Dairy cow breeds have,due to selection strategies,evolved
differently in different countries depending on the relative
economic importance of different traits such as milk produc-
tion, health,fertility and beef production potential of the male
progeny.In Norway for example,decades of selection with in
the Norwegian Red breed for resistance to mastitis has
resulted in a lower incidence of clinical mastitis in the home
country population(Heringstad etal.,2003).