Read up on Kerry cows...evolved to eat rough vegetation, climb hills etc. Great butter and cream. Good at delivering calves. Great for some marginal situations. However..very hard to get female calves. Can get male calves and breed with another somewhat similar type of cow and so they are half Kerry..not sure how the genetics plays out. In a few generations you could get about 93% Kerry but would only get what was passed on via male side, which would of course include female stuff as well...perhaps DNA testing would separate offspring into higher Kerry content from male maternal DNA.   mg