Demand is driven primarily by domestic and international trends in pork consumption. The profitability of individual companies depends on efficient operations and reducing the spread of disease. Large companies have advantages in vertically integrating operations from birthing to packaging and distribution. Small operations, typically family-owned farms, can compete by specializing in a single stage of hog farming or by raising animals that are humanely treated, antibiotic-free, or otherwise tailored to buyers' specifications. The US industry is concentrated: about 20% of farms account for about 95% of sales.