The question as I understand it is intentional killing. Nobody eats an apple with the intention of wiping out a colony of nematodes. Nor do we rejoice in the collateral killing of life in the harvesting of say, wheat. But when a pig is converted to bacon, there's no getting around the intention of killing -->food. However, it's a diluted intention for the person buying meat from the store as the killing was done several steps away by the person who actually took the life.
And here is where the tricky part comes in: is the law of supply and demand an economic law or a moral law? Or Both?
And in that vast field of speculation much circumlocution and moralizing will occur as everyone will have different degrees of responsibility they're willing to assume based on their sensitivity to the issue. Some people are willing to take on the suffering of the entire world. I found this a job with few benefits and practically no retirement opportunities.