Whatever suffering it takes, we need animal farming to feed 8 billion people
Animal farming is not what makes it possible to feed 8 billion people. Animals eat far more food than they give back, so using crops directly feeds more people from less land. If the suffering is only justified because it is necessary, the justification fails at that step.
Feeding 8 billion people is the most important thing any food system has to do. Animal farming turns grass, crop residues and land that can't grow crops into dense protein and nutrients, and billions of people rely on it. If some animal suffering is the price of keeping people fed, that is a hard trade but a defensible one, and it shouldn't be judged as if it were only about taste.
The numbers run the other way. Livestock and their feed take up roughly three-quarters of the world's farmland but supply under a fifth of its calories and well under half its protein. A chicken, pig or cow eats several kilograms of feed for each kilogram of food it yields. Large studies of the global food system estimate that a plant-based world would need around three-quarters less farmland while feeding the same population. Feeding everyone is easier without the animals in the middle, not harder.
Some land is fit only for grazing, and some communities depend on herding because nothing else grows. That is a real case, and the standard definition of veganism already allows for it through necessity. It describes a small share of the meat produced. Most meat eaten in wealthy countries, including nearly all chicken and pork, comes from animals fed on crops grown on land that could feed people directly.
Hunger today is mostly a problem of poverty, conflict and distribution. The world already grows more than enough calories for everyone. A large share is fed to animals rather than reaching the people who need it, sometimes in countries where people are going hungry.
The claim also grants the principle it was meant to resist. 'Whatever it takes' means the suffering is acceptable only because it is needed. That is the vegan position: avoid suffering that isn't necessary. So the remaining question is whether this particular chicken, bought by this particular person, was needed to feed anyone. For most people reading this, it wasn't.
Presenting two options as though they were the only ones available when further options exist. Also called a false dichotomy, or black-and-white thinking.
How it applies here: It frames the choice as accepting the suffering of farmed animals or failing to feed 8 billion people. A third option, growing crops for people instead of for animals, is left out, even though it feeds more people from less land.