Dissemination of genetic progress: a key aspect of genetic improvement of local breeds

Author(s):  
Julie Labatut ◽  
Nathalie Girard ◽  
Jean-Miche Astruc ◽  
Bernard Bibé
1980 ◽  
Vol 60 (2) ◽  
pp. 253-264 ◽  
Author(s):  
A. J. McALLISTER

In the last decade the dairy cattle population has declined to a level of 1.9 million cows in 1978 with about 56% of these cows bred AI and nearly 20% of the population enrolled in a supervised milk recording program. The decline in cow numbers has been accompanied by an increase in herd size and production per cow. The current breeding program of the dairy industry is a composite of breeding decisions made by AI organizations, breeders who produce young bulls for sampling and all dairymen who choose the sires and dams of their replacement heifers. Estimates of genetic trend from 1958–1975 for milk production in the national milk recorded herd range from 21 to 55 kg per year for the four dairy breeds with Holsteins being 41 kg per year. Both differential use of superior proven sires and improved genetic merit of young bulls entering AI studs contribute to this genetic improvement. Various national production and marketing alternatives were examined. Selection is a major breeding tool in establishing a breeding program to meet national production requirements for milk and milk products once the selection goal is defined. AI and young sire sampling programs will continue to be the primary vehicle for genetic improvement through selection regardless of the selection goal. The current resources of milk-recorded cows bred AI is not being fully utilized to achieve maximum genetic progress possible from young sire sampling indicate that the number of young bulls sampled annually in the Holstein breed could be tripled with the existing milk-recorded and AI bred dairy cow population. Expanded milk recording and AI breeding levels could increase the potential for even further genetic improvement. The potential impact of selection for other traits, crossbreeding and the use of embryo transfer of future breeding programs is highlighted.


Author(s):  
J.G.E. Bryan ◽  
N.R. Wray ◽  
R. Crump ◽  
D.G. Nicholson ◽  
R. Thompson

The need to speed up the rate of genetic progress in beef cattle, particularly in economically significant traits such as growth and carcase merit has always been recognised by the Meat and Livestock Commission. This is achieved through the Beefbreeder Pedigree Recording Service which records over 1,000 pedigree herds in Great Britain. Traditionally, analysis of performance records from pedigree herds has been carried out using within herd contemporary comparisons.Average pedigree beef herd size in Great Britain is typically less than 20 cows which limits accuracy and scope for genetic improvement when making within herd selection decisions.


Author(s):  
J.P. Gibson

The goal of livestock genetic improvement is maximun increase in the economic efficiency of production (economic merit). When several traits contribute to economic merit, optimum genetic improvement can often be achieved by use of a discriminant function of available information (known as a selection index) which maximises expected genetic progress in the aggregate genotype, economic merit. This approach assumes that economic merit is a linear function of genetically controlled outputs. Although this may not always be true, since genetic responses are usually relatively small (0.005 to 0.020 of the mean per year) any non-linear effects are second-order and can generally be ignored. Economic optimization procedures which match production environments to genotypes would generate effectively non-linear functions, such non-linearity will generally be small. Thus the selection index approach can be applied, provided that functions describing economic merit are based on previously optimized production environments.


1978 ◽  
Vol 27 (2) ◽  
pp. 133-139 ◽  
Author(s):  
M. Soller

ABSTRACTThe use in dairy cattle improvement of loci associated with quantitative effects that might be found by genetic analysis is discussed. These methods can make a significant contribution only if they result in the identification of quantitative loci whose inheritance can be followed in a simple Mendelian manner. Another possibility, the identification of genetic components of production having a higher heritability than overall production, would make only a minor contribution to increased genetic progress. Selection of young males, according to the estimated breeding value associated by linkage with particular marker alleles in their sire, will not make a detectable contribution to genetic improvement.


2005 ◽  
Vol 45 (8) ◽  
pp. 1033 ◽  
Author(s):  
R. G. Banks

Investment in animal genetic improvement in Australia involves a diverse range of stakeholders and tackles complexity in a range of markets and production environments. While an excellent range of tools and knowledge for genetic improvement has been developed, industry-wide rates of genetic progress lag well below what is possible. This constitutes a considerable opportunity cost to the investors and to the wider community. It is proposed that this is partly a problem of coordination of effort across many diverse interests, and that this problem will be exacerbated by increasing availability, but complexity of use of genotypic information. Some approaches aimed at improving coordination and hence efficiency of investment are suggested, with consideration of the role of research and development corporations.


2003 ◽  
Vol 83 (3) ◽  
pp. 385-392 ◽  
Author(s):  
B. J. Van Doormaal ◽  
G. J. Kistemaker

Artificial insemination (AI) of dairy cattle in Canada was started more than half a century ago and today it is estimated that at least 75% of all dairy cattle nationally are bred using this common reproductive technology. A Best Linear Unbiased Prediction sire model for estimating genetic evaluations for production traits was introduced in 1975. The combination of extensive use of AI with genetic evaluations for bulls and cows has resulted in significant phenotypic and genetic gains over the past 20 yr. In the Holstein breed, mature equivalent yields have increased by an average of 200 kg milk, 7.0 kg fat and 6.3 kg protein per year since 1980. Genetically, the relative emphasis realized for production traits versus overall type during the past 5 yr has followed the 60:40 breeding goal represented in the Lifetime Profit Index, which has increased at an average rate of 0.28 standard units per year. Examination of the generation interval in the Canadian Holstein breed, associated with each of the four pathways for genetic improvement, indicates a 46% increase in the rate of annual genetic gain today compared to 20 yr ago. The increased accuracy and intensity of selection associated with the use of AI and genetic evaluations have also contributed to the rates of phenotypic and genetic progress achieved over the years. In the future , AI will continue to be a critical component of the genetic gains possible in dairy cattle breeding but it will be complemented by other reproductive technologies aimed at further reducing generation intervals and increasing the accuracy and selection of intensity, especially on the female side. Key words: Dairy cattle, artificial insemination, genetic progress, genetic evaluation


Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 535
Author(s):  
Ségolène Maucourt ◽  
Frédéric Fortin ◽  
Claude Robert ◽  
Pierre Giovenazzo

Genetic improvement programs have resulted in spectacular productivity gains for most animal species in recent years. The introduction of quantitative genetics and the use of statistical models have played a fundamental role in achieving these advances. For the honeybee (Apis mellifera), genetic improvement programs are still rare worldwide. Indeed, genetic and reproductive characteristics are more complex in honeybees than in other animal species, which presents additional challenges for access genetic selection. In recent years, advances in informatics have allowed statistical modelling of the honeybee, notably with the BLUP-animal model, and access to genetic selection for this species is possible now. The aim of this project was to present the genetic progress of several traits of interest to the Canadian beekeeping industry (hygienic behavior, honey production and spring development) achieved in our selection program since 2010. Our results show an improvement of 0.30% per year for hygienic behavior, 0.63 kg per year for honey production and 164 brood cells per year for spring development. These advances have opened a new era for our breeding program and sharing this superior genetic available to beekeepers will contribute to the sustainability and self-sufficiency of the beekeeping industry in Canada.


2018 ◽  
Vol 51 ◽  
pp. 27-34 ◽  
Author(s):  
O. I. Babenko ◽  
V. P. Оleshko ◽  
V. Y. Afanasenko

Genetic progress in a herd of animals is due to the selection of four categories of pedigree animals: fathers of sires, mothers of sires, fathers of cows and mothers of cows. Extremely important role in genetic improvement of a herd plays selection of the sires for insemination of breeding stock which become the potential parents of cows. The selection of sires’ mothers, sires’ and cows’ parents provides 90-95% of the effect of selection in animal population, and massive selection of cows’ mothers only 5-10%. The main selection trait in а herd is milk production, therefore with the purpose of analyzing the effectiveness of selection by this trait defined pedigree value of 4 categories of pedigree animals, which influenced on the pace of improvement of the populations. Therefore, to accelerate genetic improvement of dairy cattle populations is necessary to increase the magnitude of the genetic benefits of parental animals and reduced generation intervals, which is the aim of our research. The average annual genetic progress through selection of four categories of pedigree animals in the herd of Holstein breed is 61.2 kg of milk per cow per year and the pace of genetic improvement of the herd – 0.81 %. In the population of Ukrainian Black-and-White Dairy breed, these figures are respectively 43.2 kg of milk and the pace of genetic improvement of the herd – 0.62 % Much more opportunities in raising the rate of genetic improvement can be achieved through the introduction of genomic (GS) or marker-assisted selection (MAS). Under the terms of the genomic breeding, final estimation of pedigree value of sires is carried out during 2.5 years in the contrast with traditional breeding, which involves the time for 5 years. Experts estimate the cost from the use of GS or MAS compared with conventional breeding are up to 92%, and the efficiency of selection is improved two times. Taking into account that data of productivity of animals are associated with genes of economically useful traits, the topical issue is the selection of the optimal polymorphic marker systems for their introduction into practice of breeding and assessment of genetic structure of cattle breeds. On the basis of our results of studies of the effect of QTL – gene, the complex model genotype for the selection of animals for the purpose of increasing milk yield in animals of Ukrainian Black-and-White Dairy breed is like this: CSNSАВ, GHLL, βLGАВ, Pit-1АВ; Holstein – CSNS AB, GHLV, βLGАA, Pit-1АВ. Comparison of model genotypes of Ukrainian Black-and-White Dairy and Holstein shows that there are differences in the combination of genotypes contributing to the best development of traits. Thus, the mass fraction of the protein, the model genotypes are identical at 75% in both breeds: by the yield, quantity of milk fat and protein and total milk fat and protein model genotypes match by 50%. Due to implementation of genomic evaluation and breeding of dairy cattle, the valuation period of pedigree animals was reduced significantly. Unlike conventional breeding, the introduction of genomic selection will reduce the genetic interval in the population of Ukrainian Black-and-White Dairy breed of sires’ fathers by 4.5 years, sires’ mothers by 4.6 years, cows’ fathers by 4.6 years and cows’ mothers by 2.9 years. In the population of Holstein cattle generation interval of sires’ fathers is reduced by 4.3 years, sires’ mothers by 4.5 years, cows’ fathers by 4.5 years, and cows’ mothers by 2.7 years. The results of our studies show that the rate of genetic improvement of dairy cattle population in the main breeding traits can be improved through the selection of animals by QTL-complexes. Thus, the selection of breeding stock based on a comprehensive model of genotype on yield gave an opportunity to improve pedigree value of the maternal cows at 155 kg compared to traditional breeding, and in the population of Holstein cattle at 246 kg. Only these factors allow genetic progress in milk yield in the population of Ukrainian Black-and-White Dairy cattle by 128.5 kg, which is 2.9 times more than the value of the actual genetic progress and in the population of Holstein cattle – 183.2 kg, which is three times more compared to the actual value of genetic progress for milk yield in this population. The contribution of the cows’ mothers to genetic progress increases. So, if at conventional breeding, the contribution of this category of pedigree animals was negative (-4.9%), selection on QTL complex is 3.2% and in the population of Holstein cattle 12%. If you apply the selection of other categories of pedigree animals (sires’ fathers, mothers and parents of sires) on QTL-complexes, which contribution in the genetic improvement of populations is 88.0–96.8%, the rate of genetic improvement of dairy cattle populations will greatly increase. Conclusion. To accelerate genetic improvement of dairy cattle populations it is necessary to use molecular genetic markers that control metabolic processes in the body.


2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Almoataz Bellah Ali El-Mouhamady ◽  
Magdy Ahmad Al-Kordy ◽  
Tarik Abdel-Fatah Elewa

Abstract Background Sugar beet is considered a very important strategic economic crop, as it comes at the second place for white sugar production in Egypt after sugar cane and the sugar percentage in its roots is 20%. This work was conducted in Egypt as a direct response to bridge the gap which began to expand significantly between the production and consumption of white sugar and the desire for the genetic improvement process to increase the productivity of this crop. Further, as serious attempt to understand the nature of the genetic diversity among a group of sugar beet accessions with different origins, it constitutes an important source for establishing a program of breeding and improving sugar beet crop under Egyptian conditions. Results The process of verifying the existence of significant genetic variation between the eight sugar beet varieties with various origins was carried out through a set of genetic parameters through two growing seasons besides, the data of ISSR markers profile. Further, all the sugar beet varieties were superior in all the studied traits during their evaluation over two agricultural years, where the two sugar beet accessions Oscar Poly and Rass Poly are superior in TSS % and sucrose % traits, Mont Bianco and Sultan in apparent purity % trait, Blino and Sultan in root yield and top yield traits and Rass Poly and Blino in sugar yield trait, respectively. In addition, the values of heritability in broad sense were high in all studied traits except the two traits; sucrose % and sugar yield where their results were appeared medium during both growing seasons. In the same regard, expected genetic advance values showed significant genetic progress in all studied traits during the two growing seasons. As well, highly genetic diversity was obtained between the eight sugar beet accessions through generated 169 amplified fragments from the twelve ISSR primers, 122 of them were polymorphic with 72.18% polymorphism. Conclusions The eight sugar beet varieties achieved remarkable and distinctive results for all traits under study during two agricultural years. However, they were differentiated and various from each other. As they differed in their superiority in all estimated traits and they proved to be fertile material for studying in this investigation and very suitable for enriching the breeding and genetic improvement program to promote the sugar beet yield in order to increase the productivity of white sugar in Egypt.


2020 ◽  
Vol 43 ◽  
pp. e45767
Author(s):  
Antônio Carlos da Silva Junior ◽  
Vinicius Quintão Carneiro ◽  
Iara Gonçalves dos Santos ◽  
Renato Domiciano Silva Rosado ◽  
Cosme Damião Cruz ◽  
...  

The importance of rice (Oryza sativa) is indisputable this cereal is the staple food for half of the global population. Genetic progress estimation allows evaluation of the effectiveness of genetic improvement of crops and helps in the planning of breeding programs. This paper aims to estimate the genetic yield progress made by the program in the state of Minas Gerais, Brazil, which is run by the Epamig/UFV/Embrapa consortium. A total of 210 lines were evaluated by value for cultivation and use testing that was conducted in the municipalities of Janaúba, Leopoldina, and Lambari, from 1993 to 2016. Based on Vencovsky’s (1986) method, the genetic gains in Lambari, Janaúba, and Leopoldina were 1.46, 0.14, and 0.11%, respectively. The gain in Leopoldina was considered very low during the evaluated period. According to Breseghello’s (1998) method, the annual average genetic gain was 0.23 and 0.04% in Lambari and Janaúba, respectively. In Leopoldina, a yield gain of - 2.37% per year was observed for the evaluation period from 1994 to 1999, and a yield gain of 0.1% per year was observed from 2000 to 2016. These results can be explained by the focus on quality as a strategy for the breeding program in Minas Gerais State in the 1990s. Vencovsky’s (1986) and Breseghello’s (1998) methods were able to quantify yield gains and demonstrate the dynamics of the irrigated rice genetic improvement program in Minas Gerais State.


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