Fertilization and return rates in Bungaree and Peppin Merino ewes mated in autumn

1971 ◽  
Vol 11 (52) ◽  
pp. 478
Author(s):  
JR Giles
Keyword(s):  
Genital Tract ◽  
Significant Contribution ◽  
Fertilization Rate ◽  
Return Rate ◽  
Fallopian Tubes ◽  
Fertilization Failure ◽  
Return Rates ◽  
Fertilization Rates ◽  
Embryonic Loss ◽  
The Difference

A series of studies was conducted in 1968 and 1969 to compare fertilization rates, return rate, and sperm distribution in the genital tract in Bungaree and Peppin Merino ewes. Differences in lambing rates of the two ewe strains were demonstrated, but there was no major difference in fertilization rate in either year. A significantly higher proportion of Bungaree ewes had less than 1000 sperm in the fallopian tubes 24 hours after service, but there were no significant differences in any other character examined. Contrary to an earlier report, fertilization failure is unlikely to have been a major cause of a difference in the fertility of the two strains in the two years, and embryonic loss is likely to have made a significant contribution to the difference in their fertility.

P–279 Effect of Ca2+ ionophore A23187 (calcymicin) on fertilization rates, embryo development and pregnancy in human assisted reproduction cycles

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
G Lópe. Ruiz ◽  
C Olmed. Illueca ◽  
M Bare. Gómez ◽  
S Roy. Bolea ◽  
L Aba. d. Velasco ◽  
...  
Keyword(s):  
Assisted Reproduction ◽  
Fertilization Rate ◽  
Control Group ◽  
Ionophore A23187 ◽  
Oocyte Activation ◽  
Fertilization Failure ◽  
Reproductive Outcomes ◽  
Blastocyst Formation ◽  
Fertilization Rates ◽  
Embryo Kinetics

Abstract Study question Does Calcymicin improve reproductive outcomes of ICSI cycles in cases of fertilization failure and/or embryo blockage indications? Summary answer The application of the Calcymicin after ICSI improves reproductive outcomes, especially in cases with clinical indication of fertilization failure. What is known already According to the bibliography, deficiencies in the oocyte activation process frequently lead to failed ICSI cycles, and these can be corrected by increasing initial levels of calcium (Ca2+) in the oocyte using assisted oocyte activation techniques (AOA), such as the use of Ca2+ ionophores. Ca2+ Ionophores have been shown to trigger an initial Ca2+ spike in the ooplasm that activates Ca2+/Calmodulin dependent protein kinase II, which initiates the cascade of cellular events leading to oocyte activation. Previous results suggest that Ca2+ ionophore treatment can give live offspring after failed ICSI cycles. Study design, size, duration 270 oocytes collected from 17 patients who presented cycles with low fertilization rates and/or embryo blockage or poor quality embryos (according to ASEBIR’s embryo classification criteria) were retrospectively analyzed. Oocytes were divided into two groups, a control group that underwent conventional IVF/ICSI and another group that underwent an ICSI cycle with AOA. Study groups were defined according to clinical indications and subgroups according to AOA or control. All data were collected from 2017 until 2020. Participants/materials, setting, methods Among the 270 oocytes of the study sample, 142 belonged to the control group and 128 belonged to the AOA group. The AOA group oocytes were activated for 15 minutes immediately after ICSI using a prepared solution containing the Ca2+ ionophore A23187, CultActive© (Gynemed, Germany). Fertilization rate and type, blastocyst formation rate, blastocyst quality, embryo kinetics, and pregnancy rates were analyzed, all of them were compared to FIV/ICSI cycles without oocyte activation (control group). Main results and the role of chance In the analyses of the whole sample of oocytes, the AOA treatment gave a fertilization rate of 72.5%, which was significantly higher compared to 53.8% of the control cycles (p = 0.002). Good quality blastocysts and pregnancy rates were also significantly higher than the control (p = 0.01). In the group with an indication of fertilization failure, a significantly higher fertilization rate was recorded compared to the control (65% and 33%, respectively). A higher rate of abnormal embryos with three pronuclei was also found compared to the control (p < 0.001). There were no significant differences in blastocyst formation rates, quality, or embryo kinetics (p > 0.05). In the group with an indication of embryo blockage/poor embryo quality, a significantly higher rate of good quality blastocysts and lower blastulation time were recorded compared to the control (p < 0.05). Limitations, reasons for caution The safety of the AOA technique with Ca2+ ionophore has not been fully demonstrated. In our study, none of the newborns had malformations, and gestational weeks and birth weights were normal. However, further studies on the safety of this technique are needed to implement it routinely in human reproduction clinics. Wider implications of the findings: According to these findings, an increase in the initial levels of calcium in the oocyte through the application of the Ca2+ ionophore A23187 after ICSI improves the results of failed assisted reproduction cycles, especially in the case of those diagnosed with fertility failure, which is a clear indication for AOA. Trial registration number Not applicable

Studies in flock mating of sheep. 3. Effect of undernutrition of ewes during joining

1971 ◽  
Vol 11 (51) ◽  
pp. 375 ◽  
Author(s):  
AWH Braden
Keyword(s):  
Genital Tract ◽  
Mating Behaviour ◽  
Fertilization Rate ◽  
Early Embryo ◽  
Ovulation Rate ◽  
Medium Condition ◽  
Under Nutrition ◽  
Embryonic Loss ◽  
The Mean

One hundred five-year-old Merino ewes in medium condition (44 kg) were fed at one-third of the maintenance level from the start of joining until 3-4 weeks post-coitum (P.C.). The mean decrease in liveweight in the 3-4 weeks was 1.5 kg/week. One hundred similar ewes were fed so as to maintain liveweight. A ram was joined with each group during daylight hours for 15 days, and the course of mating observed constantly. Ewes were killed either 1-2 days p.c. or 24-38 days p.c. There was no evidence of an effect of the under-nutrition on mating behaviour, number of spermatoza in the ewe genital tract, fertilization rate (89 per cent for both) or early embryo losses (7 per cent and 3 per cent). The relatively low embryonic loss appeared to be related to the low ovulation rate (1.16).

Fertilization, sperm transport, and early embryonic loss in ewes grazed on cultivars of subterranean clover. (T. subterraneum)

1970 ◽  
Vol 21 (1) ◽  
pp. 107 ◽  
Author(s):  
cC Kaltenbach ◽  
HL Davies
Keyword(s):  
Subterranean Clover ◽  
Fertilization Rate ◽  
Reproductive Failure ◽  
Embryonic Survival ◽  
Sperm Transport ◽  
Fertilization Rates ◽  
Significant Difference ◽  
Embryonic Loss

The causes of infertility due to phyto-oestrogens were investigated in ewes which had grazed Dwalganup, Yarloop, Geraldton, Woogenellup, and Mount Barker cultivars of subterranean clover (T. subterraneum L.) for 5 years. At laparotomy, sperm transport was investigated by making counts of spermatozoa in the oviduct 22-26 hr post coitum; fertilization rates were checked 72 hr post coitum and embryonic survival at 27-31 days. A larger proportion of ewes on high oestrogen cultivars Dwalganup, Yarloop, and Geraldton) had low oviducal spermatozoa counts and the fertilization rate was significantly lower (P < 0.05) than in ewes grazed on low oestrogen cultivars (Woogenellup and Mount Barker) (44% v. 63 %). There was no statistically significant difference in embryonic survival between these groups. Merino ewes had fewer oviducal spermatozoa and a lower (P < 0.05) fertilization rate than Border Leicester x Merino ewes. Impaired sperm transport is considered to be the reason for reproductive failure in the ewes that had grazed the high oestrogen cultivars of subterranean clover.

scholarly journals Early Rescue Intracytoplasmic Sperm Injection in Partial Fertilization Failure Is Necessary and Safe: A Retrospective Analysis of 1223 Patients

2020 ◽  
Author(s):  
Jun Zeng ◽  
Zhongyuan Yao ◽  
Yeqing Zhang ◽  
Fen Tian ◽  
Tingting Liao ◽  
...  
Keyword(s):  
Polar Body ◽  
Fertilization Rate ◽  
Fertilization Failure ◽  
Short Term ◽  
Vitro Fertilization ◽  
Long Term Follow Up ◽  
The Difference ◽  
Second Polar Body

Abstract BACKGROUND: Total or near total fertilization failure remains inevitable in conventional in vitro fertilization (IVF). The experts searched for the release of the second polar body 6 h after initial insemination, and rescued those oocytes with unclear second polar body by ICSI (early R-ICSI). Studies found that early R-ICSI can effectively decrease complete IVF fertilization failure and excessive ICSI treatment.METHODS: We performed a retrospective study in 16,769 patients (short-term IVF, n=12,094; ICSI, n=3,452; early R-ICSI, n=1,223) who received IVF/ICSI treatment in our hospital from January 2009 to October 2018. Fertilization and clinical outcomes were compared among those three groups.RESULTS: When considering the R-ICSI embryos in the early R-ICSI group independently, the rates of fertilization and day-3 cleaved embryos in 2PN oocytes were comparable, the rates of fertilization (2PN) and high-quality embryos were lower, whereas the multi-PN fertilization rate (3.27%) was significantly higher than the ICSI group (1.26%). The difference of clinical pregnancy rate between the part of transferred R-ICSI embryos (40.81%) and the ICSI group (44.73) remained nonsignificant. Furthermore, the rate of congenital birth defects in the early R-ICSI group (0.99%) was not significantly different from those in the short-term IVF (0.76%) and ICSI groups (1.07%).CONCLUSIONS: Despite the multi-PN fertilization rate, our study highlights early R-ICSI as a safe and effective alternative in assisted reproduction to reduce ICSI utilization. Additional large amount and long-term follow-up studies are needed to further validate the use of early R-ICSI.

Fertilization and embryo mortality in Bungaree Merino ewes mated in autumn

1969 ◽  
Vol 9 (39) ◽  
pp. 377 ◽  
Author(s):  
JR Giles
Keyword(s):  
Fertilization Rate ◽  
Ovulation Rate ◽  
Low Fertility ◽  
Fertilization Failure ◽  
Similar Group ◽  
Expected Number ◽  
Embryo Mortality ◽  
Significant Difference ◽  
The Mean ◽  
The Difference

Fertilization and embryo mortality were examined in Bungaree ewes to determine their contribution to the known low autumn fertility of these ewes. A group of approximately 100 ewes was joined for 34 days in April with two Bungaree rams and a similar group was joined with two Peppin rams. Ewes were removed from the groups within two days of mating and half the mated ewes were laparotomized to determine ovulation rate and percentage of ova fertilized. Remaining ewes were allowed to lamb and embryo mortality was calculated as the difference between the expected number of fertilized eggs and the number of lambs born to ewes mated but not laparotomized. There was no significant difference between the groups in either fertilization rate or estimated embryo mortality. The mean fertilization rate was 53.3 per cent of ova recovered (53.4 per cent of ewes had fertilized ova) and embryo mortality was calculated to be 19.6 per cent of ova fertilized. The mean percentage of ewes losing all fertilized ova was calculated to be 7.8 per cent of ewes mated. It is suggested that fertilization failure is the major factor in the low fertility of these ewes.

scholarly journals Optimal Nitrogen Fertilization Rates in Winter Wheat Production as Affected by Risk, Disease, and Nitrogen Source

2004 ◽  
Vol 36 (1) ◽  
pp. 199-211 ◽  
Author(s):  
Roland K. Roberts ◽  
Jeremy T. Walters ◽  
James A. Larson ◽  
Burton C. English ◽  
Donald D. Howard
Keyword(s):  
Root Rot ◽  
Conservation Tillage ◽  
Fertilization Rate ◽  
N Fertilization ◽  
Wheat Production ◽  
Fertilization Rates ◽  
Net Returns ◽  
N Source ◽  
The Difference ◽  
Take All

Interactions among the nitrogen (N) fertilization rate, N source, and disease severity can affect mean yield and yield variance in conservation tillage wheat production. A Just-Pope model was used to evaluate the effects of N rate, N source, and disease on the spring N-fertilization decision. Ammonium nitrate (AN) was the utility-maximizing N source, regardless of risk preferences. The net-return-maximizing AN rate was 92 lb N/acre, providing $0.52/acre higher net returns than the best alternative N source (urea). If a farmer could anticipate a higher-than-average Take-All Root Rot infection, the difference in optimal net returns between AN and urea would increase to $35.11/acre.

scholarly journals Effect of Time of Insemination on the Distribution of Spermatozoa in the Genital Tract in Ewes

1969 ◽  
Vol 22 (5) ◽  
pp. 1283 ◽  
Author(s):  
PE Mattner ◽  
AWH Braden
Keyword(s):  
Genital Tract ◽  
Fertilization Rate ◽  
Cervical Mucus ◽  
Fallopian Tubes

Merino ewes were artificially inseminated during either early or late oestrus and were killed 4 or 24 hr after insemination. Insemination during late oestrus resulted in fewer spermatozoa in the cervix, the uterus, and the fallopian tubes and in a lower fertilization rate. Increased resistance of the cervical mucus to penetration by spermatozoa during late oestrus appeared to be responsible for these effects.

Earnings and Investment Differentials Between Migrants and Natives: A Study of Female Street Vendors in Bengaluru City

2021 ◽  
pp. 097542532199031
Author(s):  
Channamma Kambara ◽  
Indrajit Bairagya
Keyword(s):  
Labour Market ◽  
Decomposition Method ◽  
Significant Contribution ◽  
Street Vendors ◽  
Significant Difference ◽  
The Difference ◽  
Rate Of Returns

This article explores whether there exists any difference in the earnings of self-employed migrant and native street vendors in a metro city, and if so, in what ways this difference is prominent. In order to accomplish the objective, we have collected data from women street vendors from Bengaluru city. The results depict that although there is no significant difference in the earnings between native and migrant street vendors, a significant difference exists in the size of investments made by them, that is, to earn the same amount of income, migrants need to invest more than natives. Moreover, the results, based on the Oaxaca–Blinder decomposition method, indicate that the pre-labour market endowment factors do not make a significant contribution to the overall difference in the rate of returns. The difference, instead, mainly exists because of the coefficient differences, which can be attributed to discrimination.

scholarly journals Assessment of the Construction of a Climate Resilient City: An Empirical Study Based on the Difference in Differences Model

2021 ◽  
Vol 18 (4) ◽  
pp. 2082
Author(s):  
Zifeng Liang
Keyword(s):  
Significant Contribution ◽  
Evaluation Method ◽  
Regional Climate ◽  
Chinese Government ◽  
Infrastructure Development ◽  
Grey System ◽  
Difference In Differences ◽  
Climate Resilience ◽  
The Difference ◽  
The Impact

Facing climate risks has become a common problem for mankind and a topic of great importance for the Chinese government. To thoroughly implement the overall requirements for the construction of an ecological civilization and effectively improve the capacity of cities to adapt to climate change, China launched the pilot construction of “Climate Resilient Cities” in 2017. In this paper, 16 prefecture level cities in Anhui Province of China were selected as the research objects, and the multi-level grey system evaluation method was used to measure the climate resilience of these regions. We used the difference in differences method to evaluate the effect of the pilot policy of “Climate Resilient Cities.” The pilot policies of the “Climate Resilient Cities” showed a significant contribution to the regional climate resilience, and, after isolating the impact of other factors on the regional climate resilience, the pilot policies of the “Climate Resilient Cities” increased the climate resilience of the pilot cities by four percentage points. The pilot policies of the “Climate Resilient Cities” had a significant contribution to the urban infrastructure development and ecological space optimization, as well as non-significant impacts to the urban water security, emergency management capacity-building, and science and technology innovation initiatives.

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