Joergen Kjaer

Dr. Joergen Kjaer


Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications

1 February 2009 in Physiology & Behavior
Verified
Journal Article
Closed access
JKJoergen Kjaer
Joergen Kjaer
DGDaniel Guémené
Daniel Guémené

1 August 2018 in Applied Animal Behaviour Science
Verified
Journal Article
Open access
JEJerine A.J. van der Eijk
Jerine A.J. van der Eijk
A (Aart) LammersA (Aart) Lammers
A (Aart) Lammers
PLPeiyun Li
Peiyun Li
JKJoergen Kjaer
Joergen Kjaer
TRT. Bas Rodenburg
T. Bas Rodenburg

12 July 2011 in Genes, Brain and Behavior
Verified
Journal Article
Closed access
PDF file
JKJoergen Kjaer
Joergen Kjaer
HJH. Jørgensen
H. Jørgensen

1 July 2014 in Behavioural Brain Research
Verified
Journal Article
Closed access
MKMarjolein S. Kops
Marjolein S. Kops
JKJoergen Kjaer
Joergen Kjaer
OGOnur Güntürkün
Onur Güntürkün
KWKoen G.C. Westphal
Koen G.C. Westphal
GKGerdien A.H. Korte-Bouws
Gerdien A.H. Korte-Bouws
KSKorte S.M.
Korte S.M.

30 September 2015 in Genetics Selection Evolution
Verified
Journal Article
Open access
PDF file
VGVanessa Grams
Vanessa Grams
RWRobin Wellmann
Robin Wellmann
SPSiegfried Preuß
Siegfried Preuß
MGMichael A. Grashorn
Michael A. Grashorn
JKJoergen Kjaer
Joergen Kjaer
JBJörn Bennewitz
Jörn Bennewitz
Feather pecking (FP) in laying hens is a well-known and multi-factorial behaviour with a genetic background. In a selection experiment, two lines were developed for 11 generations for high (HFP) and low (LFP) feather pecking, respectively. Starting with the second generation of selection, there was a constant difference in mean number of FP bouts between both lines. We used the data from this experiment to perform a quantitative genetic analysis and to map selection signatures. Pedigree and phenotypic data were available for the last six generations of both lines. Univariate quantitative genetic analyses were conducted using mixed linear and generalized mixed linear models assuming a Poisson distribution. Selection signatures were mapped using 33,228 single nucleotide polymorphisms (SNPs) genotyped on 41 HFP and 34 LFP individuals of generation 11. For each SNP, we estimated Wright’s fixation index (FST). We tested the null hypothesis that FST is driven purely by genetic drift against the alternative hypothesis that it is driven by genetic drift and selection. The mixed linear model failed to analyze the LFP data because of the large number of 0s in the observation vector. The Poisson model fitted the data well and revealed a small but continuous genetic trend in both lines. Most of the 17 genome-wide significant SNPs were located on chromosomes 3 and 4. Thirteen clusters with at least two significant SNPs within an interval of 3 Mb maximum were identified. Two clusters were mapped on chromosomes 3, 4, 8 and 19. Of the 17 genome-wide significant SNPs, 12 were located within the identified clusters. This indicates a non-random distribution of significant SNPs and points to the presence of selection sweeps. Data on FP should be analysed using generalised linear mixed models assuming a Poisson distribution, especially if the number of FP bouts is small and the distribution is heavily peaked at 0. The FST-based approach was suitable to map selection signatures that need to be confirmed by linkage or association mapping.