Having grown up on a farm, I'm very familiar with this term.  Female cattle are referred to as heifers until they give birth, and then they are  referred to as cows.  The term heifer was first used to refer to a 'woman' or a 'girl', but eventually the term was basically used only when referring to female bovines. 

The is an Old English word that come from an older origin that means 'to produce' or 'to bring forth'.

My mom used to watch "the View" and soon change channels in disgust.

She would say, "I can't believe those heifers are so stupid."

I'd say, "Mom, those cows get more stupid every day."

4 hours ago, drpaladin said:

They are also way, way too old to be heifers. Some are at the carbon dating stage.

Well, Mom was 90 at the time, so to her, they were just dumb yungins.

A 90's kid would remember Heifer as a fun gluttonous cartoon steer:

He was really fond of Chokin Chicken (Did not know until I was much older that was a reference to masturbation, you gotta love subversive cartoons)

And talk about perfect timing, when I collected my mail today, I had a letter from Heifer International.  It's a non-profit charity whose goal in ending hunger and poverty.  Not sure how they decided to name this organization, but their timing was perfect with today's "Word of the Day".