The blue line is a linear regression line with slope 3. Thus the genetic architecture of the UC DYD is characterized by a large number of genes with small effects and only few genes with major effects, as it is typical for many complex quantitative traits . First mapping results in cattle seem to validate the classical quantitative genetic model of a large number of loci of small additive effects ,, and agree with findings from mapping QTL in the human genome . Calving ease is a major breeding objective in cattle populations as calving difficulties dystocia are often accompanied with calf losses and thus substantially compromise animal and economical welfare. Natural Selection or Social Preference?
European Journal of Pediatrics QTL mapping experiments in cattle populations were successfully performed using progeny-derived phenotypes for artificial insemination bulls which were genotyped for a small number of polymorphic microsatellites i. This dual purpose selection is likely to act on the two QTL identified in our study. Using progeny-derived phenotypes for genome-wide association analyses Phenotypes for most economically important traits are recorded in female animals in cattle breeding programs. Journal of Cutaneous Medicine and Surgery:
The correlation of pCE with growth-related traits and the coincident QTL point to fetal growth and the resulting birth weight as major determinant for the ease of delivery ,. A similar mechanism is plausible for eye-area pigmentation in cattle.
The successful elimination of false positive association signals is evidenced by a genomic inflation factor of 1. The black line is a linear regression line through these points, whereas the black dotted line represents the population mean.
Detailed view of the region on chromosome 14 delineated by the haplotype associated with the estimated breeding value EBV for paternal calving ease pCE.
Mrode RA, Swanson GJT Calculating cow and daughter yield deviations and partitioning of genetic evaluations under a random regression model. Re- sequencing a small number of key animals enables to assess a large fraction of the global genomic variation of livestock populations ,.
Breeds with white heads, e. Homepage Navigation Content Sitemap Search. Similar conclusions are drawn in studies considering genomic selection where improving the accuracy of genomic predictions is the most important issue.
American Journal of Physical Anthropology Access to large independent validation populations  and comprehensive functional investigations , respectively, is indispensable for the fine-mapping of QTL regions in livestock populations. The medium-density and the high-density SNP map account for The availability of the bovine reference sequence allowed dissertqtion for the systematic assessment of a large number of single nucleotide polymorphisms SNPs by whole genome re-sequencing of paucsh animals ,,,.
Qianqian Zhang: Towards Cattle Precision Breeding Using Next Generation Sequencing
On the other hand it seems likely that the QTL accounts for a small fraction of the genetic variation only, requiring larger sample sizes for its detection. Thus, the two QTL might primarily affect fetal growth.
Pigmentation around the eyes is highly correlated with eye-lid and corneoscleral pigmentation . The genetic value of male animals can be obtained for these traits via breeding value estimation . Of the eight significant SNPs on chromosome 14, six lie within a 1.
Our study demonstrates the leverage potential of EBVs in unravelling the genetic architecture of lowly heritable traits. A major fraction of the phenotypic variation is attributable to BTA5 There is also support in the literature for suggestive QTL on other chromosomes: Since marker alleles with negative effect on pCE have positive effects on growth-related traits, the QTL may exert their effects on the birthing process through fetal growth traits. The blue line is a linear regression line.
The four QTL explain a substantial fraction of the genetic variation of supernumerary teats. B Heatmap of the coefficients of relationship presents cluster of related individuals.
(PDF) Genome-wide analysis of complex traits in cattle | Hubert Pausch –
Improving postnatal growth along with lactation traits is a major breeding objective of the FV breed. Journal of Anatomy Identification of functional genes within the associated regions The gene content of the associated regions was analysed based on the University of Maryland UMD3.
SNTs may be positioned at the rear udder caudalbetween the normal front and rear teats intercalary or as appendix of normal teats ramal. The chromosomes harbouring significantly associated SNPs account for Animals showing major discrepancies of the pedigree and genomic relationship were omitted. Natural Selection or Social Preference? Genetics in Agricultural Sciences.
Journal of Animal Breeding and Genetics