Understanding Pig Nutrition Basics

Pigs are omnivores, which means they can eat a wide variety of foods — but that doesn't mean everything is appropriate or healthy for them. A well-balanced diet is fundamental to good growth, reproduction, immune function, and overall well-being. Whether you keep a single pet pig or a small farm herd, understanding nutritional requirements will help you make better feeding decisions.

The Key Nutrients Pigs Need

  • Energy (carbohydrates and fats): The primary fuel source. Cereals like barley, wheat, and maize are common energy sources.
  • Protein and amino acids: Essential for growth and reproduction. Lysine is the most critical amino acid for pigs.
  • Vitamins: Particularly vitamins A, D, E, and B-complex vitamins.
  • Minerals: Calcium and phosphorus for bone health; iron for piglets; salt for general function.
  • Water: Often overlooked but critical — pigs need constant access to fresh, clean water. A dry sow may need 10–15 litres per day; a lactating sow considerably more.

Feeding by Life Stage

Piglets (Birth to Weaning — approx. 3–8 weeks)

Newborn piglets rely entirely on their mother's colostrum in the first hours of life — this provides essential antibodies. After the first day, sow's milk provides all required nutrition until weaning. From around 7–10 days old, offering a palatable creep feed encourages early dry feed intake, which eases the weaning transition.

Creep feed should be high in digestible protein (around 20–22%), with added iron supplementation if piglets are kept indoors (as they cannot access soil iron).

Weaners and Growers (8 weeks to ~60 kg)

Post-weaning, pigs transition to a weaner/grower ration. This phase is critical — the digestive system is still developing, so feed quality matters enormously. Look for:

  • Protein content: approximately 18–20%
  • High digestibility ingredients (avoid raw legumes in large quantities)
  • Gradual feed changes — abrupt switches cause digestive upset

Finisher Pigs (60 kg to slaughter weight)

As pigs approach market weight, protein requirements decrease slightly while energy needs remain high. A typical finisher ration contains around 14–16% protein. Avoid overfeeding at this stage — excess fat deposition is wasteful and reduces carcass quality.

Breeding Sows

Sow nutrition is arguably the most nuanced area of pig feeding. Requirements change significantly between stages:

  1. Flushing (pre-mating): Slightly increase energy intake to boost ovulation rate.
  2. Gestation: Feed for body condition maintenance — typically 2–2.5 kg of a sow ration daily, adjusted for body condition score.
  3. Lactation: Dramatically increased requirements. A lactating sow may need 5–7 kg of feed daily to sustain milk production without depleting her own body reserves.

Pet and Miniature Pigs

Pet pigs are highly prone to obesity — one of the most common welfare problems in miniature pig ownership. Avoid feeding pet pigs unrestricted amounts of any food. A good approach:

  • Use a quality mini pig pellet as the dietary base
  • Supplement with fresh vegetables (leafy greens, carrots, cucumber)
  • Limit fruit due to high sugar content
  • Avoid bread, biscuits, and processed human foods

Foods to Avoid Feeding Pigs

Food ItemReason to Avoid
Meat and meat productsIllegal to feed in many countries; disease risk (e.g. African Swine Fever)
Raw potatoes and potato peelingsContain solanine, which is toxic to pigs
AvocadoContains persin, toxic to pigs
Chocolate and caffeineToxic; never feed to pigs
Mouldy or rotten foodMycotoxins cause serious illness
Kitchen scraps (in many regions)May be illegal — check local regulations

Feeding Frequency and Management Tips

Most pigs do well with twice-daily feeding at consistent times. This reduces competition and stress. Always ensure adequate trough space so subordinate pigs can eat — aim for at least 30 cm of trough space per pig. Monitor body condition regularly and adjust rations accordingly rather than feeding the same amount regardless of condition.