Taco Bell uses at least 600,000 cows' worth of beef per year. According to Taco Bell's own website, they serve an average of 295 million pounds of ground beef every year. So let's do some math. The average beef steer yields approximately 570 pounds usable cuts (the rest of this 1,150 or so pounds are unusable parts like bone and organs).

So, 295 million pounds of beef divided by 570 pounds of beef per cow comes out to... about 517,543 cows. Per year. For Taco Bell.
 Doesn't something feel a little unsettling about Taco Bell requiring half a million cows to die every year?