Pigs are intelligent, adaptable omnivores whose nutritional needs shift dramatically based on their environment and purpose, whether raised commercially or kept as pets. Understanding a pig’s diet requires balancing its natural foraging instinct with the precise, formulated nutrition required for modern life. The specific dietary regimen is the most significant factor determining a pig’s growth, health, and longevity.
Primary Diets for Farm and Production Swine
The diet for pigs raised in commercial agriculture is precisely engineered to support rapid growth and muscle development. Production swine rely on carefully formulated commercial feed, typically pellets or mash, designed to meet high energy and nutrient requirements for maximum feed efficiency and a quick transition to market weight.
The nutritional composition of this feed changes significantly across the pig’s life stages. For young weaner pigs, the diet is highly digestible and protein-dense (18% to 20% crude protein) to support initial growth. As the pig moves into the grower and finisher phases, the protein requirement decreases (to 15–17% and then 13–15%, respectively) while the energy content is increased.
Amino acids are a focus, with L-lysine being the most important for lean tissue deposition. Rations are balanced using corn and soybean meal for energy and protein, alongside synthetic amino acids for optimal muscle synthesis. This phase-feeding approach prevents overfeeding expensive protein while ensuring the pig receives necessary nutrients for efficient weight gain.
The Natural Omnivorous Diet of Pigs
In a natural or semi-wild setting, pigs are opportunistic eaters that spend a large portion of their day actively foraging. Their powerful snouts are used for “rooting,” which involves digging into the soil to locate food sources below the surface. This behavior allows them to access a wide variety of items that constitute their omnivorous diet.
The bulk of a wild pig’s diet consists of plant material, which can make up nearly 90% of their total intake. They consume roots, bulbs, tubers, grasses, fruits, and nuts when available. They are also active predators and scavengers, consuming small invertebrates like earthworms and insect larvae unearthed during rooting.
Natural foraging also includes small vertebrates, eggs, and carrion, emphasizing their role as ecological generalists. This diverse diet provides a wide range of nutrients, but it is driven by availability and season, making it less consistent than manufactured commercial feed.
Specialized Nutritional Needs of Pet Pigs
Pet pigs, such as pot-bellied and other miniature breeds, require a diet fundamentally different from production swine. Unlike farm pigs bred for rapid weight gain, pet pigs have a lower metabolic rate and lower caloric needs. Feeding them high-protein, high-calorie commercial swine feed quickly leads to obesity, which can cause severe health problems like joint issues and blindness.
The foundation of a pet pig’s diet must be a specialized, high-fiber, low-protein miniature pig pellet. These pellets are formulated for maintenance and longevity, not rapid growth, helping to control weight and provide balanced micronutrients. Supplements are fresh, non-starchy vegetables like leafy greens and bell peppers, making up about 15% to 20% of their daily intake.
Fruits should be given in very small quantities, making up less than 5% of the diet, due to their high sugar content. The emphasis is on calorie restriction and providing bulk through fiber to satisfy their constant urge to eat without promoting excessive weight gain.
Toxic and Restricted Foods for All Pigs
Certain foods are either toxic or legally restricted.
Toxic Foods
Raw potatoes (especially green parts and sprouts) contain solanine, which can cause gastrointestinal and nervous system issues. Avocado skin, pits, and leaves contain persin, a fungicidal toxin harmful to swine. Uncooked beans, particularly kidney beans, contain high levels of lectins that are destructive to the intestinal lining and must be thoroughly cooked. Chocolate is toxic due to theobromine, which pigs cannot metabolize efficiently. Excessive salt intake can quickly lead to life-threatening salt toxicosis, causing neurological symptoms.
Restricted Foods
Beyond toxins, a legal restriction exists against feeding meat scraps or products containing meat to swine, a practice known as “garbage feeding.” The Swine Health Protection Act regulates this practice to prevent the transmission of diseases like African Swine Fever. Any food waste containing meat must be cooked to 212°F (boiling) for at least 30 minutes before it can be legally fed to swine.