No they don't. Milking cows, or dairy cows are a different type of cow than beef cows are. Dairy cows give birth to dairy cows, no matter if they are crossed with a beef breed or not. The dairy-beef crossbred cow as a result still has stronger dairy qualities in her than her dairy mother.
Dairy cows have larger udders than beef cows, are typically a bit thinner, and tend to have a less blocky appearance than most beef cows. Dairy cows also have more feminine characteristics to them than beef cows do.