Project code: 28RZ372013
Contract period: 01.07.2015
Budget: 146,464 Euro
Purpose of research: Applied research
The overall aim of the project is to provide biomarker for selecting individuals with superior immune competence for improved cattle breeding. To this end, an interdisciplinary collaboration of experts in dairy cattle medicine, immunology, molecular biology and genetics and molecular microbiology is established. This team will discover the genetic and immunophysiological background of divergent susceptibility to mastitis in cattle and will characterize the consequences of the divergent host predisposition on the adaptation of Staphylococcus aureus to conditions within the host. Previous studies had shown that indirect markers can be applied for selecting cows with a superior immune defence mechanisms in the udder compared (Q genotypes) compared to individuals with increased susceptibility to mastitis (q genotypes). The immunological processes behind this difference are unknown. Thus, this project will investigate the genetically determined divergent immune response capacity in the udder in a comprehensive approach to define biomarkers as suitable selection tools for practical application in cattle breeding. Holstein Friesian heifers with divergent genotypes will be selected from the active breeding population prior to first calving and will be experimentally infected after calving with the model pathogens S. aureus and E. coli. The immune capacity of the individuals will be characterized prior to infection by monitoring of blood and milk cells as well as milk antibodies. Subsequently, the course of the infections will be investigated clinically and immunologically. The interconnection of S. aureus adaptation, invasion and persistence and the genotype of the host will be revealed and udder-specific molecular-immunologic processes will be analysed. The obtained results will be evaluated regarding transfer into practical application together with the industrial partner within the project.