Here are two great sites with statistics on animals killed by food consumption.

AnimalVisuals, which includes a nice graphic showing "Rate of Slaughter of Chickens, Pigs, and Cows in the United States, 2008" and other cool graphs and demos.

The Counting Animals blog, which includes a great new post on "How many animals does a vegetarian save?." [Answer: "A vegetarian, therefore, saves at least 400 animals per year (30 land animals, 219 fish and 151 shellfish)."]

Do you agree with the latter, after indirect killing is taken into account?

Harish's estimates seem pretty reasonable even without indirect killing, no? If you count indirect killing, the numbers might be a few times higher.

Of course, killing is not equivalent to suffering, but "numbers killed" and "numbers that suffer" are often pretty correlated.

Oh, oops, I misunderstood your question. I guess you were saying that vegetarians (and even vegans) kill lots of animals through plant agriculture, so the baseline number killed is still nonzero. Yes, but most farm animals are fed many times more food than what they themselves yield, which is why I said the numbers were probably understated due to not counting indirect killing.

Yeah, sorry. Ok.