During his PhD studies, Rasmus Bak Stephansen researched on the quantitative genetic aspects of feed efficiency in dairy cattle, and developed novel statistical models that dairy breeders world-wide potentially can adopt to improve their environmental and economic sustainability. Rasmus Bak Stephansen studied how new statistical models, developed on a unique worldwide research dataset and validated on data from a state-of-the-art 3D camera-based system, can improve individual dairy cow feed efficiency through genetics, without compromising dairy cow productivity and animal welfare.

The new research findings contribute to the quantitative genetic understanding of feed efficiency, showing that feed efficiency changes genetically within and across lactations, highlighting the importance of full productive lifetime recording. Furthermore, the research showed how feed efficiency could be improved without compromising productivity and animal welfare, and potentially be a climate gas mitigation path to explore.

The PhD study was completed at Center for Quantitative Genetics and Genomics (QGG), Faculty of Technical Sciences, Aarhus University.

This summary was prepared by the PhD student.

Time: Monday, 4 November 2024 at 12:00
Place: Building 1632, room 201, AIAS, Aarhus University, Høegh-Guldbergs Gade 6B, 8000 Aarhus C, Denmark
Title of PhD thesis: Genetic Improvement of Feed Efficiency in Dairy Cattle
Contact information: Rasmus Bak Stephansen, e-mail: rasmus.stephansen@qgg.au.dk, tel.: +45 6176 4959

Members of the assessment committee:
Professor Guilherme J. M. Rosa, Animal & Dairy Sciences, University of Wisconsin Madison, USA

Professor Bjorg Heringstad, Animal Breeding and Aquacultural Sciences, NMBU, Norway

Professor Doug Speed (chair), QGG, Aarhus University, Denmark

Main supervisor:
Senior Scientist Goutam Sahana, QGG, Aarhus University, Denmark

Co-supervisor:
Project Senior Scientist Jan Lassen, Research Development, VikingGenetics, Denmark

Researcher Coralia Ines Valentina Manzanilla-Pech, Animal Breeding & Genomics, Wageningen University & Research, the Netherlands

Language: The PhD dissertation will be defended in English

The defence is public.
The PhD thesis is available for reading at the Graduate School of Technical Sciences/GSTS, Ny Munkegade 120, building 1521, 8000 Aarhus C.