Crossbreeding cows has become the new normal for Birkstead Holsteins in Elora, Ontario. Thomas Wantenaar and his family have been experimenting with Holstein crosses since the early 2000s, around the same time Wantenaar graduated university and began working on the farm full time. Of the farm’s 310 cows, only 55 are purebred Holsteins, the rest of the herd is a variety of Holstein crosses.