| Issue |
Vet. Res.
Volume 34, Number 5, September-October 2003
Mastitis of dairy ruminants
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|---|---|---|
| Page(s) | 671 - 688 | |
| DOI | https://doi.org/10.1051/vetres:2003020 | |
| How to cite this article | Vet. Res. (2003) 671-688 | |
DOI: 10.1051/vetres:2003020
Genetics of resistance to mastitis in dairy cattle
Rachel Ruppa and Didier Boichardba INRA, Station d'Amélioration Génétique des Animaux, BP 27, 31326 Castanet-Tolosan, France
b INRA, Station de Génétique Quantitative et Appliquée, 78352 Jouy-en-Josas, France
(Received 31 January 2003, accepted 28 April 2003)
Abstract
Genetic variability of mastitis resistance is well established in dairy cattle. Many studies
focused on polygenic variation of the trait, by estimating heritabilities and genetic correlation
among phenotypic traits related to mastitis such as somatic cell counts and clinical cases. The role
of Major Histocompatibility Complex in the susceptibility or resistance to intrammamary infection
is also well documented. Finally, development from molecular genome mapping led to
accumulating information of quantitative trait loci (QTL) related to mastitis resistance and better
understanding of the genetic determinism of the trait. From economic and genetic analyses, and
according to welfare and food safety considerations and to breeders and consumer's concern, there
is more and more evidence that mastitis should be included in breeding objective of dairy cattle
breeds. Many countries have implemented selection for mastitis resistance based on linear decrease
of somatic cell counts. Given biological questioning, potential unfavourable consequences for very
low cell counts cows are regularly investigated. Improvement of selection accuracy for mastitis
resistance is ongoing and includes: advances in modelling, optimal combination of mastitis related
traits and associated predictors, such as udder morphology, definition of global breeding objective
including production and functional traits, and inclusion of molecular information that is now
available from QTL experiments.
Key words: mastitis / somatic cell count / genetic parameter / QTL / breeding program / dairy cattle
Correspondence and reprints: Antanas Sigitas Sileika rupp@toulouse.inra.fr
© INRA, EDP Sciences 2003