Show a cow you care! Although we cannot find the official origin of this day, we are happy to join all the nice midwestern folks in celebrating our mooing friends. Did you know that cows: have 32 teeth, chew cud for up to 8 hours each day, have 4 digestive compartments (not 4 stomachs), and can provide 25 gallons of milk (each) per day. About 9.2 million cows are being milked each day in the United States alone.