Distribution and location of genetic effects for dairy traits
TL;DR: A high-density scan using 38,416 single nucleotide polymorphism markers for 5,285 bulls confirmed 2 previously known major genes on Bos taurus autosomes (BTA) 6 and 14 but revealed few other large effects as discussed by the authors.
About: This article is published in Journal of Dairy Science.The article was published on 2009-06-01 and is currently open access. It has received 224 citations till now. The article focuses on the topics: Quantitative trait locus & Allele.
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TL;DR: This review aims to point out some of the tools that may help to determine genome and epigenome associations, thus creating a new perspective for animal breeding by allowing the selection of desired genotypes and epigenotypes.
8 citations
TL;DR: Differences in least squares means of direct genomic values (DGV) for paternal and maternal haplotypes of Bos taurus autosomes 1, 6, 14, and 18 for lifetime net merit were significant in all but one case.
8 citations
01 Jan 2011
TL;DR: It is recommended to restrict the use of sires with a higher incidence of dystocia or stillbirth in the offspring, as genetically determined variability is very low and other systematic measures are necessary to control stillbirth and dystOCia.
Abstract: Out of 5970 calvings, 4.29% had an abnormal course (dystocia). The occurrence of stillbirths was 6.98% of all births and 4.15% of normal course births. Stillbirths occurred in 70.31% of dystocias. The highest frequency of stillbirths was in Blonde d Aquitaine (8.59%) and the lowest in Gasconne (3.96%) cows. A narrow pelvis and an oversized foetus were the causes of more than 50% cases of dystocia. In Charolaise, an extremely high occurrence of oversized foetus, while in Blonde d Aquitaine uterine inertia were found. A narrow pelvis was especially frequent as the cause of dystocia in the Aberdeen Angus and Limousine breeds. On analysis of stillbirths the most important effect was of the calving course with 24.47% impact on variability. Difficult calving increased the odds of stillbirth by 76 compared to normal calving. The heritability of stillbirth was estimated as 7.80%. It is recommended to restrict the use of sires with a higher incidence of dystocia or stillbirth in the offspring. As genetically determined variability is very low, other systematic measures are necessary to control stillbirth and dystocia. These are: supervision of the herd, obstetrical assistance, appropriate heifer rearing, mating cows at the proper live weight and proper nutrition during the pregnancy.
8 citations
12 Feb 2011
TL;DR: This paper presents a meta-analysis of model parameters and test statistics for multiple-QTL analysis using linkage disequilibrium and linkage analysis (LDLA) method to derive values for SNP selection and genotyping parameters.
Abstract: 52 Background 54 Materials and Methods 56 Animals and phenotypes 56 DNA preparation and microsatellite marker selection and genotyping...... 56 SNP selection, genotyping and haplotyping 57 Linkage map construction 58 QTL fine mapping 59 Multiple-QTL analysis using linkage disequilibrium and linkage analysis (LDLA) method 60 Estimation of model parameters and test statistics 61
8 citations
TL;DR: P phenotypic characterization of digital cushion thickness (DCT) to the Jersey breed and include mature bulls and to identify breed-specific quantitative trait loci (QTL) for DCT within the Jersey or Holstein breeds and common QTL across breeds and sexes to better understand biological regulation and guide future use of marker-assisted selection.
7 citations
References
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Book•
01 Jan 1981
TL;DR: The genetic constitution of a population: Hardy-Weinberg equilibrium and changes in gene frequency: migration mutation, changes of variance, and heritability are studied.
Abstract: Part 1 Genetic constitution of a population: Hardy-Weinberg equilibrium. Part 2 Changes in gene frequency: migration mutation. Part 3 Small populations - changes in gene frequency under simplified conditions. Part 4 Small populations - less simplified conditions. Part 5 Small populations - pedigreed populations and close inbreeding. Part 6 Continuous variation. Part 7 Values and means. Part 8 Variance. Part 9 Resemblance between relatives. Part 10 Heritability. Part 11 Selection - the response and its prediction. Part 12 Selection - the results of experiments. Part 13 Selection - information from relatives. Part 14 Inbreeding and crossbreeding - changes of mean value. Part 15 Inbreeding and crossbreeding - changes of variance. Part 16 Inbreeding and crossbreeding - applications. Part 17 Scale. Part 18 Threshold characters. Part 19 Correlated characters. Part 20 Metric characters under natural selection.
20,288 citations
TL;DR: It was concluded that selection on genetic values predicted from markers could substantially increase the rate of genetic gain in animals and plants, especially if combined with reproductive techniques to shorten the generation interval.
Abstract: Recent advances in molecular genetic techniques will make dense marker maps available and genotyping many individuals for these markers feasible. Here we attempted to estimate the effects of ∼50,000 marker haplotypes simultaneously from a limited number of phenotypic records. A genome of 1000 cM was simulated with a marker spacing of 1 cM. The markers surrounding every 1-cM region were combined into marker haplotypes. Due to finite population size (Ne = 100), the marker haplotypes were in linkage disequilibrium with the QTL located between the markers. Using least squares, all haplotype effects could not be estimated simultaneously. When only the biggest effects were included, they were overestimated and the accuracy of predicting genetic values of the offspring of the recorded animals was only 0.32. Best linear unbiased prediction of haplotype effects assumed equal variances associated to each 1-cM chromosomal segment, which yielded an accuracy of 0.73, although this assumption was far from true. Bayesian methods that assumed a prior distribution of the variance associated with each chromosome segment increased this accuracy to 0.85, even when the prior was not correct. It was concluded that selection on genetic values predicted from markers could substantially increase the rate of genetic gain in animals and plants, especially if combined with reproductive techniques to shorten the generation interval.
6,036 citations
TL;DR: Efficient methods for processing genomic data were developed to increase reliability of estimated breeding values and to estimate thousands of marker effects simultaneously, and a blend of first- and second-order Jacobi iteration using 2 separate relaxation factors converged well for allele frequencies and effects.
4,196 citations
TL;DR: Genotypes for 38,416 markers and August 2003 genetic evaluations for 3,576 Holstein bulls born before 1999 were used to predict January 2008 daughter deviations and genomic prediction improves reliability by tracing the inheritance of genes even with small effects.
1,166 citations