How many cows are there in a mcdonalds burger?

The answer depends on the origin of the hamburger. When made by a home cook or a local restaurant where beef is produced and purchased locally, the ground meat might come from only one animal. However, the vast majority of ground beef is purchased from one of a very few giant meat-packing corporations that sell beef through huge supermarket chains. These meat-packing plants butcher thousands of cattle every hour. Meat and trimmings from all the cattle is combined in machines that grind meat for Hamburgers. So any random package of commercial ground beef could include particles of meat from hundreds or even thousands of individual animals.