Alterations in follicular maturation associated with within-breed variation in ovulation rate in Chios sheep

1997 ◽  
Vol 46 (3-4) ◽  
pp. 223-235 ◽  
Author(s):  
M. Avdi ◽  
P. Chemineau ◽  
M.A. Driancourt
Keyword(s):  
Ovulation Rate ◽  
Follicular Maturation ◽  
Chios Sheep

The follicular microenvironment in low (++) and high (I+B+) ovulation rate ewes

Reproduction ◽  
2020 ◽  
Vol 159 (5) ◽  
pp. 585-599
Author(s):  
Zaramasina L Clark ◽  
Derek A Heath ◽  
Anne R O’Connell ◽  
Jennifer L Juengel ◽  
Kenneth P McNatty ◽  
...  
Keyword(s):  
Follicular Fluid ◽  
Cumulus Cell ◽  
Single Copy ◽  
Oocyte Quality ◽  
Ovulation Rate ◽  
Fluid Composition ◽  
Embryo Survival ◽  
Expression Levels ◽  
Follicular Maturation ◽  
Metabolic Substrates

Ewes with single copy mutations in GDF9, BMP15 or BMPR1B have smaller preovulatory follicles containing fewer granulosa cells (GC), while developmental competency of the oocyte appears to be maintained. We hypothesised that similarities and/or differences in follicular maturation events between WT (++) ewes and mutant ewes with single copy mutations in BMP15 and BMPR1B (I+B+) are key to the attainment of oocyte developmental competency and for increasing ovulation rate (OR) without compromising oocyte quality. Developmental competency of oocytes from I+B+ animals was confirmed following embryo transfer to recipient ewes. The microenvironment of both growing and presumptive preovulatory (PPOV) follicles from ++ and I+B+ ewes was investigated. When grouped according to gonadotropin-responsiveness, PPOV follicles from I+B+ ewes had smaller mean diameters with fewer GC than equivalent follicles in ++ ewes (OR = 4.4 ± 0.7 and 1.7 ± 0.2, respectively; P < 0.001). Functional differences between these genotypes included differential gonadotropin-responsiveness of GC, follicular fluid composition and expression levels of cumulus cell-derived VCAN, PGR, EREG and BMPR2 genes. A unique microenvironment was characterised in I+B+ follicles as they underwent maturation. Our evidence suggests that GC were less metabolically active, resulting in increased follicular fluid concentrations of amino acids and metabolic substrates, potentially protecting the oocyte from ROS. Normal expression levels of key genes linked to oocyte quality and embryo survival in I+B+ follicles support the successful lambing percentage of transferred I+B+ oocytes. In conclusion, these I+B+ oocytes develop normally, despite radical changes in follicular size and GC number induced by these combined heterozygous mutations.

scholarly journals The effect of H-2 region and genetic background on hormone-induced ovulation rate, puberty, and follicular number in mice

1991 ◽  
Vol 57 (1) ◽  
pp. 41-49 ◽  
Author(s):  
J. L. Spearow ◽  
R. P. Erickson ◽  
T. Edwards ◽  
L. Herbon
Keyword(s):  
Genetic Background ◽  
Follicular Development ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Ovulation Rate ◽  
Follicular Atresia ◽  
Linked Gene ◽  
Induced Ovulation ◽  
Follicular Maturation ◽  
Timing Of Puberty

SummaryWe have examined the effects of major histocompatibility (H-2) haplotypes and genetic background (all loci other than the H-2 region) on hormone-induced ovulation rate in congenic strains of mice. In comparison with the H-2a haplotype, the H-2b haplotype increased hormone-induced ovulation rate 92% on the A/J (A) genetic background. However, H-2 haplotype did not affect hormone-induced ovulation rate on the C57BL/10J (C57) genetic background. The H-2b-linked gene(s) increased hormone-induced ovulation rate on the A/J genetic background largely by (1) enhancing the maturation of follicles in response to pregnant mare's serum gonadotrophin (PMSG) and (2) altering the stages of follicular development which can be induced to ovulate in response to human chorionic gonadotrophin (hCG). The observed effects of H-2 on hormone-induced ovulation rate were not explained by differences in the timing of puberty, the number of follicles present in untreated females, or the incidence of follicular atresia. The effect of genetic background on hormone-induced ovulation rate was much greater than was the effect of the H-2 region. We found that hormone-induced ovulation rate was five- to six-fold higher on the C57 genetic background than on the A genetic background. The C57 genetic background increased hormone-induced ovulation rate by (1) enhancing the induction of follicular maturation in response to gonadotropins and (2) by reducing the incidence of follicular atresia.

scholarly journals Characteristics and experiences of Chios breed

1988 ◽  
Vol 60 (6) ◽  
pp. 576-584
Author(s):  
N. P. Zervas ◽  
J. Hatjiminaoglou ◽  
A. Georgoudis
Keyword(s):  
Milk Production ◽  
Milk Yield ◽  
Carcass Characteristics ◽  
Ovulation Rate ◽  
Sheep Breed ◽  
Early Maturing ◽  
Total Milk ◽  
Chios Sheep ◽  
Greek Island

Discussed are the reproductive and productive characteristics of the dairy and prolific Chios sheep breed, originating from the homonymous Greek island. Besides the island, the breed is also raised in the Greek mainland, the westcoast of Turkey and in Cyprus. It is early maturing, with long reproductive reason and lambing period, extending from October to March. Inspite its high ovulation rate, repeatability estimates do not suggest the presence of fecundity genes. The average prolificacy ratio ranges between 1.80 and 2.0, with triplets and quadruplets not uncommon. The average exploitable milk yield varies between 180 and 200 kg, with occasionally reported productions of up to 400 and 500 kg. Repeatabilities of prolificacy and milk production based on island data were found 0.15 and 0.40, respectively. Heritability of milk yield from the island was 0.31 and 0.40, respectively, for second and third lactations. Recent estimates from Cyprus report values of 0.30 and 0.39 for 90-day milk and total milk yield, respectively. Other parameters and information on udder (mechanical milking), growth, and carcass characteristics as well as on crossbreeding trials are also reported. Some considerations are given with regard to potential and valorization of this highly productive sheep breed.

Silage for flushing ewes

1983 ◽  
pp. 196-202
Author(s):  
J.M. Hayman ◽  
J.M. Munro
Keyword(s):  
Ovulation Rate

Keyword: wilted silage, flushing, ovulation rate

Relationship between ovulation rate and embryonic characteristics in gilts at 35 d of pregnancy

2017 ◽  
Vol 95 (7) ◽  
pp. 3160
Author(s):  
C. L. A. Da Silva ◽  
M. L. W. J. Broekhuijse ◽  
B. F. A. Laurenssen ◽  
H. A. Mulder ◽  
E.F. Knol ◽  
...  
Keyword(s):  
Ovulation Rate

EFFECT OF AROMATASE INIBITOR IN OVULATION INDUCTION IN FETILE WOMEN WITH POLYCYSTIC OVARY SYNDROME

2014 ◽  
pp. 86-93
Author(s):  
Minh Tam Le
Keyword(s):  
Polycystic Ovary Syndrome ◽  
Ovulation Induction ◽  
Polycystic Ovary ◽  
Endometrial Thickness ◽  
Statistical Significance ◽  
Ovulation Rate ◽  
Normal Body Mass Index ◽  
Ovary Syndrome ◽  
Group I ◽  
First Choice

Backgrounds: Polycystic Ovary Syndrome (PCOS) is one of the most common causes of female infertility due to ovulation disorders. Clomiphene citrate (CC) is a first choice to restore ovulation but it has some side effects by estrogen receptor down-regulation. Aromatase inhibitor (AI) is a newer class of drugs which increases the production of endogenous FSH to stimulate ovulation. Subjects and methods: randomized control trial to compare 64 cases of infertile women with PCOS examined at the Hue University Hospital, alternately used AI (group I) or CC (group II) for ovulation induction from day 2 cycle. Follow-up follicle growth, endometrium and ovulation via ultrasound. Evaluation were done on 10th day cycle, day of hCG trigger and after administration of hCG. Results: Total of 64 PCOS cases distributed into 2 groups using alternatively AI and CC had similar characteristics with average age of 28.8 ± 4.6, the majority were primary infertility (84.4%), infertility duration was 2.6 ± 2.4 years, 85.9% had oligomenorrhrea or amenorrhea, normal body mass index accounts for 60.9% and 21.9% was lean. Evaluation of both groups on day 10 revealed no differences in the dominant follicle and endometrial thickness. Number of days until the follicle mature appears to be shorter in AI group (15.1 ± 2.9) compared to the CC group (16.5 ± 2.8) with statistical significance. The number of mature follicles in 2 groups were not different at a rate of 81.3% (AI) and 84.4% (CC) but a higher proportion of single mature follicle in the AI ​​group (71.9%) compared with the CC group (65.7%) and There is no case with 3-4 mature follicles in the AI group. The rate of thin endometrium (<8 mm) in the AI group (25%) was lower than the CC group (53.1%) with statistically significance and higher ovulation rate (68.8%) compared with the CC group (56.3%) but have not found statistically significant. Conclusion: Two drugs AI and CC potentially induce follicle development and ovulation similarly, but AI has the potential to be more effective than CC on factors such as the shorter stimulation duration, increasing rate of single follicle, limiting multiple pregnancies, improve endometrial thickness and higher ovulation rate. More researches are needed with a larger sample size to clarify the statistical significance of differences.

scholarly journals 140 Effect of hCG on the last day of the 5-d CIDR-Synch and/or on day 5 of the estrous cycle on luteal dynamics in recipient Holstein heifers

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 112-113
Author(s):  
Marcelo Siqueira El Azzi ◽  
Everardo Anta Galvan ◽  
Teresita Valdes Arciniega ◽  
Iago Leão ◽  
Rodrigo Sala ◽  
...  
Keyword(s):  
Estrous Cycle ◽  
Ovulation Rate

Abstract The objective was to determine the effect of hCG (3,300 IU) administered on days 0 and/or 5 of the estrous cycle on total luteal area (TLA) and circulating concentrations of progesterone (P4) in recipient heifers. All heifers (n = 232; BCS = 3.3 ± 0.2) were synchronized with a 5d CIDR-Synch protocol (d-8: used CIDR inserted; d-3: CIDR removed and PGF2α treatment; d0: 100µg GnRH or hCG). Heifers were randomly assigned to four treatments: control, hCGd0, hCGd5, and hCGd0&5. Controls were treated with GnRH on d0, while hCGd0 received hCG on d0. hCGd5 heifers were treated with GnRH on d0 and hCG on d5, while hCGd0&5 received hCG on d0 and 5. Ovaries were scanned by ultrasound on d0, 5, and 12. Blood was collected on d0, 5, 7, and 12. Synchronization rate (94%) did not differ (P = 0.94) by treatment. Treatment differences were only tested in synchronized heifers (n = 218). Proportion of heifers with 1 or 2+ CL on d5 did not differ (P = 0.10) for hCG d0 treatments (hCGd0 + hCGd0&5) vs. GnRH d0 treatments (controls + hCGd5). However, heifers treated with hCG on d0 had greater (P &lt; 0.01) TLA and P4 on d5 vs. treatments with GnRH on d0 (311 ± 13 vs. 257 ± 9 mm2; and 2.39 ± 0.15 vs. 1.90 ± 0.09 ng/mL). Ovulation rate for d5 hCG did not differ (P = 0.63) for hCGd5 vs. hCGd0&5 (93 vs. 84%). Controls had the lowest serum P4 on d7 and 12. In contrast, hCGd0&5 had the highest serum P4 on d7 (Table 1). Serum P4 on d7 did not differ for hCGd0 vs. hCGd5. On d12, serum P4 and TLA were not different for hCGd5 vs. hCGd0&5. These data indicate that hCG can be used on d0 to induce an increase in serum P4 on d5 compared to GnRH. However, only heifers treated with hCG on d5 achieved mean serum P4 &gt; 8ng/mL.

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