scholarly journals Intensified Use of Reproductive Technologies and Reduced Dimensions of Breeding Schemes Put Genetic Diversity at Risk in Dairy Cattle Breeds

Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1903
Author(s):  
Anna-Charlotte Doublet ◽  
Gwendal Restoux ◽  
Sébastien Fritz ◽  
Laura Balberini ◽  
Guillaume Fayolle ◽  
...  

In the management of dairy cattle breeds, two recent trends have arisen that pose potential threats to genetic diversity: the use of reproductive technologies (RT) and a reduction in the number of bulls in breeding schemes. The expected outcome of these changes, in terms of both genetic gain and genetic diversity, is not trivial to predict. Here, we simulated 15 breeding schemes similar to those carried out in large French dairy cattle breeds; breeding schemes differed with respect to their dimensions, the intensity of RT use, and the type of RT involved. We found that intensive use of RT resulted in improved genetic gain, but deteriorated genetic diversity. Specifically, a reduction in the interval between generations through the use of ovum pick-up and in vitro fertilization (OPU-IVF) resulted in a large increase in the inbreeding rate both per year and per generation, suggesting that OPU-IVF could have severe adverse effects on genetic diversity. To achieve a given level of genetic gain, the scenarios that best maintained genetic diversity were those with a higher number of sires/bulls and a medium intensity of RT use or those with a higher number of female donors to compensate for the increased intensity of RT.

2019 ◽  
Vol 51 (1) ◽  
Author(s):  
Anna-Charlotte Doublet ◽  
Pascal Croiseau ◽  
Sébastien Fritz ◽  
Alexis Michenet ◽  
Chris Hozé ◽  
...  

Abstract Background In France, implementation of genomic evaluations in dairy cattle breeds started in 2009 and this has modified the breeding schemes drastically. In this context, the goal of our study was to understand the impact of genomic selection on the genetic diversity of bulls from three French dairy cattle breeds born between 2005 and 2015 (Montbéliarde, Normande and Holstein) and the factors that are involved. Methods We compared annual genetic gains, inbreeding rates based on runs of homozygosity (ROH) and pedigree data, and mean ROH length within breeds, before and after the implementation of genomic selection. Results Genomic selection induced an increase in mean annual genetic gains of 50, 71 and 33% for Montbéliarde, Normande and Holstein bulls, respectively, and in parallel, the generation intervals were reduced by a factor of 1.7, 1.9 and 2, respectively. We found no significant change in inbreeding rate for the two national breeds, Montbéliarde and Normande, and a significant increase in inbreeding rate for the Holstein international breed, which is now as high as 0.55% per year based on ROH and 0.49% per year based on pedigree data (equivalent to a rate of 1.36 and 1.39% per generation, respectively). The mean ROH length was longer for bulls from the Holstein breed than for those from the other two breeds. Conclusions With the implementation of genomic selection, the annual genetic gain increased for bulls from the three major French dairy cattle breeds. At the same time, the annual loss of genetic diversity increased for Holstein bulls, possibly because of the massive use of a few elite bulls in this breed, but not for Montbéliarde and Normande bulls. The increase in mean ROH length in Holstein may reflect the occurrence of recent inbreeding. New strategies in breeding schemes, such as female donor stations and embryo transfer, and recent implementation of genomic evaluations in small regional breeds should be studied carefully in order to ensure the sustainability of breeding schemes in the future.


2012 ◽  
Vol 52 (3) ◽  
pp. 107 ◽  
Author(s):  
J. E. Pryce ◽  
H. D. Daetwyler

High rates of genetic gain can be achieved through (1) accurate predictions of breeding values (2) high intensities of selection and (3) shorter generation intervals. Reliabilities of ~60% are currently achievable using genomic selection in dairy cattle. This breakthrough means that selection of animals can happen at a very early age (i.e. as soon as a DNA sample is available) and has opened opportunities to radically redesign breeding schemes. Most research over the past decade has focussed on the feasibility of genomic selection, especially how to increase the accuracy of genomic breeding values. More recently, how to apply genomic technology to breeding schemes has generated a lot of interest. Some of this research remains the intellectual property of breeding companies, but there are examples in the public domain. Here we review published research into breeding scheme design using genomic selection and evaluate which designs appear to be promising (in terms of rates of genetic gain) and those that may have unfavourable side-effects (i.e. increasing the rate of inbreeding). The schemes range from fairly conservative designs where bulls are screened genomically to reduce numbers entering progeny testing, to schemes where very large numbers of bull calves are screened and used as sires as soon as they reach sexual maturity. More radical schemes that incorporate the use of reproductive technologies (in juveniles) and genomic selection in nucleus herds are also described. The models used are either deterministic and more recently tend to be stochastic, simulating populations of cattle. A key driver of the rate of genetic gain is the generation interval, which could range from being similar to that in conventional testing (~5 years), down to as little as 1.5 years. Generally, the rate of genetic gain is between 12% and 100% more than in conventional progeny testing, while the rate of inbreeding tends to be lower per generation than in progeny testing because Mendelian sampling terms can be estimated more accurately. However, short generation intervals can lead to higher rates of inbreeding per year in genomic breeding programs.


2021 ◽  
Author(s):  
Cornelius Nwoga ◽  
Nnanna Ikeh ◽  
Matthew Onodugo ◽  
Paul Baiyeri ◽  
Ndubuisi Machebe

Assisted reproductive technologies (ART) that have come to stay and are still being improved upon in developed countries are still in their infancy stage in developing countries like Nigeria. Nigeria’s cattle population is estimated to be around 18.4 million. The number is far insufficient to meet the country’s demand for meat, milk, and other cow products, let alone contribute to GDP. N’dama and Muturu are both Nigerian breeds that are resistant to trypanosomosis. They are humpless longhorn and humpless shorthorn types of beef cattle. The dairy and beef cow industries’ inadequate adoption of ART is partly to blame for Nigeria’s low cattle output. Sex determination, multiple-ovulation and embryo transfer (MOET), oestrus synchronization, artificial insemination (AI), in vitro fertilization (IVF), cloning, and genetic engineering are all examples of assisted reproductive technologies. It has been reported in humans, rodents and domestic animals, abnormal fetuses, newborns and adult offspring arise from ART. Improper matching of breeding animals mostly leads to overfat calves. This review centers on the applications and potentials of ART in the production of trypanotolerant N’dama and Muturu cattle breeds. Some unorthodox medicines which have proven effective in human reproduction can circumvent the shortfalls in the adoption of ART.


2016 ◽  
pp. 166-170
Author(s):  
Y.V. Masliy ◽  
◽  
I.O. Sudoma ◽  
P.S. Mazur ◽  
D.A. Mykytenko ◽  
...  

The objective: to study the possibility of using frozen blastocysts for biopsy and genetic testing and performance measurement transfer euploeded 5–7-day-old embryos after thawing, biopsies, refreezing and thawing in patients with unsuccessful implantation. Patients and methods. The object of the study was the group of patients with repeated failure of implantation (4) in programs of auxiliary reproductive technologies (ART), subject to transfer to the uterus in total (i.e. in all the programs) for at least 6 good quality embryos based on morphological characteristics). All women had sufficient ovarian reserve. The patient was treated for infertility within the ART programs of the clinic of reproductive medicine "Nadiya" in the period from 2006 to 2016. The sample included couples who were not carriers of chromosomal rearrangements, without anomalies of the uterus (congenital and acquired: a doubling of the uterus, one-horned uterus, intrauterine membrane, synechia, submucous myoma of the uterus). All women had a positive ovarian response to controlled stimulation with gonadotropins (at least 7 oocytes) and a sufficient number of cryopreserved embryos. The first group (G1) included 64 women who trophectodermal a biopsy was performed on fresh blastocysts (in a loop controlled ovarian hyperstimulation). The second group (G2) were included 31 women who underwent thawing previously cryopreserved blastocysts trophectodermal re-biopsy and vitrification of blastocysts. Results. It was found that the performance of transfers euploid embryos that were vitrified, bioptrone and revitriphted, a little lower than those that were bioptrone fresh and vitrified only once. At the same time computationa genetic diagnosis previously vitrified blastocysts using comparative genome hybridization in patients with recurrent failed implantation allows to obtain a reasonable pregnancy rate (58%), implantation rate (33.3 %) and the birth of living children (45.1 %). Conclusion. Reprising biopropane embryos does not cause significant destructive impact and allows you to achieve pregnancy and birth of the alive child. Key words: in vitro fertilization, reusable unsuccessful implantation, a method of comparative genome hybridization, refreezing.


GYNECOLOGY ◽  
2018 ◽  
Vol 20 (1) ◽  
pp. 113-116
Author(s):  
L A Bagdasaryan ◽  
I E Korneyeva

The aim of the study is to systematically analyze the data available in the modern literature on the relationship between endometrial thickness and the frequency of pregnancy in the program of assisted reproductive technologies (ART). Materials and methods. The review includes data from foreign and domestic articles found in PubMed on this topic. Results. The article presents data on the relationship between the thickness of the endometrium and the frequency of pregnancy in ART programs. The greatest number of studies is devoted to the evaluation of the relationship between the thickness of the endometrium and the frequency of pregnancy on the day of the ovulation trigger. Data are presented on the existence of a correlation between the thickness of the endometrium measured on the day of the ovulation trigger and the frequency of clinical pregnancy, as well as data on the need to evaluate the structure of the endometrium and the state of subendometric blood flow. The importance of multilayered (three-layered) endometrium as a prognostic marker of success in in vitro fertilization/intracytoplasmic sperm injection programs in the ovum is emphasized. The conclusion. The thickness of the endometrium can not be used as an argument for canceling the cycle or abolishing embryo transfer to the uterine cavity. Further studies in this direction are needed with a study of the morphological and molecular genetic characteristics of the endometrium, which in the future will allow us to evaluate the relationship between the thickness of the endometrium and the probability of pregnancy.


Author(s):  
N.A. Altinnik , S.S. Zenin , V.V. Komarova et all

The article discusses the factors that determine the content of the legal limitations of pre-implantation genetic diagnosis in the framework of the in vitro fertilization procedure, taking into account international experience and modern domestic regulatory legal regulation of the field of assisted reproductive technologies. The authors substantiates the conclusion that it is necessary to legislate a list of medical indications for preimplantation genetic diagnosis, as well as the categories of hereditary or other genetic diseases diagnosed in the framework of this procedure.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sandra Monfort ◽  
Carmen Orellana ◽  
Silvestre Oltra ◽  
Mónica Rosello ◽  
Alfonso Caro-Llopis ◽  
...  

AbstractDevelopment of assisted reproductive technologies to address infertility has favored the birth of many children in the last years. The majority of children born with these treatments are healthy, but some concerns remain on the safety of these medical procedures. We have retrospectively analyzed both the fertilization method and the microarray results in all those children born between 2010 and 2019 with multiple congenital anomalies, developmental delay and/or autistic spectrum disorder (n = 486) referred for array study in our center. This analysis showed a significant excess of pathogenic copy number variants among those patients conceived after in vitro fertilization with donor oocyte with respect to those patients conceived by natural fertilization (p = 0.0001). On the other hand, no significant excess of pathogenic copy number variants was observed among patients born by autologous oocyte in vitro fertilization. Further studies are necessary to confirm these results and in order to identify the factors that may contribute to an increased risk of genomic rearrangements, as well as consider the screening for genomic alterations after oocyte donation in prenatal diagnosis.


2021 ◽  
Vol 10 (12) ◽  
pp. 2687
Author(s):  
Kaan Aydos ◽  
Oya Sena Aydos

Retrieving spermatozoa from the testicles has been a great hope for patients with non-obstructive azoospermia (NOA), but relevant methods have not yet been developed to the level necessary to provide resolutions for all cases of NOA. Although performing testicular sperm extraction under microscopic magnification has increased sperm retrieval rates, in vitro selection and processing of quality sperm plays an essential role in the success of in vitro fertilization. Moreover, sperm cryopreservation is widely used in assisted reproductive technologies, whether for therapeutic purposes or for future fertility preservation. In recent years, there have been new developments using advanced technologies to freeze and preserve even very small numbers of sperm for which conventional techniques are inadequate. The present review provides an up-to-date summary of current strategies for maximizing sperm recovery from surgically obtained testicular samples and, as an extension, optimization of in vitro sperm processing techniques in the management of NOA.


2018 ◽  
pp. 122-126
Author(s):  
I.A. Zhabchenko ◽  
◽  
O.R. Sudmak ◽  

The objective: to study the structure and frequency of complications of pregnancy, deliveries and perinatal outcomes in three groups of women: women with infertility and obesity, treated by application of in vitro fertilization (hereinafter IVF), pregnant women after IVF application with normal body weight, and pregnant women on the background of obesity which did not have an infertility in past history. Materials and methods. A retrospective analysis of 221 case histories of pregnancies and labors in women who were treated and gave birth in the Pregnancy and delivery pathology Department of SI «Institute of Pediatrics, Obstetrics and Gynecology named after Acad. O. M. Lukyanova of NAMS of Ukraine» for 2012 – 2016 years was carried out. Results. The overwhelming majority of pregnant women after IVF on the background of obesity are primaparas, who have a complicated obstetric history, hormonal changes in the form of progesterone deficiency predominantly and chronic inflammatory processes. Pregnancy with a combination of infertility, treated by the means of IVF application, and obesity, in most cases is accompanied by a long-term threat of termination of pregnancy (48.8%), threatening preterm deliveries (56%), placental dysfunction (41.5%), premature rupture of the amniotic membranes (41.5%), other problems during pregnancy, at the same time, every second woman (58.5%) had a combination of several complications, and required a long-term and repeated inpatient treatment (53.7%). The specific gravity of surgical delivery was 90%, and 16.2% of such deliveries were complicated by pathological blood loss. The number of preterm deliveries was 17.1%, with perinatal losses up to 11.3‰. Among full-term newborns 21.3% of newborns had malnutrition of the I degree and 17% of them had hypoxic-ischemic lesion of CNS. Conclusion. The course of pregnancy, delivery and the postpartum period in the studied contingent of women has a significant frequency of complications, mainly the coinciding ones, which affects on the consequences of perinatal outcomes and requires further study of this problem and the development of differentiated algorithms for antenatal observation. Key words: pregnancy, obesity, in vitro fertilization, complications, delivery, newborn.


Author(s):  
Georgina L. Jones ◽  
Victoria Lang ◽  
Nicky Hudson

AbstractThe year 2018 marked 40 years since the birth of Louise Brown, the first baby born as a result of pioneering in vitro fertilization (IVF) treatment. Since then, advances have seen a wide range of reproductive technologies emerge into clinical practice, including adjuvant treatments often referred to as IVF “add-ons.” However, these “optional extras” have faced growing criticism, especially when they have often come at additional financial cost to the patient and have little evidence supporting their efficacy to improve pregnancy or birth rates. Despite this, according to the latest national patient survey by the Human Fertilisation and Embryology Authority, three quarters of patients who had fertility treatment in the United Kingdom in the past two years had at least one type of treatment add-on highlighting the growing demand for these interventions. This article uses a psychosocial perspective to consider the motivations behind patient and clinician behavior along with the wider societal and economic factors that may be impacting upon the increase in the use of adjuvant treatments in fertility clinics more widely. It suggests the reasons fertility patients use unproven “optional extras” are complex, with interpersonal, psychological, and social factors intertwining to generate an increase in the use of IVF add-ons.


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