Breeding for Recoverability – a Novel Approach to Improve Genetics of Udder Health in Dairy Cows

PhD defence, Monday 20 November 2017, Berihu Gebremedhin Welderufael.

2017.11.20 | Trine Berndt Turtiainen Scheelke

Berihu Gebremedhin Welderufael

Historically, artificial selection has only focused on less susceptible cows to mastitis, leaving aside the other aspect of the disease - the recovery process. Using simulation studies, Berihu Gebremedhin Welderufael developed methods and models for a joint genetic and genomic evaluation of susceptibility to- and recoverability from mastitis. The methods are for the first time applied to real data collected from Danish dairy herds using milking robots. From the joint analyses, he estimated a correlation of -0.83 between the genetic effects influencing susceptibility to and recoverability from mastitis. His research showed that recoverability is as heritable as susceptibility and could be considered as a new trait for selection. Adding the genetics of recoverability in the genetic and genomic evaluation of disease data could be of specific benefit in situations of high disease prevalence.

This novel modeling approach enhances the genetic and genomic evaluation of mastitis by adding recovery information to the analysis.

The PhD degree was completed jointly at the Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences and at the Department of Molecular Biology and Genetics, Science and Technology, Aarhus University.

This résumé was prepared by the PhD student.

Time: Monday 20 November 2017 at 13.00
Place: Sal O1, Undervisningshuset, Ultuna, Uppsala, Sweden
Title of dissertation: Genetic evaluation of susceptibility to- and recoverability from mastitis in dairy cows
Contact information: Berihu Gebremedhin Welderufael, e-mail: berihu.welderufael@slu.se, tel.: +46 737365921
Members of the assessment committee:
Dr. Andrea Doeschl-Wilson,  The Roslin Institute & Royal (Dick) School of Veterinary Studies, University of Edinburgh
Professor Ulf Emanuelson, Department of Clinical Sciences, Swedish University of Agricultural Sciences
Dr. Bernt Gulbrandtsen, Department of Molecular Biology and Genetics, Aarhus University
Main supervisors:
Professor Dirk-Jan de Koning, Swedish University of Agricultural Sciences
Dr. Luc Janss, Aarhus University
Co-supervisors:
Dr. Peter Løvendahl, Aarhus University
Dr. Lars Peter Sørensen, SEGES, Denmark
Dr. Jessica Franzén, Department of Statistics, Stockholm University
Language: The PhD dissertation will be defended in English

The defence is public.
The dissertation is available for reading at the Graduate School of Science and Technology/GSST,
Ny Munkegade 120, building 1520, rooms 128-134, 8000 Aarhus C.

PhD defence
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Revised 23.11.2017