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Genetic variance and covariance components for across population evaluation of Brown Swiss cattle

Loberg, Anne (2015). Genetic variance and covariance components for across population evaluation of Brown Swiss cattle. Uppsala : Sveriges lantbruksuniv. , Rapport / SLU, Institutionen för husdjursgenetik, 1401-7520 ; 149
ISBN 978-91-576-9303-7
eISBN 978-91-576-9304-4
[Licentiate thesis]

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Abstract

Dairy cattle breeding is an international business, with trade of animal material across populations. Interbull performs international genetic evaluations of dairy bulls, enabling fair comparisons across populations. The bull daughter performances differ between populations and international evaluations therefore require estimation of genetic correlations between the populations. Prerequisites for estimating correlations are knowledge about the genetic variances and covariances within and between populations and the relationship between the bulls. Traditionally, pedigree information has been used to build the relationship matrix connecting included bulls. The recent developments in DNA technology have made it possible to also build genomic relationship matrices using information from the bull genomes.

The purpose of this thesis was to evaluate variances and covariances estimated using pedigree or genomic relationship matrices and the effect of factors such as trait heritability, population size, and number of bulls used in more than one population. Moreover, we evaluate the genetic correlations estimated using our different estimates.

Genetic variance estimates were compared for a total of 175 population-trait combinations, and genetic covariance and correlation estimates were assessed for four populations and three traits. Phenotypes, genotypes and pedigree were available for 8 864 Brown Swiss bulls originating from Germany-Austria, France, Italy, Slovenia, Switzerland and the United States of America.

The results showed that more genetic variance and covariance was explained when the pedigree relationship matrix was used than using the genomic relationship matrix. We found an effect of trait heritability and population size on the genetic variance estimates and an effect of number of common bulls on the genetic covariance estimates. The estimated genetic correlations were similar for both relationship matrices used in the estimation of variances and covariances, indicating that it should be possible to obtain accurate across-population correlation estimates using genomic relationship matrices.

Authors/Creators:Loberg, Anne
Title:Genetic variance and covariance components for across population evaluation of Brown Swiss cattle
Alternative abstract:
LanguageAbstract
SwedishUNSPECIFIED
Series/Journal:Rapport / SLU, Institutionen för husdjursgenetik (1401-7520)
Year of publishing :2015
Depositing date:21 May 2015
Volume:149
Number of Pages:40
Papers/manuscripts:
NumberReferences
ILoberg, A., Dürr, J.W., Fikse, W.F., Jorjani, H., and Crooks, L. (2015). Estimates of genetic variance and variance of predicted genetic merits using pedigree or genomic relationship matrices in six Brown Swiss cattle populations for different traits. Journal of Animal Breeding and Genetics, in press
IILoberg, A., Crooks, L., Fikse, W.F., Strandberg, E., and Jorjani, H. Estimation of genetic covariance across four Brown Swiss cattle populations using pedigree or genomic relationship matrices (manuscript)
Place of Publication:Uppsala
Publisher:Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-576-9303-7
ISBN for electronic version:978-91-576-9304-4
ISSN:1401-7520
Language:English
Publication Type:Licentiate thesis
Full Text Status:Public
Agris subject categories.:L Animal production > L10 Animal genetics and breeding
Subjects:(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 404 Agricultural Biotechnology > Genetics and Breeding
Agrovoc terms:dairy cattle, bulls, genetic variance, genetic covariance, genetic maps
Keywords:Brown Swiss cattle, genetic variance, genetic covariance, genomic relationship matrix, across population genetic correlation
URN:NBN:urn:nbn:se:slu:epsilon-e-2676
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-2676
ID Code:12257
Faculty:VH - Faculty of Veterinary Medicine and Animal Science
Department:(VH) > Dept. of Animal Breeding and Genetics
Deposited By: Anne Loberg
Deposited On:22 May 2015 13:39
Metadata Last Modified:01 Jun 2015 12:46

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