In 2010 the worldwide population of domesticated ruminants was estimated to be 3.6 billion [1]. Many of these animals are used for milk production or as suckler animals where the offspring are consumed for meat. These functions are dependent on the lactational capacity of the female ruminant, thus postnatal mammary development impacts future lactational productivity [2, 3] whilst mastitis is a major welfare issue that also causes financial losses [4].