Ethical Question: Animals killed in plant production?

I was wondering if anyone here could address this argument I heard today against veganism/vegetarianism. The idea is that many small field animals, such as rabbits and mice, are accidentally killed in the growing of plants. The argument says that a lot of plants are needed to provide a plant-based meal (so many small animals killed accidentally), while the death of only one cow can feed many. Thus, from a utilitarian perspective, eating meat causes less animal lives to be lost.

I realize that one flaw in this argument is that cattle are often fed a large amount of grain and other plants, requiring a large quantity of plants just to feed a cow, meaning that meat has an even bigger hidden cost in small animal deaths. However, this is where the argument for grass-fed cattle comes in. Although I don’t believe that this is a very popular option today in factory farms, it is nevertheless an alternative that poses to be less cruel that relying directly on a plant-based diet, so I was wondering if someone could address that.

I would also like to mention that I have read one vegan counterargument that, in a nutshell, claims that “unintentional” killing for “necessary” food production is less morally repugnant than “intentional” killing for “unnecessary” food production. In other words, we need the plants anyway, and we can thus feel less guilty if we kill field animals by accident in growing them. Personally, it’s difficult for me to accept this, because my understanding of veganism entails truly minimizing harm, not merely having noble intent.

I’m sure this argument is not new to the vegan community, so could someone please tell me a bit about how they would address it?

If he’s right that it causes less harm, then eating a grass fed cow is preferable I suppose, especially if the cow is killed in a relatively painless way. And there is some land that is suitable for grazing cattle but not growing vegetables, though I’m not sure enough of that land exists to feed everyone cattle. There are also environmental concerns regarding the waste products of cows and co2 emissions. I doubt that a lot of plants are killed to provide a plant based meal. If I eat a bowl of beans then I killed, what… one bean plant? What’s the chance that an animal was killed at the same time that the plant was killed?

I mean, I guess what you need to do is figure out the amount of protein from beans from a field of the same size necessary to produce the same amount of protein as a cow. Then find how many animals are killed when those beans are harvested. Divide the number of animals killed by the number of meals people can eat from those beans. That fraction is the chance that someone killed an animal because of their meal, and something like the percentage of responsibility the person had for the death of field animals in general by consuming that meal.

Then for the cow take the number of animals killed (one) and divide it by the number of meals people can eat from it. The result is something like the percentage of responsibility someone has for the cow’s death. (Arguably whoever actually killed the cow may have a greater amount of responsibility for it, but it is the same for the farmer in the previous case with the plants)

From a utilitarian perspective, there may be some harm to society from killing animals intentionally, if we’re trying to create a truly non-specieist society. It may lead to less equality for people with lower IQs. If non-speciests are ok with the idea of intentional killing they might see a retarded orphan morbidly obese person and think “Hey I could feed my whole family for weeks with the meat from that guy. No one will miss him and he is as dumb as a cow! His existence is probably bad for the environment too!”. No one would like living in a society where everyone practices that kind of extreme utilitarian thinking. That type of utilitarian thinking would actually lead to consequences that are bad from a utilitarian perspective.