Like a lot of folks eating primarily or only plants, I dislike eating animals because I empathize with animals and feel bad about their suffering from raising them for food.
That said, how much of the suffering involved in meat consumption actually comes from the animal whose meat is consumed?
What I'm thinking about is that eating animals is O(10) times less efficient at providing calories than eating plants. This suggests that if more than 0.1 units of suffering (assuming the animal being eaten suffers 1 unit) are produced in the production of plants for food, then the suffering caused by eating meat is dominated not by the suffering of the animal being eaten but by the suffering caused in order to produce the food.
Obviously some of this is going to be hard to pin down. For example, depending on how you weigh the suffering of insects and how much pesticides are used to grow feed stock of the meat being consumed may cause wild swings in estimates, but I'd nonetheless be interested in seeing what models people have of how much suffering is caused. This might also make a suffering-oriented case for better meat choices among those who eat meat anyway. For example, maybe organic beef causes O(100) times less suffering than conventional beef because 100 times fewer insects suffer in its production?
So, any thoughts on this, what I might call the "iceberg" of suffering caused by eating meat?
A main reason I'm uncertain about the sign of crop cultivation is that I don't know if it reduces total invertebrate populations. Especially when irrigation and fertilization are used, crop net primary productivity can be somewhat higher than that of native grassland, although I also get the impression that farm fields can also be less rich in soil fauna than native ecosystems (maybe partly due to pesticides?).
I assume that insecticides are usually pretty effective at reducing populations of target (and probably at least some non-target) insect species.
OTOH, crops fields can sometimes breed much larger insect infestations than would occur in a wild ecosystem. Berryman (2008): "growing extensive monocultures of a particular plant genotype may provide a huge amount of highly susceptible food for insects that feed on that crop, and/or may create an environment that is less hospitable for some of the natural predators and parasites that attack them." That said, I feel like wild plants can also have big insect infestations. I've seen hundreds of aphids on a single wild plant near my house.