A cow's natural lifespan is about 25 years, but cows used by the dairy industry are killed after only four or five years. An industry study reports that by the time they are killed, nearly 40 percent of dairy cows are lame because of the intensive confinement, the filth, and the strain of being almost constantly pregnant and giving milk. Dairy cows' bodies are turned into soup, companion animal food, or low-grade hamburger meat because their bodies are too "spent" to be used for anything else.
The website the meat industry doesn't want you to see: http://meat.org
How to go vegan: http://features.peta.org/how-to-go-vegan/
PETA Saves: http://features.peta.org/petasaves/