ABSTRACT
Genetic variation in immunity and disease resistance in dairy cows and other livestock Michael Stear, Karen Fairlie-Clarke and Nicholas Jonsson, University of Glasgow, UK; Bonnie Mallard, University of Guelph, Canada; and David Groth, Curtin University, Australia
1 Introduction
2 Genetic variation in resistance to disease
3 The sources of genetic variation in resistance to disease
4 Strategies for breeding to increase resistance to disease
5 Case study 1: resistance to cattle tick infestation
6 Case study 2: mastitis in cattle
7 Case study 3: bovine respiratory disease (BRD) complex
8 Case study 4: additive and non-additive genetic variation
9 Conclusions
10 Where to look for further information
11 References
Genetic variation in susceptibility to most diseases has been known for some time (Nicholas, 1987) and the existing genetic variation can be exploited to help control disease (Berry et al., 2011; Stear et al., 2012). The purpose of this chapter is to discuss the extent of genetic variation and explore the most suitable ways of enhancing disease resistance. Although there is considerable exploitable genetic variation in resistance to diseases caused by nutritional deficiency, toxicity, structural abnormality and metabolic dysfunction and some of this variation might be associated with components of the immune system, this chapter concentrates on resistance to infectious and parasitic disease exclusively.
