7 Ovarian Follicular Dynamics and Conception Rate in Bos indicus Cows with Different Antral Follicle Counts Subjected to Timed Artificial Insemination

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.

2018 ◽  
Vol 188 ◽  
pp. 170-177 ◽  
Author(s):  
Fábio Morotti ◽  
Rogério Moretti ◽  
Gustavo Martins Gomes dos Santos ◽  
Katia Cristina Silva-Santos ◽  
Pedro Henrique Ramos Cerqueira ◽  
...  

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marina Amaro de Lima ◽  
Fábio Morotti ◽  
Bernardo Marcozzi Bayeux ◽  
Rômulo Germano de Rezende ◽  
Ramon Cesar Botigelli ◽  
...  

Abstract We evaluated the effect of the antral follicle count (AFC) on ovarian follicular dynamics, pregnancy rates, progesterone concentrations, and transcriptional patterns of genes in Nelore cattle (Bos taurus indicus) after a timed artificial insemination (TAI) programme. Cows were separated based on the AFC, and those with a high AFC showed a larger (P < 0.0001) ovarian diameter and area than those with a very low AFC. Females with a very low AFC exhibited a larger (P < 0.01) diameter of the dominant follicle at TAI (13.6 ± 0.3 vs. 12.2 ± 0.4 mm) and a tendency (P = 0.06) to have different serum progesterone concentrations (2.9 ± 0.3 vs. 2.1 ± 0.3 ng/mL; on day 18, considering day 0 as the beginning of the synchronization protocol) than those with a high AFC. The pregnancy rate was higher (P ≤ 0.05) in animals with a very low (57.9%) and low (53.1%) AFC than in those with a high AFC (45.2%). The expression of genes related to intercellular communication, meiotic control, epigenetic modulation, cell division, follicular growth, cell maintenance, steroidogenesis and cellular stress response was assessed on day 5. In females with a low AFC, 8 and 21 genes in oocytes and cumulus cells, respectively, were upregulated (P < 0.05), while 3 and 6 genes in oocytes and cumulus cells, respectively, were downregulated. The results described here will help elucidate the differences in ovarian physiology and the reproductive success of Bos indicus females with a low or high AFC.


2021 ◽  
pp. 104586
Author(s):  
Camila Oliveira Rosa ◽  
Camila Bortoliero Costa ◽  
Camila Bruna de Lima ◽  
Camila Bizarro da Silva ◽  
Amanda Fonseca Zangirolamo ◽  
...  

2021 ◽  
Vol 33 (2) ◽  
pp. 168
Author(s):  
L. F. Feres ◽  
L. G. B. Siqueira ◽  
L F. M. Pfeifer ◽  
L. L. Santos ◽  
J. H. M. Viana

Anti-Müllerian hormone (AMH) has a well-known association with antral follicle count (AFC) and the number of oocytes recovered by OPU in cattle. However, to be used as a criterion to select candidate donors for ART, AMH reference values must be established for each breed. The aim of this study was to estimate AMH cutoff values for selecting oocyte donors in Gir (Bos indicus) cattle. A blood sample was collected at a random day of oestrous cycle from Gir heifers (n=120) at 23.3±0.5 months of age, and the plasma was stored for further AMH analysis by ELISA, using a commercial kit (AL114, AnshLabs) in a private laboratory (LEAC, Sao Paulo, Brazil). Data from 506 ovum pickup-invitro embryo production (OPU-IVEP) sessions (4.2±0.2 per donor) performed in these heifers from 2017 to 2019, starting 120 days after blood sampling, were then analysed. Donors were ranked in quartiles according to the number of total oocytes recovered, viable oocytes recovered, and embryos produced. Those classified in the first quartile for each endpoint were considered poor responders. The AMH values were then analysed using the receiver operating characteristic (ROC) curve, and cutoff values for each endpoint were estimated based on best values for sensitivity and specificity. A second analysis was performed to check which cutoff value would result in a significant increase in average for each endpoint. The OPU-IVEP data were ranked according to corresponding AMH values (smaller to greater), and the average of the selected group of donors was compared with the original group by ANOVA, using the PROC GLM of SAS (SAS Institute Inc.), after successive exclusion of donors with lower AMH concentrations. Results are shown as mean±s.e.m. On average, heifers presented AMH concentrations of 932.9±48.4pgmL−1 (ranging from 112.7 to 2044.8pgmL−1) and produced 32.3±1.5 total oocytes, 25.9±1.4 viable oocytes, and 5.3±0.4 embryos per OPU-IVEP session. The heifers ranked in the third and last quartiles yielded more total oocytes, viable oocytes, and blastocysts than those ranked in the first quartile (P&lt;0.05). Based on the total number of oocytes recovered (59.2±3.1), heifers of the last quartile had an estimated AFC &gt;60. The area under the ROC curve (AUC) for total oocytes, viable oocytes, and embryos produced were 0.77 (P&lt;0.0001), 0.75 (P&lt;0.0001), and 0.72 (P=0.0003), and the estimated cutoffs for AMH concentration were 761.4, 622.5, and 681.5pgmL−1, respectively. After successive exclusions of donors with lower AMH values, averages were greater (P&lt;0.05) at a cutoff value of 632.4pgmL−1 for total oocytes (36.9±1.6 vs. 32.3±1.5; +15.3%), 672.3pgmL−1 for viable oocytes (30.3±1.4 vs. 25.9±1.4; +19.4%), and 776.8pgmL−1 for embryos produced (6.6±0.3 vs. 5.3±0.4; +23.4%). However, the use of these cutoff values to increase the averages would result in the exclusion of 32.8, 37.9, and 50.0% of the potential donors for each endpoint, respectively. In summary, these results demonstrated that an AMH concentration of approximately 700pgmL−1 can be used to select donors with higher oocyte yield and thus to increase IVEP outcomes in Gir heifers. This research was supported by Fazendas do Basa, Fapemig CVZ APQ 03430-17.


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&lt;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 13 (1) ◽  
Author(s):  
Eri Furukawa ◽  
Tomoyuki Masaki ◽  
Kenichiro Sakaguchi ◽  
Min Bo ◽  
Yojiro Yanagawa ◽  
...  

Abstract Background The timing of the first postpartum ovulation is an important factor affecting the timing of estrous resumption in dairy cows. The first postpartum ovulation is delayed in cows producing large amounts of milk with an intensive negative energy balance. The antral follicle count (AFC) and serum anti-Müllerian hormone concentrations are known to be indicators of the ovarian reserve, which is the number and quality of follicles left in a pair of ovaries and known as an indicator of female fertility. Cows with higher AFC have been proven to show higher pregnancy rate and shorter calving to conception intervals; however, the relationship between the timing of the first postpartum ovulation and ovarian reserve remains unclear. Therefore, this study examined the relationships between postpartum follicular dynamics, the ovarian cycle, nutritional status, and ovarian reserve. Methods Transrectal ultrasonography was conducted from calving to 70–120 days in milk (DIM) in 26 cows to monitor AFC, follicular dynamics and the ovarian cycle. Body weight (BW) and milk yield were used as indicators of nutritional status. Results The first postpartum ovulation was significantly later in cows with low AFC (< 25) than in those with high AFC (≥25), while changes in BW from calving to the nadir and milk production were similar in both groups. The present results also suggested that cows with low AFC and a delayed first postpartum ovulation had a shorter first ovarian cycle after the first postpartum ovulation. The mean DIM of the first postpartum artificial insemination (AI) and days open (days from calving to AI with which pregnancy was achieved) were similar in high and low AFC groups. Conclusions The first postpartum ovulation was significantly earlier in cows with high AFC than in those with low AFC. The assumed reason for this result was higher sensitivity to luteinizing hormone and larger androstenedione and estradiol production in follicles in high AFC cows. Therefore, cows with high AFC may be more fertile than those with low AFC while their milk production increase and BW decrease; it means they are in negative energy balance. (340/350 words)


2005 ◽  
Vol 17 (2) ◽  
pp. 234 ◽  
Author(s):  
R. Tribulo ◽  
E. Balla ◽  
L. Cutaia ◽  
G.A. Bo ◽  
P.S. Baruselli ◽  
...  

Although several studies have investigated the relationship between circulating progesterone and pregnancy rates in cattle, the beneficial effect of treatments that increase progesterone concentrations, by insertion of a progesterone (P4) releasing device or induction of an accessory CL with hCG, GnRH, or LH treatment, has resulted in inconsistent effects on pregnancy rates in embryo recipients. An experiment was designed to evaluate the effect of hCG or GnRH treatment, given at the time of embryo transfer without estrus detection, on pregnancy rates in recipients treated with intrauterine P4-releasing devices, estradiol benzoate (EB), and eCG. The experiment was performed in two replicates; non-lactating Bos taurus × Bos indicus crossbred beef cows with a body condition score between 2.5 to 3.5 (1-to-5 scale) were used (replicate 1, n = 180; replicate 2, n = 140). All cows received 1 g of P4 via a P4-releasing device (DIB, Syntex, Argentina) and 2 mg EB i.m. (Syntex) on Day 0, and 400 IU of eCG i.m. (Novormon 5000, Syntex) plus 150 μg d(+)cloprostenol i.m. (Ciclase, Syntex) on Day 5. DIBs were removed on Day 8 and all cows received 1 mg EB i.m. on Day 9. Recipients were not observed for signs of estrus, and those >1 CL, or a single CL with an area >256 mm2, received 195 Grade 1 and 46 Grade 2 frozen/thawed “direct transfer” embryos on Day 17. At the time of embryo transfer, recipients were randomly allocated to 1 of 3 treatment groups to receive 1500 IU hCG (Ovusyn, Syntex), 50 μg Lecirelina (GnRH, Gonasyn, Syntex), or no treatment (control) at that time. Ovarian ultrasonography was performed on Day 0 to determine ovarian status (only cows with a CL or a follicle >10 mm and uterine tone were used), on Day 17 to measure CL area, and 40 days after embryo transfer to determine pregnancy status. Data were analyzed by logistic regression and the effects of replication, technician, treatment, and embryo quality were considered in the model. From the 320 recipients treated with a DIB plus EB and eCG, 241 (75.3%) were selected to receive an embryo. Nine (3.7%) and 1 (0.4%) of the selected recipients had 2 and 3 CL, respectively. Pregnancy rates did not differ between replicates (replicate 1: 80/140, 57.1%; and replicate 2: 57/101, 56.4%; P = 0.84), technicians (technician 1: 65/118, 55.1%; and technician 2: 72/123, 58.5%; P = 0.64), or treatments (hCG: 43/80, 53.8%; GnRH: 45/83, 54.2%; and control: 49/78, 62.8% P = 0.99). However, pregnancy rates were higher (P = 0.001) in recipients receiving Grade 1 embryos (121/195, 62.1%) than in those receiving Grade 2 embryos (16/46, 34.8%). GnRH or hCG treatment at the time of embryo transfer did not increase pregnancy rates in recipients synchronized with P4 releasing devices, EB, and eCG. Research was supported by Syntex S.A., Estancia El Mangrullo S.A., and Agencia Cordoba Ciencia S.E.


2020 ◽  
pp. 2153-2162
Author(s):  
Suellen Miguez Gonzalez ◽  
Igor Emanuel Gomes Assunção ◽  
James Duarte ◽  
Carlos Henrique Andrade Oliveira ◽  
Tales André Guedes ◽  
...  

The objective of this study was to evaluate the efficiency and cost of two distinct hormonal protocols for induction of puberty in Bos indicus heifers in the western Amazon region. Nelore prepubertal heifers (n = 127) aged 20 to 24 months (21 ± 0.3 months) and weighing 300 to 340 kg (318 ± 7 kg) were submitted to two distinct protocols for induction of cyclicity. Females were previously submitted to two ovarian ultrasound examinations (12-day interval) to verify the absence of the corpus luteum (CL). Then, the heifers were divided into two experimental groups: G-CIDR/EC (n = 54) and G-P4/EC (n = 73). The G-CIDR/EC group utilized a CIDR® for 12 days and on the day of its withdrawal, 0.6 mg of estradiol cypionate (IM) was administered. The G-P4/EC group received 150 mg of injectable progesterone (IM) and one injection of 0.6 mg EC 12 days after the progesterone injection. Twelve days after the end of the hormonal protocols, the heifers were submitted to another ultrasound evaluation for identification of cyclicity (ovulatory follicle or CL). These females were then submitted to a conventional protocol of synchronization of ovulation for timed artificial insemination (TAI). Only heifers responsive to puberty induction (G-CIDR/EC (n=30) and G-P4/EC (n=51)) were included in the TAI protocol. After seven days of insemination, both groups were exposed to natural breeding. In addition, an economic analysis was performed to evaluate cyclicity induction, the TAI protocol, and pregnancy in both groups. The G-CIDR/EC group showed 81.48% (44/54) of females responsive to induction of cyclicity (presence of CL) while the G-P4/EC group obtained 86.3% (63/73; p=0.463). Regarding the conception rate to TAI and to bull (natural breeding), the G-CIDR/EC group displayed 43.33% (13/30) and 33.33% (10/30), respectively, and the G-P4/EC group exhibited 54.9% (28/51) and 39.22% (20/51), respectively. The overall pregnancy rate (TAI+Bull) was 76.67% (23/30) in the G-CIDR/EC group compared to 94.12% (48/51; P=0.023) in the G-P4/EC group. The cost of the hormonal protocol to cyclicity induction resulted in an economy of 42.8% for injectable P4 compared to the intravaginal P4 group. In addition, the final cost of cyclic induction associated with TAI was 34% lower in the G-P4/EC group compared to the G-CIDR/EC group. We concluded that both cycling induction protocols were efficient in Bos indicus heifers from the western Amazon. However, injectable P4 provided a higher conception rate and lower pregnancy cost at the end of the reproductive season.


Author(s):  
Julia Schiffner ◽  
Judith Roos ◽  
David Broomhead ◽  
Joseph van Helden ◽  
Erhard Godehardt ◽  
...  

AbstractBackground:The study aim was to validate Beckman Coulter’s fully automated Access Immunoassay System (BC Access assay) for anti-Müllerian hormone (AMH) and compare it with Beckman Coulter’s Modified Manual Generation II assay (BC Mod Gen II), with regard to cycle AMH fluctuations and antral follicle counts.Methods:During one complete menstrual cycle, transvaginal ultrasound was performed on regularly menstruating women (n=39; 18–40years) every 2 days until the dominant ovarian follicle reached 16mm, then daily until observed ovulation; blood samples were collected throughout the cycle. Number and size of antral follicles was determined and AMH levels measured using both assays.Results:AMH levels measured by the BC Access assay vary over ovulatory menstrual cycles, with a statistically significant pre-ovulatory decrease from –5 to +2 days around objective ovulation. Mean luteal AMH levels were significantly lower (–7.99%) than mean follicular levels but increased again towards the end of the luteal phase. Antral follicle count can be estimated from AMH (ng/mL, BC Access assay) concentrations on any follicular phase day. BC Access assay-obtained AMH values are considerably lower compared with the BC Mod Gen II assay (–19% on average); conversion equation: AMH BC Access (ng/mL)=0.85 [AMH BC Mod Gen II (ng/mL)]Conclusions:AMH levels vary throughout the cycle, independently of assay utilised. A formula can be used to convert BC Access assay-obtained AMH levels to BC Mod Gen II values. The number of antral follicles can be consistently estimated from pre-ovulatory AMH levels using either assay.


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