Genetic Improvement of Udder Health

Susceptibility to mastitis is in part determined by genetics. Opportunities exist for genetic improvement of resistance to mastitis but currently available means for genetic selection are limited and focus mainly on EBV for SCC and, in countries with health recording, on EBV for clinical mastitis. Further opportunities exist to incorporate available EBV for udder conformation and milking speed in selection criteria for udder health. Research on alternative methods of analysis of test-day SCC, on functionality of somatic cells in milk, on immune parameters, and on detecting genes affecting resistance to mastitis, either through candidate genes (BoLA) or anonymous genetic markers, offers perspectives to further enhance genetic improvement of resistance to mastitis. Use of this information will require further insight into the basis of resistance to mastitis. The main limitation of this research is absence of large-scale field recording programs for clinical and subclinical mastitis. In the future, clinical data may be provided by herd health management programs but accuracy of data will require continuous monitoring.