Application of reproductive technologies to the improvement of dairy cattle genomic selection

2015 ◽  
Vol 19 (3) ◽  
pp. 277
Author(s):  
N. S. Yudin ◽  
K. I. Lukyanov ◽  
M. I. Voevoda ◽  
N. A. Kolchanov
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.


2014 ◽  
Vol 26 (1) ◽  
pp. 12 ◽  
Author(s):  
C. Ponsart ◽  
D. Le Bourhis ◽  
H. Knijn ◽  
S. Fritz ◽  
C. Guyader-Joly ◽  
...  

Genomic tools are now available for most livestock species and are used routinely for genomic selection (GS) in cattle. One of the most important developments resulting from the introduction of genomic testing for dairy cattle is the application of reasonably priced low-density single nucleotide polymorphism technology in the selection of females. In this context, combining genome testing and reproductive biotechnologies in young heifers enables new strategies to generate replacement and elite females in a given period of time. Moreover, multiple markers have been detected in biopsies of preimplantation stage embryos, thus paving the way to develop new strategies based on preimplantation diagnosis and the genetic screening of embryos. Based on recent advances in GS, the present review focuses on new possibilities inherent in reproductive technologies used for commercial purposes and in genetic schemes, possible side effects and beneficial impacts on reproductive efficiency. A particular focus is on the different steps allowing embryo genotyping, including embryo micromanipulation, DNA production and quality assessment.


2016 ◽  
Vol 6 (3) ◽  
pp. 321-329 ◽  
Author(s):  
N. S. Yudin ◽  
K. I. Lukyanov ◽  
M. I. Voevoda ◽  
N. A. Kolchanov

2021 ◽  
Vol 7 (1) ◽  
pp. 10-18
Author(s):  
Wilkister Nakami ◽  
◽  
Victor Tsuma ◽  

The human population is expected to double in Africa by 2030 and with it a consequent rise in demand for livestock products. Reproductive technologies improve livestock productivity however, uptake of the technologies has been low in Africa, yet this is where there is a dire need for livestock products as the human population surges. This study aimed to assess knowledge extent and understanding the use of assisted reproductive technologies in decision support for reproductive management of dairy cattle in Kenya. Dairy farmers and veterinary practitioners were interviewed using a questionnaire to obtain relevant data on knowledge, attitude and practices in the use of assisted reproductive technologies in reproductive management in dairy farms. Observable heat signs was the only method used by participants to ascertain estrus in a cow. Artificial insemination technique was adopted by all farmers as the breeding method of choice. The analysis highlighted that the respondents with low levels of formal education had less knowledge on reproductive technologies and displayed risky practices. Overall, a larger proportion of respondents indicated that the assisted reproductive technologies would be important in reproductive management. The relatively low levels of awareness, higher levels of education and a willingness to use the assisted reproductive technologies in reproductive management of dairy cattle strengthen the logic of improving productivity through the application of these assisted reproductive technologies as well as improve levels of awareness of reproductive management practices. Keywords: attitude, heat detection, knowledge, pregnancy diagnosis, practices, progesterone


2016 ◽  
Vol 45 (4) ◽  
pp. 195-202 ◽  
Author(s):  
John Bruce Cole ◽  
Marcos Vinicius Gualberto Barbosa da Silva

1995 ◽  
Vol 19 ◽  
pp. 1-7
Author(s):  
W. G. Hill ◽  
S. Brotherstone ◽  
P. M. Visscher

AbstractRates of genetic improvement in dairy cattle breeding programmes have increased substantially in the last decade, not only in Europe where there has been substantial immigration of North American stock. More accurate statistical evaluation procedures, including the use of best linear unbiased prediction (BLUP) with the animal model, have been introduced; higher selection intensities have been achieved, particularly on production traits, through better organized and focused schemes; and developments in multiple ovulation and embryo transfer (MOET) have been both a stimulus and to some extent a cause. Continued rapid improvement can be expected as research and development enables more accurate and timely use to be made of recording data, because there is evidence that heritability values for milk production are rising, perhaps because of better cow management, and as competition among breeders internationally increases. There are a number of consequent challenges to geneticists and breeders. Attention will have to be given to maintaining the fitness of very high producing animals by recording health, fertility, longevity and parlour traits, and using the results of research to give them appropriate weight in selection decisions. Developments in molecular methods and in reproductive technologies present new opportunities, but are unlikely to do more for some time than complement progress from conventional selection on the important production traits.


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