What Do Chickens Eat? Complete Diet & Feeding Guide

Chickens are opportunistic omnivores with a digestive system built for processing diverse foods. In natural settings, they spend most of their waking hours foraging, scratching the ground for seeds, grains, insects, worms, grubs, small lizards, and even mice. They also eat grasses, weeds, and fallen fruit.

Their digestive system includes a crop (a pouch at the base of the neck where food is stored and softened), a proventriculus (the true stomach that adds digestive acids), and a gizzard (a muscular organ that grinds food with the help of swallowed grit). Because chickens have no teeth, the gizzard is essential for breaking down food, which is why free-range and confined chickens alike need access to grit.

Chickens have a relatively short digestive tract compared to mammals, which means food passes through quickly. This makes nutrient density important — low-quality filler foods like bread take up space without providing adequate nutrition. A properly formulated commercial feed ensures that each bite delivers the protein, vitamins, and minerals chickens need.

Chickens can safely eat a wide range of supplemental foods when offered in moderation alongside their main feed.

Vegetables: Leafy greens (kale, lettuce, Swiss chard, cabbage), broccoli, cauliflower, peas, corn (on the cob or kernels), green beans, squash, zucchini, cucumber, carrots, bell peppers, sweet potatoes (cooked), and pumpkin (seeds included — a natural dewormer).

Fruits: Watermelon (a summer favorite), berries (strawberries, blueberries, raspberries), grapes (halved), apples (no seeds), bananas, cantaloupe, peaches, and pears. Fruits are sugary, so offer sparingly.

Grains & Seeds: Oats (raw or cooked), rice (cooked), wheat, barley, millet, sunflower seeds (black oil sunflower seeds are excellent for feather health), flax seeds, and scratch grains. Scratch is a treat, not a complete feed.

Protein: Mealworms (dried or live — a chicken favorite), earthworms, scrambled or hard-boiled eggs, plain yogurt (small amounts), and cooked fish or meat scraps. Extra protein is especially valuable during molting.

Herbs: Oregano, thyme, basil, parsley, mint, lavender, and rosemary. Many herbs have mild health-supporting properties and chickens enjoy them fresh or dried.

Rule of thumb: Treats should make up no more than 10-15% of total daily intake. Overfeeding treats dilutes the balanced nutrition provided by commercial feed.

Several common foods are toxic or harmful to chickens:

Toxic foods: Chocolate and caffeine (theobromine is toxic to poultry), avocado skin and pit (persin), dried or raw beans (phytohemagglutinin), rhubarb leaves (oxalic acid), and green potato skins and sprouts (solanine).

Allium family: Onions and garlic in large amounts can cause hemolytic anemia in poultry. Small amounts of garlic are sometimes used as a supplement, but large or frequent servings should be avoided.

Poor nutrition foods: Bread, crackers, chips, cookies, and other processed foods fill the crop without providing adequate nutrition. A crop packed with bread leaves less room for balanced feed, potentially leading to deficiencies over time.

Salty foods: Excess salt is dangerous for chickens and can cause salt poisoning, leading to increased thirst, wet droppings, kidney damage, and in severe cases, death.

Moldy or spoiled food: Mold produces mycotoxins that can cause serious illness in poultry. Never feed chickens food that looks or smells off. This includes moldy bread, rotting fruit, or feed that has gotten wet and started to decompose.

Apple seeds and stone fruit pits: These contain small amounts of cyanide compounds. While a few seeds are unlikely to cause harm, it is best practice to remove them before offering these fruits.

Matching the right feed to the right age is critical for healthy growth and production.

Chicks (0-8 weeks): Start with a chick starter feed containing 18-20% protein. Medicated starter (containing amprolium for coccidiosis prevention) is common but not required if chicks have been vaccinated. Provide feed and fresh water free-choice around the clock. Introduce grit by the end of the first week if chicks are eating anything besides commercial crumbles.

Pullets/Growers (8-18 weeks): Transition to a grower feed with 16-18% protein. The reduced protein supports steady growth without pushing birds to lay too early. Continue free-choice feeding. Treats can be introduced gradually but should remain a small portion of the diet.

Laying Hens (18+ weeks): Switch to a layer feed with approximately 16% protein and 3.5-4% calcium. The high calcium content supports eggshell formation. Offer crushed oyster shell free-choice as a calcium supplement so hens can self-regulate intake. Roosters and non-laying hens housed with layers should have access to an all-flock feed option if possible, as excess calcium can stress the kidneys of non-laying birds.

Molting birds: During the annual molt (usually fall), hens stop or reduce laying and grow new feathers. Feathers are about 85% protein, so extra protein is beneficial. Some keepers switch temporarily to a higher-protein feed (18-20%) or supplement with protein-rich treats like mealworms.

Broilers/Meat birds: Meat breed chickens grow rapidly and have different nutritional requirements. They typically receive a high-protein broiler starter (22-24%) followed by a finisher feed. Consult breed-specific guides for optimal feeding schedules.

A quality commercial feed is the cornerstone of chicken nutrition. Here are the main types:

Chick starter: High-protein (18-20%) crumble formulated for rapid early growth. Available medicated (with amprolium) or unmedicated. Feed from hatch through about 8 weeks.

Grower feed: Medium-protein (16-18%) formula for developing pullets from 8 to 18 weeks. Prepares birds for the transition to layer feed without the high calcium that could damage young kidneys.

Layer feed: The standard for laying hens, with approximately 16% protein and added calcium (3.5-4%). Available as pellets, crumbles, or mash. Pellets typically result in less waste.

All-flock/Flock raiser: A versatile feed (16-18% protein) suitable for mixed flocks containing different ages, sexes, or species. Supplement with oyster shell for laying hens when using all-flock feed.

Scratch grains: A mix of cracked corn, wheat, and other grains used as a treat or supplement. Scratch is NOT a complete feed — it lacks adequate protein, vitamins, and minerals. Use sparingly, especially in warm weather.

Feed forms: Pellets reduce waste and prevent selective eating. Crumbles are easier for young birds to eat. Mash is the least processed but most easily wasted. Most backyard keepers prefer pellets for adult birds.

Cost range: A 50-pound bag of conventional layer feed typically costs $15-$25. Organic and specialty feeds run $25-$45 per bag.

A complete commercial feed provides most necessary nutrients, but a few supplements are commonly recommended:

Calcium (oyster shell): Essential for laying hens. Offer crushed oyster shell in a separate container so birds can self-regulate. Do not mix calcium into the main feed, as non-laying birds do not need the extra calcium and excess can cause kidney damage.

Grit: Insoluble granite grit helps the gizzard grind food. Free-range chickens often pick up natural grit from the environment, but confined birds need it provided. Starter-size grit for chicks, regular grit for adults.

Apple cider vinegar (ACV): Some keepers add a small amount (1-2 tablespoons per gallon) to water. While scientific evidence is limited, anecdotal reports suggest it may support gut health. Do not use in metal waterers, as it can corrode them.

Probiotics: Beneficial for gut health, especially after antibiotic treatment or during stressful periods like transport, extreme weather, or flock integration.

Vitamins and electrolytes: Useful during heat stress, illness recovery, or periods of poor feed intake. Available as water-soluble powders. Use as a short-term support, not a permanent fixture.

Diatomaceous earth (DE): Sometimes added to feed or dust baths. Food-grade DE is considered safe, but its effectiveness as a dewormer or pest deterrent is debated among poultry veterinarians.

Chicken nutritional needs change with the seasons:

Winter: Chickens need more calories to maintain body temperature. Increase feed portions and consider a late-afternoon feeding of scratch grains or cracked corn — the digestion process generates body heat overnight. Ensure water does not freeze; heated waterers are a worthwhile investment. Egg production often decreases naturally with shorter daylight hours.

Spring: Laying typically increases as days lengthen. Confirm hens are on layer feed with adequate calcium. As foraging opportunities expand, chickens may eat less commercial feed but should always have it available. Spring is also when many broody hens sit, reducing their own feed intake — monitor body condition.

Summer: Heat stress is the primary concern. Chickens reduce feed intake in hot weather, which can crash egg production and cause weight loss. Offer feed during cooler morning and evening hours. Provide cold watermelon, frozen berries, or frozen peas as cooling treats. Ensure clean, cool water is always available. Electrolyte supplements can help during heat waves.

Fall: The annual molt typically occurs in fall. Increase protein through higher-protein feed or treats like mealworms and black oil sunflower seeds to support feather regrowth. As temperatures drop, gradually shift toward winter feeding routines. Evaluate body condition and address any weight loss before cold weather sets in.