A survey of current legal space requirements for common farm animals and the scientific evidence supporting more generous standards.
Current legal space standards for farm animals in most countries were set through political negotiation rather than animal behavior science. Scientific evidence consistently shows that animals need more space than current minimums provide to perform natural behaviors without stress. Broilers at maximum legal density cannot all move simultaneously. Pigs at minimum space cannot avoid persistent social conflicts. Laying hens in minimum legal cage space cannot fully extend wings or perform normal comfort movements. The gap between what law requires and what animals need is substantial, measurable, and represents an ongoing welfare deficit affecting billions of animals.