The Chondro gene, short for CHONDRODYSPLASIA, is what gives some cattle their short legged stature. It is not a "bad" thing to be avoided. There is no risk if the gene is managed properly.  But breeding “chondro” cattle can even be fatal for calves if two carriers breed. It is important to have genetic testing to confirm the presence or absence of the gene. You never want to breed a chondro positive cow with a chondro positive bull.  The risks to the calf are just too high.