I'm certain a system could be devised to allow enough pasture-raised cattle, chickens and pigs to be raised in happy, healthy conditions until slaughtered for food. It would take more resources, but it would be worth it. It might also support the plant ecosystems more, because soyabean and grain monocultures won't be needed.

However, the current Capitalist system's greed will ensure that this doesn't happen, because of the junk/fast food industry and their advertizing.

Without junk/fast food's demands, the amount of meat required to sate the global population may actually shrink, because with proper education, food addiction may vanish, meaning we'll only need to eat what we actually need for nutrition and not for addiction's sake.