The chicken, historically descended from the Red Junglefowl of Southeast Asia, is an omnivorous scavenger. These birds do not rely on a single food source but discover a wide variety of items through constant, active foraging. When left to their own devices, a chicken’s diet reflects its immediate environment and the season, providing the full spectrum of protein, carbohydrates, fats, and micronutrients needed for survival. Chickens are opportunistic feeders that thrive on variety, not specialized herbivores or carnivores.
The Role of Insects and Invertebrates
Animal protein, primarily sourced from various invertebrates, is a key part of the natural chicken diet. Chickens are highly adapted to scratch and peck at the soil, uncovering a rich source of high-energy food. They instinctively search for these sources because they provide concentrated nutrition necessary for growth, maintenance, and egg production.
The protein they consume is derived from a wide range of creatures, including earthworms, slugs, snails, and various insect larvae, often referred to as grubs. Specific insects like termites, ants, grasshoppers, and beetles are regularly consumed, providing amino acids and fats critical for feather health and vigor. This intake of animal matter ensures the chicken receives a complete protein profile, which is difficult to obtain solely from plant sources.
Foraged Greens, Seeds, and Fruits
The bulk of a chicken’s natural caloric intake comes from the vast array of plant matter they consume. This part of their diet is highly variable, changing with the availability of resources throughout the year. Chickens graze on soft, young grass blades and are particularly fond of common weeds like clover and dandelion greens, which offer a dense supply of vitamins and minerals.
They actively seek out wild seeds and fallen fruit, which are excellent sources of carbohydrates and energy. This includes berries and kernels of grain found in fields after harvest. Chickens often scratch to expose roots and tubers, accessing starches and additional nutrients just beneath the soil surface. They also consume the foliage of nitrogen-fixing plants like clover, which contribute to a healthy gut microbiome.
The consumption of seeds, nuts, and grains is important as a source of energy. They actively break open seed heads and scratch through leaf litter to find these small, calorie-dense items. Seasonal changes dictate what is available; fruits and seeds are more abundant in late summer and fall, while tender greens are more prevalent in spring.
How Chickens Process Natural Foods
Chickens lack teeth, meaning they must process their whole, unprocessed diet using a unique mechanical digestive system. After food is swallowed, it moves from the crop, a temporary storage pouch, into the proventriculus, or glandular stomach, where digestive enzymes and acids are secreted. These chemicals are not enough to break down tough materials like whole seeds, fibrous plant matter, or insect exoskeletons.
The gizzard, or ventriculus, acts as the bird’s internal grinder. This highly muscular organ requires the presence of insoluble grit—small, rough stones the chicken instinctively consumes. The gizzard’s powerful contractions use these stones to physically crush and grind the coarse food into a fine, digestible paste. Without this mechanical aid, the chicken cannot properly break down the hard components of its diet, leading to poor nutrient absorption.