copulation and (or) exogenous application of ovulation-inducing hormones. The objective of this study was to determine the efficiency of the injection of a gonadotropin-releasing hormone (GnRH) agonist versus LH in the induction of ovulation and the presence and size of non-ovulated follicles at the time of embryo collection and its relationship to the yield of transferable embryos in superovulated alpacas. Twenty-one adult (3 to 7 years old) female alpacas under extensive grazing at 4300 m elevation in the Peruvian Andes that had been synchronized and treated for superovulation were induced to ovulate 6 days after the application of the superovulatory hormone (1000 IU of eCG, Folligon®, Intervet International BV, Boxmeer, the Netherlands) by mating with fertile males and injection immediately after copulation of either an IM dose of 0.0084 mg of buserelin acetate (Buserelina Zoovet®, Laboratorio Zoovet, Santa Fe, Argentina) to 10 alpacas (T1) or an IM dose of 5-mg Armour standard of LH (Lutropin®, Bioniche Animal Health, Belleville, ON, Canada) to 11 alpacas (T2). All alpacas had a second mating 12 h after the first mating and were subjected to ovarian inspection by ultrasonography and previous embryo collection by nonsurgical transcervical embryo flushing 6.5 days after the first mating. On average, the embryo recovery rate for T1 was 34.6% and there were 7.8 ± 3.99 corpora lutea (CL), 2.7 ± 4.08 collected embryos, and 3.6 ± 2.95 total, 0.5 ± 0.85 small (<6 mm), 1.8 ± 1.99 medium (≥6 but ≤14 mm), and 1.3 ± 2.11 large (≥15 mm) non-ovulated follicles. For T2, the embryo recovery rate was 59.4% and there were 6.73 ± 1.49 CL, 4.0 ± 2.57 collected embryos, and 0.64 ± 0.81 total, 0.0 ± 0.0 small, 0.36 ± 0.67 medium, and 0.27 ± 0.47 large non-ovulated follicles. The differences between treatments were nonsignificant (P > 0.05) for all the parameters; however, there was a clear tendency for a better recovery rate, more embryos collected, and lower number of non-ovulated follicles in T2. The Pearson correlation coefficient between the presence of large follicles in the ovaries at the time of embryo collection and the total number of embryos collected was negative (r = –0.26) and highly significant (P ≤ 0.001). The use of LH for ovulation induction of superovulated alpacas seems to be more advisable than the use of GnRH agonist; further comparisons with larger number of observations per treatment are recommended. This study was financed by the Peruvian Fund for Innovation, Science and Technology (FINCYT).


2020 ◽  
Vol 32 (2) ◽  
pp. 241
Author(s):  
M. S. D. Lima ◽  
G. B. Vergani ◽  
K. M. Silva ◽  
A. W. U. Monteiro ◽  
L. M. C. Pereira ◽  
...  

The high variability of responses to multiple ovulation and embryo transfer (MOET) programs is related to several factors, including the ovarian population present at the beginning of hormonal protocols. Thus, our objective was to evaluate the effect of the presence or absence of corpus luteum (CL) in females presenting small antral follicles (SF) at the beginning of a progesterone (P4)-based oestrus synchronization protocol on superovulatory response and embryo yields. The study was conducted during September and October in northeast Brazil (03°40′26″S and 40°14′20″W) using 15 adult Santa Inês ewes, in which the ovarian population present were SF (≤3.75mm, n=5) or SF plus CL (SF+CL, n=10) at the beginning of P4-based oestrus synchronization protocol. The females received a new or reused intravaginal device of progesterone (CIDR Eazi-breed, Zoetis) on Day 0, which remained for 9 days. On Day 7, the pFSH (133mg, Folltropin V, Vetoquinol) treatment was begun, with 6 decreasing doses (25, 25, 15, 15, 10, and 10%) injected IM at 12-h intervals. On Day 9, two equal doses of D-cloprostenol were injected at a 12-h interval (37.5μg, Prolise, Agener União). Flunixin meglumine (24.9 mg; Banamine, MSD Animal Health) was administered IM on Days 13 to 15. All ewes showed oestrus and were mated with fertile rams. On Day 16 non-surgical embryo recovery (NSER) was performed after cervical dilation using D-cloprostenol and oestradiol benzoate at 16h and ocytocin at 20min before. Transrectal B-mode ultrasound evaluations (Z5 Vet, Mindray) were performed on Day 0 and just before NSER to evaluate the ovarian population present. Data are showed in mean±s.d. and compared by t-test for independent samples (P&lt;0.05). The number of CL present on NSER day (21.5±4.4 and 4.0±8.5) and the number of viable embryos (11.1±14.9 and 4.0±8.5) differed (P&lt;0.05) between SF+CL ewes and SF ewes, respectively. However, the number of luteinizing unovulated follicles present on NSER day (4.5±2.5 and 12.4±7.8) and the number of recovered structures (i.e. embryos plus unfertilized eggs; 14.2±15.6 and 4.2±8.2) did not differ (P&gt;0.05) between SF+CL ewes and SF ewes, respectively. In conclusion, the presence of a CL at the beginning of the oestrous synchronization protocol used for superovulation treatment affects responses to the MOET program. Financial support for this study was provided by Embrapa (02.13.06.026.00.02 and 02.13.06.026.00.04) and FAPEMIG (PPM 00201-17).


2014 ◽  
Vol 26 (1) ◽  
pp. 184
Author(s):  
C. C. Chase ◽  
E. C. Wright ◽  
A. K. McNeel ◽  
R. A. Cushman ◽  
G. A. Perry ◽  
...  

Pubertal heifers can be classified between those with high (n = 25) or low (n = 15) antral follicle counts (AFC). The objective of this study was to determine oocyte development and maturation (e.g. fertility) in an IVF system for high- and low-AFC heifers. From a pool of 120 heifers, 10 high- and 10 low-AFC heifers were determined by transrectal ultrasonography; all heifers with evidence of oestrous cyclicity (i.e. pubertal) were synchronized with two 5-mL injections of prostaglandin F2α 11 days apart. Heifers were euthanized over 4 days on Days 15 to 16 of the synchronized oestrous cycle. A total of 15 heifers (n = 7 high and n = 8 low AFC) were at the appropriate stage of the oestrous cycle. Ovaries were collected and transported to the laboratory. Follicles less than 8 mm in diameter were aspirated. The IVF procedures and media were as previously described (Miles et al. 2004. Biol. Reprod. 71, 1919–1926). Cumulus-oocyte complexes (COC) were identified and washed in oocyte collection medium and then in maturation medium and were cultured (5% CO2; 38.5°C) for 24 h. Following maturation, COC were transferred and washed in fertilization medium. Thawed frozen semen from a crossbred bull was subjected to the swim-up procedure. Motile spermatozoa were collected and added to COC to yield a final concentration of spermatozoa per milliliter of fertilization medium. About 24 h later, presumptive zygotes were washed in development medium, placed in microdrops of development medium, and cultured for 8 days. On Days 3 and 8 after fertilization, cleavage and blastocyst development, respectively, were assessed. Data were analysed using the Proc Mixed procedure of SAS (SAS Institute Inc., Cary, NC, USA) and the model included the effects of day of collection (n = 4), group (n = 7 high- or n = 8 low-AFC heifers), and the interaction. The interaction did not differ (P = 0.10). Day of collection influenced (P < 0.05) the number of COC and the number of oocytes cleaved. High- compared to low-AFC heifers had the greater (P < 0.05) numbers of COC (42.7 ± 4.66 v. 22.1 ± 4.59), oocytes that cleaved (28.1 ± 3.60 v. 15.9 ± 3.55), and developed to blastocysts (13.2 ± 1.71 v. 6.2 ± 1.69). However, there was no difference (P > 0.10) in the percentage of COC that cleaved (65.3 ± 5.58 v. 66.2 ± 5.50%, high v. low, respectively) or that developed to blastocysts (46.7 ± 6.75 v. 42.2 ± 6.65%). In conclusion, AFC did not appear to affect oocyte maturation and development through the blastocyst stage.


2015 ◽  
Vol 27 (1) ◽  
pp. 264
Author(s):  
B. Lahoz ◽  
J. L. Alabart ◽  
M. J. Cocero ◽  
D. Monniaux ◽  
S. Fabre ◽  
...  

The performance of MOET (multiple-ovulation embryo transfer) programs in sheep is limited, mainly due to variable ovarian responses to FSH superovulation treatments. In several mammalian species, anti-Müllerian hormone (AMH) has been demonstrated to be a good predictor of the ovarian follicle population able to respond to gonadotropins. Therefore, we aimed to evaluate its usefulness in ovine MOET programs. With this goal, two MOET trials involving 24 adult ewes in total were performed. Each ewe received a fluorogestone acetate sponge (Sincropart 30 mg, CEVA Animal Health SA, Barcelona, Spain) which was replaced by a new one after 6 days (T–4). Four days later (T0), the first FSH injection (Folltropin-V, Minitub Ibérica SL, Tarragona, Spain) of a superovulation treatment consisting in 280 IU of FSH administered in 8 decreasing doses was applied. Blood samples were taken at T–4 and T0 using lithium heparin tubes for AMH measurement. Ewes were inseminated 51 h after sponge removal. Eight days after sponge removal, ovulation rate was recorded and embryo recovery was carried out under general anaesthesia. After morphological evaluation, 2 embryos were transferred to each recipient previously synchronized. The plasma concentrations of AMH were determined using the AMH equine ELISA kit (AnshLab, Webster, TX, USA). The sensibility of the assay was 27.8 pg mL–1, and the intra-assay coefficient of variation was 4.8%. Relationships between the AMH concentration of each animal and the number of corpora lutea (CL), embryo recovered and lambs born per donor ewe were tested using the Pearson correlation coefficient. Normality of the variables was assessed by Kolmogorov–Smirnov test. The plasma AMH concentrations at T–4 were highly correlated with those at T0 (r = 0.95; P < 0.01), so both sampling times could be used indistinctly. The plasma AMH concentration at T0 was highly variable between animals, ranging from 0 to 309.1 pg mL–1 (mean ± s.e.m.: 98.4 ± 18.4 pg mL–1). Similarly, the number of CL ranged from 2 to 29 (12.2 ± 1.5), recovered embryos from 0 to 17 (7.6 ± 1.2), and lambs born per donor and session from 0 to 13 (4.5 ± 0.9). The AMH concentration at the beginning of the FSH treatment (T0) was highly correlated with the total number of CL (r = 0.70; P < 0.01), but significance was not attained for AMH with the other variables. The number of CL was also correlated with the number of recovered embryos (r = 0.69; P < 0.01) and lambs born (r = 0.58; P < 0.01). In conclusion, AMH concentrations measured in blood plasma before the FSH treatment could be used to predict the number of CL per donor ewe, and so to improve the efficiency of MOET programs. Further studies are necessary to assess the individual repeatability of a given ewe from session to session as well as the relationship of AMH with other embryo-related variables.


2012 ◽  
Vol 24 (1) ◽  
pp. 228
Author(s):  
M. E. F. Oliveira ◽  
C. C. D'Amato ◽  
L. G. Oliveira ◽  
S. D. Bicudo ◽  
J. F. Fonseca ◽  
...  

This study was designed to investigate if the superovulatory response and embryo yield in Santa Ines ewes are influenced by the time that FSH treatments are inititiated: near the emergence of the first or last follicular wave of a progesterone-based (P4) protocol. Days of emergence of the follicular waves was defined in a previous study that evaluated follicular dynamics in oestrus synchronization treatments (Oliveira et al. 2011 Acta Sci. Vet. 40). Twenty Santa Ines cyclic ewes were submitted to 2 superovulatory protocols according to the time that FSH treatments were initiated (G-first wave, n = 10 and G-last wave, n = 10). Thus, the FSH treatment started on Day 4 and 10 of protocol for G-first and G-last, respectively (Day 0 = onset of protocol). Ewes were treated with a P4 device (CIDR®; Pfizer-New Zealand) for 6 and 12 days for G-first and G-last, respectively. Additionally, in G-last, the CIDR was replaced by a new one on Day 7. All ewes received 2 injections of 37.5 μg of D-cloprostenol (Prolise®, Arsa-Argentina) on Day 0 and at CIDR removal. The superovulatory regimen consisted of 8 IM injections of pFSH (Folltropin®; Bioniche Animal Health, Belleville, Ontario, Canada) administrated twice daily (40, 40, 30, 30, 20, 20, 10 and 10 mg of porcine FSH). A single IM dose of 200 IU of eCG (Novormon®, Syntex, Buenos Aires, Argentina) was given concurrently with CIDR removal. Ewes were mated by a fertile ram. Embryo collections were accomplished 7 days after CIDR removal. The superovulatory response was classified in scores: (0) 4 or fewer corpora lutea (CL); (1) between 5 and 10 CL and (2) 11 or more CL. Means (± SD) were compared using Kruskal-Wallis test and percentages using Chi-square (P < 0.05). Most donors (70%, 7/10) from G-last had a superovulatory response classified as score 2 and the remainder (30%, 3/10) as score 1, whereas half of ewes from G-first were classified as score 2 and half as score 1 (P > 0.05).There was no effect between treatments (P > 0.05) for ovulation rate (G-first: 90.7 ± 10.2% vs G-last: 93.0 ± 7.2%), number of ovulations (G-first: 13.1 ± 7.3 vs G-last: 14.0 ± 5.8), or number of luteinized unovulated follicles (G-first: 1.4 ± 1.3 vs G-last: 0.9 ± 1.0). Furthermore, there was no effect between G-first and G-last (P > 0.05) in the rate of ova/embryos recovered (55.1 ± 27.1% vs 67.0 ± 19.4%), mean number of ova/embryos recovered (7.0 ± 5.5 vs 9.1 ± 3.8), number of viable embryos (3.9 ± 6.1 vs 5.7 ± 4.4), or viability rate (49.1 ± 43.7 vs 58.5 ± 34.6). In conclusion, superovulatory response and embryo yield did not differ between FSH treatments initiated during the first or last follicular wave of a progesterone-based treatment in Santa Ines ewes. Financial support of FAPESP is acknowledged.


2018 ◽  
Vol 30 (1) ◽  
pp. 143
Author(s):  
F. Morotti ◽  
R. Moretti ◽  
G. M. Gomes dos Santos ◽  
K. C. Silva-Santos ◽  
M. M. Seneda

Two experiments in Nelore cows subjected to conventional protocol for timed AI (TAI) were designed to compare the influence of antral follicle count (AFC; 1) on the ovarian follicular dynamics and (2) conception rates. First, multiparous cows with high (G-high, ≥45 follicles; n = 43) and low AFC (G-low, ≤15 follicles; n = 32) were selected to receive a conventional oestradiol/progesterone-based TAI protocol for monitoring ovarian follicular dynamics. Second, AFC from 962 multiparous suckling cows (40 ± 15 days postpartum) subjected to a conventional protocol for TAI were classified as G-high (≥45 follicles; n = 194), G-intermediate (≥20 and ≤40 follicles, n = 397), and G-low AFC (≤ 15 follicles; n = 243). Pregnancy status was evaluated 30 to 35 days later. Data were analysed using ANOVA followed by the Tukey test and model of logistic regression (P ≤ 0.05). In the first study, the AFC were greater (P ≤ 0.05) in G-high than in G-low, but remained stable in both groups during the evaluations. The ovarian diameter, perimeter, and area were greater (P ≤ 0.05) in G-high than in G-low (28.3 ± 3.9 v. 20.5 ± 3.2 mm, 100.9 ± 13.2 v. 73.8 ± 13.9 mm, and 67.5 ± 16.4 v. 37.7 ± 11.7 mm2; respectively). Follicular growth rate, time of ovulation, corpus luteum diameter, and progesterone concentration were similar (P > 0.05) for cows with low or high AFC. Dominant follicles showed greater (P ≤ 0.05) diameter in G-low than G-high at D4 (7.3 ± 2.2 v. 6.2 ± 1.4 mm; P = 0.069, tendency), D8 (11.2 ± 1.8v. 9.5 ± 1.8 mm), D9 (12.3 ± 1.7 v. 10.6 ± 1.7 mm), and D10 (13.4 ± 1.3 v. 12.2 ± 1.8 mm), and the estimated diameter of the ovulatory follicle tended (P = 0.08) to be higher in G-low than in G-high (14.4 ± 1.5 v. 13.4 ± 2.1 mm). In the second study, AFC of G-low cows showed higher (P ≤ 0.05) conception rate (61.7%) than those of G-intermediate (52.9%) and G-high (49.5%) cows. In Nelore cows subjected to ovulation synchronization protocol, cows with high AFC showed higher ovarian measurements, but those with low AFC had large follicular diameters. Additionally, the cows with low AFC showed higher conception rate than groups with intermediate and high counts.


2019 ◽  
Vol 31 (1) ◽  
pp. 185
Author(s):  
K. Sakaguchi ◽  
Y. Yanagawa ◽  
K. Yoshioka ◽  
T. Suda ◽  
K. Kawano ◽  
...  

The antral follicle count (AFC) in mammalian ovaries positively correlates with female fertility. We have reported previously that cumulus-oocyte complexes derived from high-AFC ovaries produce more oestradiol-17β (E2) and have higher developmental competence than those from low-AFC ovaries in in vitro growth (Sakaguchi et al. WCRB2017, Okinawa, Japan; 1-15). We also indicated that follicular growth was different between high- and low-AFC cows, and that follicular deviation occurred earlier in high-AFC cows (Nagai et al. 2015 Anim. Reprod. Sci. 163, 172-178). To clarify the causes of the higher E2 production and earlier follicular deviation in high-AFC cows, we investigated circulating steroid hormones and FSH during the oestrous cycle, as well as steroidogenesis in follicles at different phases of the oestrous cycle. Four high-AFC cows (&gt;40 follicles) and 3 low-AFC cows (&lt;20 follicles) based on the peak AFC were used. We ablated their follicles 8 days after oestrus and administered prostaglandin F2α on Day 12. After 40h of prostaglandin F2α injection, follicular fluid of a dominant follicle (preovulatory phase) was collected and subordinate follicles were ablated. Gonadotropin-releasing hormone was then injected to induce LH surge. Seven days after gonadotropin-releasing hormone, follicular fluids were collected from dominant follicles (luteal phase) and all follicles were ablated. Four days later, follicular fluids were again collected from the largest follicles (selection phase). Steroid hormones in follicular fluids were measured by enzyme immunoassay. Throughout the study, we daily examined ovaries by ultrasonography and collected blood for hormone measurements. We analysed data using two-way ANOVA followed by Tukey-Kramer or Student’s t test. The number of small follicles (&lt;4mm) was greater in high-AFC than low-AFC groups (low v. high=7.6v. 46.9; P&lt;0.05), whereas that of large follicles (&gt;8mm) was similar between groups (0.8v. 0.8) at any time. Although the number of medium-sized follicles (4-8mm) was not affected in the low-AFC group (4.2-6.7) after follicle ablation, the number increased from 1 to 4 days (10.5 to 17.8) then decreased 6 days after follicle ablation (11.5) in the high-AFC group, which means that degradation of follicles occurs at selection phase in high-AFC cows. Peripheral FSH concentration was higher (low v. high: 4.7v. 2.1 ng/mL), but E2 concentration was lower in the low-AFC (2.4 pg/mL) than high-AFC group (3.3 pg/mL) during the selection phase (P&lt;0.05). Although follicular diameter was similar in both groups at any phase, E2 (low v. high=333.8v. 1127.4 ng/mL; P&lt;0.05) and testosterone (low v. high=16.7v. 35.0 ng/mL; P=0.07), but not progesterone, concentrations were higher in the high-AFC than low-AFC group in the preovulatory phase. These findings suggest that a lower response to FSH causes low E2 production in the low-AFC group, resulting in high FSH concentration and a consistent development of medium-sized follicles. Conversely, higher E2 concentration suppresses FSH secretion, resulting in obvious degradation of follicles in the high-AFC group at the selection phase.


2004 ◽  
Vol 52 (4) ◽  
pp. 489-499 ◽  
Author(s):  
B. Bényei ◽  
Margit Kulcsár ◽  
A. Gáspárdy ◽  
Anna Pécsi

Changes of progesterone (P4) profiles and oestrous cycle were investigated up to 70 days in 20 superovulated Holstein-Friesian cows in a dry tropical environment (Brazil). Superovulated cows showed no significant differences in relation to P4 level at the time of embryo recovery (39.0 ± 27.1 nmol/L, P = 0.536), first and second (12.0 ± 6.0 and 10.7 ± 2.2 nmol/L, P = 0.543) cycle. There was a close correlation between serum P4 concentration and the number of corpora lutea (CL; 13.3 ± 9.5) at the recovery (P < 0.0001). After the embryo collection, cows returned to cycle in different ways: (i) group of donors returning to cycle after 2.2 ± 0.8 days, (ii) group with a delay of 11.0 ± 1.9 days; and (iii) animals having a long (28.8 ± 2.2 days) acyclic period, which is significant (P < 0.001). The remaining animals (30%) showed cystic ovarian malformations. P4 level at the time of embryo recovery does not influence the oestrous cycle changes. The results suggest that Holstein-Friesian donor cows may suffer from cystic ovarian degeneration and may have a long acyclic period after superovulatory treatment in a tropical climate.


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.


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