Cattle

Heifer: A female bovine that has not given birth to a calf. After giving birth to her first calf, a heifer becomes a cow.
Bull: A male bovine that can reproduce.
Steer: A male bovine that has been castrated and cannot reproduce. Steers are often raised for beef.
Calf: A baby bovine, either male or female.

• Black Angus cattle, also called Aberdeen Angus, are the most popular breed in the United States. They are raised for their meat.

• There are more than nine million dairy cows in this country and about 90 percent of them are Holsteins. Holstein cows are perhaps the most recognized breed of dairy cattle and are the most common dairy breed in the U.S. They have distinctive black and white or red and white markings. 

For one thing, cow's have four stomachs!  Yup, this allows a cow to graze on grass at one time, and regurgitate the "cud" at a later time to chew it and digest it at a later time.  The get every bit of nutrition out that they can from each blade of grass.  

Also, cattle have two toes on each foot versus a horse's one toe.