Any industrial scale animal agriculture has as an input industrial scale plant production. For example, most of the plant matter produced for consumption in the US goes not to humans, but to animal agriculture instead.
Any issues in plant agricultural production will be felt many times over in prices for meat (either via subsidy or at the counter) than in prices for plants.
Plant diseases are caused by animal agriculture operations for the more part. E.Coli and salmonella are two big ones that were on salad greens recently. Guess what - they didn't originate from the plants. They are 100% animal (or human) based.
Manure, contaminated water, runoff - all contributing factors to "plant diseases", all issues from raising animals for food.
E. coli and salmonella aren't plant diseases. They make humans sick, not plants. Plant diseases are stuff like pseudocercospora, which are on track for eradicating the most common bananas grown today, despite attempts at quarantining affected regions to stop the disease from spreading.
You must have misread what I wrote because I never claimed that they were. I put quotes around "plant diseases" because the two major outbreaks that everybody thinks about weren't plant diseases, they were animal-related.
I don't know if this is a good faith question or not. But of course the concern isn't people getting diseases from plants.
Crop yields go down and in some cases the resulting grain becomes poisonous to people or animals which can in some cases cause disease (fungal most often).
You're correct. Pigs are very similar to humans anatomically, and biochemically mammals share a LOT of genetics, so its much easier for mutations to lead to species hopping pathogens.
This is one reason why Eurasian cultures dominated historically speaking: they'd lived with livestock for much longer and evolution crafted those human populations to have numerous immunities that isolated, non livestock holding communities didnt have.
Put in another way or with another interpretation: the arms race between disease and immune system in the animal-human-disease relationship led to very powerful diseases which the humans carried in their populations but were not largely affected by.
When the Europeans started crossing oceans to contact very different civilizations they brought the diseases which themselves committed genocide because the new populations hadn't had the same difficulty or interactions with animals and diseases.
Animal agriculture won't stop.
This disease process eliminates bad management and corrupt inefficient government.