Farmers in the US have begun implanting dairy cows with fertilised embryos of beef cattle, so they produce calves bred for beef rather than milk production. The idea is to make dairy farming more profitable.
Cattle have been bred for either milk or beef production. Beef breeds typically put on more muscle faster for less food than dairy cattle do, and the meat quality is better. This makes beef calves far more valuable than male dairy calves, which are often disposed of immediately after birth.