Structure of the holstein dairy cattle subpopulation in Russia by locus CSN2 and CSN3

Author(s):  
N. Kovalyuk ◽  
N. Altukhova ◽  
M. Glushchenko ◽  
A. Solovykh

Purpose: to determine the potential of the Russian subpopulation of the Holstein breed in relation to selection by loci of beta-and kappa-casein.Materials and methods. For loci CSN2 and CSN3, 1,539 Holstein cattle were genotyped, including 1,242 cows and heifers and 297 sires, and information on CSN2 and CSN3 genotypes of 297 US bulls was analyzed (World Wide Sires, Ltd).Results. It has been established that in the last two years there has been an increase in the percentage of sires in WWS with CSN2 genotypes A2A2 and CSN3 genotypes BB. Thus, sires allele frequency in the 2019 catalog was 0.51 and 0.29, respectively; and in the 2021 catalog was 0.68 and 0.31, respectively.Genotyped sires of domestic breeding organizations, which are mostly foreign origin, were characterized by predominance of the A2 allele CSN2; in this group the frequency of the allele was 0.63. However, the CSN3 B allele in the group of sires belonging to domestic organizations was found with a frequency of 0.34, which is 1.6 times lower than that of sires of American origin.In the genotyped group of Holstein cows and heifers (n = 1242) belonging to 3 large farms in the Krasnodar Krai, the gene frequency CSN2 allele A2 was minimal (0.57), and the CSN3 allele B (0.40) was higher than the allele frequency in the sires group of domestic breeding enterprises.Conclusion. At present, Russian breeding enterprises and farms are lagging behind in these indicators, however, by conducting targeted selection in accordance with the indicated trend, by selecting the appropriate breeding bulls, it is possible in the next generation to increase the proportion of animals carrying valuable genotypes.

2019 ◽  
pp. 9-11
Author(s):  
N.B. KOVALYUK ◽  
V.F. SATSOUK ◽  
E.V. MACHULSKAYA ◽  
L.I. JAKUSHEVA ◽  
A.A. KASEM

С целью оценки возможности отечественных и зарубежных племенных предприятий для ведения селекции на повышение сыропригодности и безопасности молока проведено генотипирование по локусу CSN2 (бетаказеина) 308 быковпроизводителей голштинской и айрширской пород. Учтена информация о CSN2 генотипах 390 быковпроизводителей. По локусу CSN3 (каппаказеина) генотипировано 73 производителя айрширской и голштинской пород, учтена информация о CSN3 генотипах 615 быковпроизводителей. Установлено, что быкипроизводители голштинской породы не имеют существенных отличий в частоте встречаемости желательного CSN2 генотипа А2А2 (3642) быки голштинской породы отечественных племенных предприятий в 24 раза уступают по распространенности желательного CSN3 генотипа ВВ (частота встречаемости составляет 713) производителям компании World Wide Sires (28) быкипроизводители айрширской породы отечественных племенных предприятий в 23 раза уступают быкам компании VikingGenetics по распространенности желательных CSN2 и CSN3 генотипов. Считаем, что отечественным племенным предприятиям с целью повышения конкурентоспособности необходимо увеличить долю быков с генотипами А2А2 (локус CSN2), АВ и ВВ (локус CSN3).In order to assess the possibility of domestic and foreign breeding enterprises for breeding to improve the cheese suitability and safety of milk, genotyping of 308 Holstein and Ayrshire bulls by CSN2 (betacasein) locus was carried out. Information on CSN2 genotypes of 390 bulls was taken into account. 73 producers of Ayrshire and Holstein breeds were genotyped by CSN3 locus (kappacasein), information on CSN3 genotypes of 615 bulls was taken into account. Found that bulls of Holstein breed are not significant differences in the frequency of occurrence of desirable CSN2 genotype А2А2 (3642) bulls Holstein breeding enterprises in 24 times inferior to the prevalence of desirable genotype CSN3 the BB (the frequency of occurrence is 713) manufacturers company World Wide Sires (28) bulls Ayrshire breed of domestic breeding enterprises is 23 times the yield of the company VikingGenetics bulls on the prevalence of desirable CSN2 and CSN3 genotypes. We believe that domestic breeding enterprises in order to increase competitiveness need to increase the proportion of bulls with genotypes A2A2 (locus CSN2), AB and BB (locus CSN3).


2021 ◽  
Author(s):  
Michael Schneider ◽  
Asis Shrestha ◽  
Agim Ballvora ◽  
Jens Leon

Abstract BackgroundThe identification of environmentally specific alleles and the observation of evolutional processes is a goal of conservation genomics. By generational changes of allele frequencies in populations, questions regarding effective population size, gene flow, drift, and selection can be addressed. The observation of such effects often is a trade-off of costs and resolution, when a decent sample of genotypes should be genotyped for many loci. Pool genotyping approaches can derive a high resolution and precision in allele frequency estimation, when high coverage sequencing is utilized. Still, pool high coverage pool sequencing of big genomes comes along with high costs.ResultsHere we present a reliable method to estimate a barley population’s allele frequency at low coverage sequencing. Three hundred genotypes were sampled from a barley backcross population to estimate the entire population’s allele frequency. The allele frequency estimation accuracy and yield were compared for three next generation sequencing methods. To reveal accurate allele frequency estimates on a low coverage sequencing level, a haplotyping approach was performed. Low coverage allele frequency of positional connected single polymorphisms were aggregated to a single haplotype allele frequency, resulting in two to 271 times higher depth and increased precision. We compared different haplotyping tactics, showing that gene and chip marker-based haplotypes perform on par or better than simple contig haplotype windows. The comparison of multiple pool samples and the referencing against an individual sequencing approach revealed whole genome pool resequencing having the highest correlation to individual genotyping (up to 0.97), while transcriptomics and genotyping by sequencing indicated higher error rates and lower correlations.ConclusionUsing the proposed method allows to identify the allele frequency of populations with high accuracy at low cost. This is particularly interesting for conservation genomics in species with big genomes, like barley or wheat. Whole genome low coverage resequencing at 10x coverage can deliver a highly accurate estimation of the allele frequency, when a loci-based haplotyping approach is applied. Using annotated haplotypes allows to capitalize from biological background and statistical robustness.


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):  
O. V. Gorelik ◽  
N. A. Fedoseeva ◽  
A. S. Gorelik ◽  
E. V. Koksharov

In the last few decades the improvement of domestic dairy cattle was due to the widespread use of the gene pool of the best world breed such as Holstein. As a result of crossbreeding the breeding stock of the domestic Black-and-White breed with the sires of Holstein breed in different regions of the country a population of crossbreds has been created. The purpose of the work was to study the age dynamics of the live weight of replacement heifers depending on the paternal origin and the correlation between the indicators for the growth periods. The daughters of different sires have a difference in their live weight at the first insemination. The live weight of more than 400 kg was obtained from replacement heifers obtained from the sires Saber, Decaro and Baquero. The daughters of the sires Gatedenser, Bentley and Alta Ciara in live weight were inferior to their herdmates by 2,7–9,3 kg or by 0,7–2,8 % (P ≥ 0,05). The bulk of the replacement heifers are inseminated at the age of 13 months and only the daughters of the sire Alta Ciara are inseminated at the age of 14,1 months with a live weight of 396,7 kg. Despite the almost identical live weight of heifers at birth they differed from each other in the process of rearing. It has been established that the live weight at birth is not an indicator for assessing the further growth of replacement young animals. At 6 months of age the correlation of live weight at the age of 6 months and at the first insemination was positive and ranges from 0,01 (daughters of the sire Baquero) to 0,55 (daughters of the sire Decaro). Selection of heifers at the age of 6 months by their live weight allows us to choose the best and provide the opportunity to inseminate them at the age of 12–13 months with the organization of intensive rearing.


2011 ◽  
pp. 89-100
Author(s):  
Ali Jafari

Today’s portals bring together existing technologies in useful, innovative ways, but they don’t scratch the surface of what is possible. The constant build-up of information and resources on the World Wide Web demands a smarter more advanced portal technology that offers dynamic, personalized, customized, and intelligent services. This chapter discusses next-generation portals and the requirement that they come to know their users and understand their individual interests and preferences. It describes a new generation of portals that have a level of autonomy, making informed, logical decisions and performing useful tasks on behalf of their members. The chapter highlights the role of artificial intelligence in framing the next generation of portal technology and in developing their capabilities for learning about their users.


2017 ◽  
Vol 62 (No. 4) ◽  
pp. 157-167
Author(s):  
N. Chen ◽  
F. Wang ◽  
N. Yu ◽  
Y. Gao ◽  
J. Huang ◽  
...  

The primary agent of mastitis is a wide spectrum of bacterial strains; however, viral-related mastitis has also been reported. The MX dynamin-like GTPase 1 (MX1) gene has been demonstrated to confer positive antiviral responses to many viruses, and may be a suitable candidate gene for the study of disease resistance in dairy cattle. The present study was conducted to investigate the genetic diversity of the MX1 gene in Chinese cattle breeds and its effects on mastitis in Holstein cows. First, polymorphisms were identified in the complete coding region of the bovine MX1 gene in 14 Chinese cattle breeds. An association study was then carried out, utilizing polymorphisms detected in Holstein cows to determine the associations of these single nucleotide polymorphisms (SNPs) with mastitis. We identified 13 previously reported SNPs in Chinese domestic cattle and four of them in Holstein cattle. A novel 12 bp indel was also discovered in Holstein cattle. In addition, haplotype frequencies and linkage disequilibrium of four SNPs detected in Holstein cows were investigated. Analysis of these four SNPs in Chinese Holstein cows revealed two SNPs (g.143181370 T&gt;C and g.143182088 C&gt;T)<br /> significantly (P &lt; 0.05) associated with somatic cell score (SCS). The results indicated that SNPs in the MX1 gene might contribute to the variations observed in the SCS of dairy cattle. Therefore, implementation of these two mutations in selection indexes of the dairy industry might be beneficial by favouring the selection individuals with lower SCS.


2020 ◽  
Vol 100 (1) ◽  
pp. 175-183
Author(s):  
Bernard Ato Hagan ◽  
Roger Cue

Genetic evaluation records for the Canadian Holstein, Ayrshire, Jersey, and Brown Swiss bulls and cows born from 1950 and 1960, respectively, were used to study the generation intervals (L) along the four-path selection model. The objectives of the study were to determine the L in the four dairy cattle breeds and the effects of some environmental factors and variations among herds or artificial insemination (AI) studs on the L achieved. Total L of the four selection paths was reduced by 55% from 29.2 yr in 1980 to 13.2 yr in 2016 in the Holstein breed. Substantial reductions in total L were also observed in the Ayrshire, Jersey, and Brown Swiss populations between 1980 and 2016. Unlike progeny year of birth, housing system, agricultural region in Québec (region) — as well as their interaction — were not important on realised L of sires and dams used on Canadian dairy farms. There were significant variations among herds and AI studs on the age of sires and dams used for breeding. The considerable variations in realised L among herds and AI studs offer opportunities to increase the annual rate of genetic progress in the four Canadian dairy cattle populations.


2004 ◽  
Vol 55 (8) ◽  
pp. 825 ◽  
Author(s):  
B. J. Wood ◽  
J. H. J. van der Werf ◽  
P. F. Parnell

This paper quantifies the benefits of using a sire genotyped for a single recessive gene in a commercial beef herd. A modified gene-flow method was used to account for changing allele frequency over time. The benefits to a commercial breeder of using a genotyped sire were highest when initial allele frequency was moderate and when the sire was used in a self-replacing herd that had increased allele frequency over time. An example of the thyroglobulin gene affecting marbling in beef cattle was used. The value to a self-replacing herd of a sire homozygous for the favourable allele of the thyroglobulin gene was shown to be up to $338 more than of an ungenotyped sire, in a population where the initial gene frequency was 0.3 and the genotype accounted for 0.5 standard deviations of phenotypic variation.


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