Chicken Nutrition

Good nutrition is one of the most important factors influencing the health, welfare and longevity of chickens. A balanced diet supports growth, egg production, feather quality, immune function, reproduction and disease resistance. Unfortunately, nutrition is also one of the areas where we see the most misinformation.

There is no single "perfect" chicken diet that suits every bird. Nutritional requirements change throughout life depending on age, breed, whether a bird is laying eggs, whether it is growing, recovering from illness or simply being kept as a companion.

This guide explains the different types of commercial feeds available, how to choose the right one for your flock, and how treats, supplements and free ranging fit into a healthy diet.

Understanding Nutritional Requirements

A chicken's diet is much more than simply filling its crop. Every mouthful provides the nutrients needed for growth, egg production, feather development, immune function, reproduction and maintaining normal body functions. A quality complete feed is carefully formulated to provide these nutrients in the correct balance. Deficiencies or imbalances can quickly lead to poor performance, illness and reduced productivity.

Water (highest Importance)

Water is arguably the most important nutrient in a chicken's diet. Every cell and organ relies on an adequate supply of clean, fresh water to function properly. Water regulates body temperature, transports nutrients, aids digestion, removes waste products and is essential for egg production.

Providing water is only part of the equation. Water quality is equally important. Dirty drinkers, biofilm, algae and contamination from wild birds or rodents can all increase the risk of disease. Cleaning and sanitising drinkers regularly, rather than simply topping them up, is one of the simplest and most effective ways to improve flock health.

Many poultry keepers also choose to acidify their drinking water using organic acid products. Maintaining a water pH between 5.5 and 6.5 can help reduce bacterial growth within the drinking system while supporting a healthy digestive tract. Always follow the manufacturer's directions, as excessively acidic water may reduce palatability and discourage birds from drinking.

Protein

Protein is one of the most important nutrients in a chicken's diet. It provides the amino acids needed to build muscles, feathers, skin, organs and eggs. Growing chicks require higher levels of protein to support rapid development, while laying hens need adequate protein to maintain egg production and replace feathers during moulting.

The protein in commercial poultry feeds generally comes from two main sources, animal-based proteins and vegetable-based proteins. Animal proteins, such as fishmeal or meat meal, are typically more biologically available because their amino acid profile closely matches the nutritional needs of chickens. Vegetable proteins, including soybean meal, canola meal and peas, are widely used and provide excellent nutrition, but they are generally less digestible. To improve nutrient absorption, many quality feeds include digestive enzymes that help birds extract more nutrition from these plant-based ingredients.

A lack of protein can result in poor growth, weight loss, poor feather quality and reduced egg production, while excessive protein provides little benefit and simply increases nitrogen excretion.

Energy

Energy fuels every process within the body. Chickens rely on energy to grow, move, maintain body temperature, digest food, produce eggs and support their immune system. Most dietary energy comes from carbohydrates, such as wheat and maize, although fats also contribute.

If a diet does not provide enough energy, birds will lose weight, become less productive and may struggle to maintain condition. Conversely, diets that provide too much energy, particularly through excessive treats or grains, can lead to obesity, fatty liver disease and reduced reproductive performance. Maintaining the correct balance between energy and other nutrients is essential for long-term health.

Fat

Fat is a concentrated source of energy and supplies essential fatty acids that chickens cannot produce themselves. These fatty acids play an important role in feather quality, skin health, brain function, reproduction and the absorption of fat-soluble vitamins, including vitamins A, D, E and K.

Although chickens only require relatively small amounts of dietary fat, it remains an essential part of a balanced diet. Too little fat can affect overall health and feather condition, while excessive fat intake may contribute to obesity, fatty liver disease and reduced productivity, particularly in backyard birds with limited exercise.

Fibre

Unlike cattle or sheep, chickens cannot efficiently digest large amounts of fibre. However, moderate amounts of fibre are beneficial and help maintain normal digestive function by encouraging healthy gut motility and supporting beneficial bacteria within the digestive tract.

Appropriate fibre levels also encourage natural foraging behaviour and help birds feel satisfied between meals. Diets containing excessive fibre reduce nutrient digestibility and may prevent chickens from consuming enough energy and protein to meet their nutritional requirements.

Vitamins and Minerals

Vitamins and minerals are required in relatively small amounts but are essential for almost every function within the body. They support bone development, eggshell formation, muscle and nerve function, immunity, reproduction and normal metabolism.

A quality complete feed is formulated to provide these nutrients in the correct balance, meaning additional supplementation is often unnecessary for healthy birds. However, periods of illness, stress, moulting, breeding or extreme weather may temporarily increase a bird's nutritional requirements, making targeted supplementation beneficial.

The Feed Dictionary

A complete commercial feed should form the foundation of every chicken's diet.

Commercial feeds are carefully formulated to provide the correct balance of protein, energy, vitamins, minerals and amino acids required for each stage of life. While chickens naturally enjoy grazing, scratching and hunting for insects, these foods should supplement a balanced diet rather than replace it.

Think of commercial feed as your chicken's main meal. Everything else is an extra.

Chick Starter Feed

Suitable for: Day old chicks to approximately 6 to 8 weeks of age.

Starter feed is formulated to support rapid growth during the first weeks of life. It is typically high in protein, around 18 to 22%, with balanced energy, vitamins and minerals to support muscle, feather and immune system development. Most starter feeds are available as a crumble, making them easy for young chicks to eat.

Some starter feeds contain a coccidiostat to help reduce the impact of coccidiosis while chicks develop natural immunity.

Medicated Feed

Suitable for: Primarily young chicks, depending on the feeding program.

Medicated feeds contain a coccidiostat, which helps reduce the multiplication of coccidia while young birds develop natural immunity. It is designed to help prevent clinical coccidiosis during the highest risk period but does not treat birds already suffering from the disease.

Grower Feed

Suitable for: Approximately 6 to 18 weeks of age.

Grower feed supports steady growth once the rapid growth phase has slowed. Protein levels are typically around 15 to 17%, while calcium is reduced to prevent excessive intake before birds begin laying.

It is designed for replacement pullets and growing birds, rather than meat chickens.

Layer Feed

Suitable for: Hens that have started laying eggs.

Layer feed contains around 15 to 17% protein and a much higher calcium content, usually around 3.5 to 4.5%, to support eggshell production and ongoing egg laying.

It should only be introduced once hens begin laying and is generally not recommended for chicks or roosters.

Scratch feed

Suitable for: Adult chickens as an occasional treat or enrichment.

Scratch feed is a mixture of whole or cracked grains such as wheat, maize, barley and oats. Some commercial mixes may also include sunflower seeds, peas or a small amount of molasses to improve palatability.

It is relatively low in protein, vitamins and minerals and is intended as an energy source rather than a complete diet. Scratch feed should only be offered in moderation and should never replace a balanced commercial feed.

Meat Bird Feed

Suitable for: Broiler and meat chickens.

Meat bird feed is formulated for rapid growth and efficient feed conversion. Protein levels generally range from 18 to 22%, depending on the stage of production, and the diets are higher in energy than standard grower feeds.

These feeds are designed for birds being raised for meat rather than long term health or egg production.

Organic Feed

Any age or class of bird, provided the correct formulation is selected.

Organic feeds are nutritionally similar to conventional feeds but are manufactured using certified organic ingredients and production systems. Starter, grower and layer formulations are all available.

The most important consideration is choosing a feed that matches your bird's age and stage of life, regardless of whether it is organic or conventional.

Whole Grains

Suitable for: Adult chickens as a supplement or enrichment.

Whole grains such as wheat, maize (corn), barley and oats are commonly fed to backyard chickens. While they can provide energy and encourage natural foraging behaviour, they are not nutritionally complete and should not replace a balanced commercial feed.

Whole grains are naturally lower in protein, vitamins, minerals and several essential amino acids than formulated poultry feeds. If offered, they should only make up a small proportion of the overall diet and birds should have access to insoluble grit to help grind the grains in the gizzard.

Fermented Feed

Suitable for: Adult chickens as an alternative method of feeding a complete ration.

Fermented feed is made by soaking a complete commercial feed in water for several days, allowing natural fermentation to occur. Many keepers report improved palatability and reduced feed wastage, while some studies suggest fermentation may improve nutrient availability and support beneficial gut bacteria.

Fermentation does not make an unbalanced diet complete, so it should only be used with a nutritionally balanced commercial feed. Good hygiene is essential, as incorrectly fermented feed can spoil and become unsafe.

Sprouted Graimrain

Suitable for: Adult chickens as an alternative method of feeding whole grains or as an enrichment tool.

Sprouted grain is produced by soaking whole grains in water until they begin to germinate. During sprouting, natural enzymes become active, which can improve the digestibility of some nutrients and increase the availability of certain vitamins. Many keepers also find that chickens readily consume sprouted grains, making them a useful form of environmental enrichment.

Sprouted grain should be viewed as a supplement rather than a complete diet. While it may provide some nutritional benefits over dry whole grain, it does not replace the balanced nutrition found in a complete commercial feed. Good hygiene is essential throughout the sprouting process, as mould or bacterial contamination can develop if the grains are not rinsed regularly or are left in unsuitable conditions.

Pellets, Crumble and Mash

  • Pellets

    Pellets provide complete nutrition in every mouthful, reducing selective feeding and minimising waste. They are generally the preferred option for adult birds.

  • Crumble

    Crumble is made from broken pellets and is commonly used for chicks and growing birds. It is easier for smaller birds to eat while still providing balanced nutrition.

  • Mash

    Mash is a finely ground feed. While some keepers prefer it, chickens can selectively eat certain ingredients, leading to a less balanced diet and increased feed wastage.

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Free Choice Calcium

Laying hens require significantly more calcium than growing birds or roosters because each eggshell contains a large amount of calcium. While most quality layer feeds already contain calcium, offering a separate free-choice calcium source allows hens to consume additional calcium when they need it, particularly during peak lay.

Common free-choice calcium sources include:

  • Oyster shell
  • Crushed limestone
  • Commercial poultry shell grit
  • Crushed baked eggshells

When sourcing calcium, purchase products from reputable suppliers whenever possible. Natural products such as oyster shell can occasionally contain contaminants, including heavy metals or environmental pollutants, depending on where they were harvested. If recycling eggshells, they should be thoroughly cleaned and baked before being crushed to reduce the risk of transmitting disease back to your flock.

The Supplement Dictionary

Core Supplements

Electrolytes

Electrolytes contain essential minerals, including sodium, potassium and chloride, that help regulate hydration, nerve function and muscle activity. They are particularly beneficial during heat stress, illness, transport or following dehydration. Always use a commercially formulated poultry electrolyte, as homemade recipes can contain incorrect salt concentrations that may cause osmotic diarrhoea and worsen dehydration.

Probiotics

Probiotics contain beneficial bacteria that help maintain a healthy balance of microorganisms within the digestive tract. A healthy gut microbiome supports digestion, nutrient absorption, immune function and resistance to disease. Probiotics are particularly useful following antibiotic treatment, digestive upset or other stressful events that may disrupt the normal gut flora.

Prebiotics

Prebiotics are specialised fibres that feed the beneficial bacteria already living in the digestive tract. Unlike probiotics, they do not contain live bacteria themselves. Instead, they help beneficial microbes multiply, supporting digestion, nutrient absorption and immune function. Common prebiotics include mannan-oligosaccharides (MOS), fructo-oligosaccharides (FOS), inulin and beta-glucans. Many modern poultry supplements combine both probiotics and prebiotics, known as synbiotics, to support a healthy and balanced gut microbiome.

Multivitamins

Vitamin supplements provide additional nutrients that support the immune system, growth, reproduction and normal body function. They can be particularly useful during periods of illness, stress, moulting, breeding or when birds have a reduced appetite. Vitamin supplements are best used as short-term support unless otherwise recommended.

Organic Acid

Organic acids help lower the pH of the digestive tract and drinking water, creating a less favourable environment for many harmful bacteria while supporting digestion, nutrient absorption and gut health. Common organic acids include formic, propionic, lactic and citric acid, while apple cider vinegar is a natural source of acetic acid that many backyard poultry keepers also use. Although apple cider vinegar may offer some benefits, commercially formulated organic acid blends provide a more consistent and controlled approach to water acidification and gut health support. Organic acids are also widely used in modern poultry production to help maintain water hygiene and promote a healthy intestinal environment.

Advanced Supplements

Digestive Enzymes

Digestive enzymes help chickens break down nutrients that would otherwise be poorly digested, improving nutrient availability and reducing feed wastage. They are particularly beneficial in feeds containing vegetable proteins or high levels of cereals. Common enzymes include protease (breaks down proteins), phytase (releases phosphorus bound to phytate), xylanase (breaks down cereal fibres) and amylase (helps digest starches).

Humic Acids

L-Carnitine

Omega-3 Fatty Acids

Phytogenics

Milk Thistle

Yeast Products

Treats and Extras

Treats can provide variety, enrichment and enjoyment, but they should never replace a balanced commercial feed. They should make up no more than 10% of the overall diet.

Kitchen Scraps: Fresh vegetable trimmings, cooked vegetables and other wholesome leftovers can be offered in moderation. Avoid spoiled, mouldy or heavily processed foods.

Fruits: Most fruits are safe and provide vitamins and antioxidants. Feed in moderation due to their natural sugar content.

Vegetables: One of the healthiest treats, vegetables provide vitamins, minerals, fibre and excellent enrichment. Leafy greens, broccoli, pumpkin, carrots and peas are all good choices.

Herbs: Herbs such as oregano, thyme, parsley, basil, mint and rosemary are safe and provide enrichment along with beneficial plant compounds.

Mealworms: High in protein but also very high in fat, containing around 25 to 35% fat. Feed sparingly as an occasional treat.

Black Soldier Fly Larvae: Rich in protein and naturally high in calcium, with less fat than mealworms, making them an excellent treat for laying hens.

Grains: Wheat, maize, barley and oats provide energy and encourage natural foraging but are not nutritionally complete.

Bread: Safe in small amounts but of little nutritional value. It should only be fed occasionally.

Rice: Both cooked and uncooked rice are safe. It provides carbohydrates for energy but is low in essential nutrients and should only be an occasional treat.

Dairy: Small amounts of fermented dairy, such as plain yoghurt, can be offered occasionally, but dairy should never become a regular part of the diet.

Harmful foods

  • Avocado (skin, stone and leaves)
  • Chocolate
  • Caffeine (tea, coffee or energy drinks)
  • Alcohol
  • Green potato skins and sprouts
  • Raw or dried beans (unless properly cooked)
  • Mouldy or spoiled food
  • Highly salty foods
  • Excessively sugary foods and
  • confectionery
  • Raw onion and excessive garlic
  • Fruit stones and apple seeds in large quantities
  • Garden plants known to be toxic, such as foxglove, oleander and yew

Chicken Health Basics

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