Poultry, like all animals, require a balanced diet to thrive, grow, and reproduce. They consume food to obtain the energy and building blocks necessary for essential bodily functions such as breathing, movement, digestion, and maintaining body temperature. These critical components are provided by nutrients, which are the foundation for developing bone, muscle, feathers, and eggs. While numerous elements contribute to a healthy poultry diet, understanding which nutrient reigns supreme is key to optimizing bird health and productivity.
Feed consists of six major components:
- Water
- Carbohydrates
- Fats
- Proteins
- Minerals
- Vitamins
The Indispensable Role of Water
Water is often an overlooked nutrient, yet it is arguably the most crucial. An animal can survive longer without food than without water. For laying hens, even a brief period of water deprivation can lead to a noticeable decrease in egg production, highlighting the need for constant access to clean water. If using manual waterers, they should be filled at least twice daily, as birds may deplete the water supply by midday if filled only once in the morning. Notably, laying hens consume about 25% of their daily water intake in the two hours before nightfall.
Water serves several vital roles within a bird’s body. It softens feed, facilitating its passage through the digestive system. As a major component of blood (approximately 90%), it transports nutrients from the digestive tract to cells and removes waste products. Water also plays a critical role in thermoregulation through evaporative cooling, especially important since birds lack sweat glands and rely on rapid respiration in their air sacs and lungs to dissipate heat.
Alt text: A close-up of a brown chicken drinking from a metal poultry waterer.
A chick’s body is composed of approximately 80% water, and while this percentage decreases with age, the fundamental need for water remains constant. Although there is no precise water requirement due to factors like age, condition, diet, temperature, water quality, and humidity, a general guideline suggests that poultry consume twice as much water as feed.
Carbohydrates: The Primary Energy Source
Carbohydrates, composed of carbon, hydrogen, and oxygen, are a key energy source and form the bulk of a poultry diet. They are ingested mainly as starch, sugar, cellulose, and other non-starch compounds. While poultry have difficulty digesting cellulose and non-starch compounds (referred to as crude fiber), they can efficiently utilize most starches and sugars. Common carbohydrate sources in poultry diets include corn, wheat, barley, and other grains.
Fats: Concentrated Energy and Essential Fatty Acids
Fats provide more than double the calories of carbohydrates per weight, offering nine calories per gram compared to carbohydrates’ four. Saturated fats are solid at room temperature, while unsaturated fats are liquid. Examples of saturated fats used in poultry diets include tallow, lard, poultry fat, and choice white grease, while unsaturated fats include corn oil, soy oil, and canola oil. Animal fat, poultry fat, and yellow grease are common supplemental fat sources in commercial poultry feeds. However, the cost of vegetable oils often makes their inclusion uneconomical.
Fats are composed of smaller units called fatty acids. These are crucial for cell membrane integrity and hormone synthesis. While numerous fatty acids exist, poultry have a specific requirement for linoleic acid, making it an essential dietary component. Linoleic acid is an essential fatty acid because poultry cannot synthesize it from other nutrients.
Alt text: A close-up shot of poultry feed pellets, illustrating the texture and composition of a typical chicken diet.
The presence of fat in the diet is necessary for the absorption of fat-soluble vitamins A, D, E, and K. Beyond its nutritional role, fat reduces grain dust and enhances feed palatability. To prevent fats from becoming rancid, antioxidants such as ethoxyquin are added to poultry diets, especially in warmer months.
Proteins: The Building Blocks of Life
Proteins are complex compounds composed of amino acids. After ingestion, proteins are broken down into amino acids, absorbed into the bloodstream, and transported to cells, where they are reassembled into specific proteins required by the bird. These proteins are essential for building body tissues like muscles, nerves, cartilage, skin, feathers, and beaks. Egg white is also rich in protein.
Amino acids are classified as either essential or nonessential. Essential amino acids cannot be synthesized in sufficient quantities by the animal and must be supplied through the diet. Nonessential amino acids can be produced by the body if the appropriate starting materials are available. Of the 22 amino acids commonly found in feed ingredients, 11 are essential for poultry. Poultry diets typically consist of a mix of feedstuffs because no single ingredient can provide all the necessary amino acids in the correct proportions.
While most feed tags indicate crude protein percentage, this doesn’t reflect protein quality, which depends on the presence of essential amino acids. For poultry, methionine and lysine are particularly critical. Deficiencies in either can significantly impair productivity and health. Commercial poultry diets often include methionine and lysine supplements, allowing for lower total protein content without compromising nutritional needs.
Plant-based proteins like soybean meal, canola meal, and corn gluten meal are primary protein sources in poultry diets. Animal proteins, such as fishmeal and meat and bone meal, are also used, but fishmeal is limited to less than 5% of the diet to prevent a fishy taste in meat and eggs.
Minerals: Essential for Various Bodily Functions
Minerals are crucial for bone formation and other essential functions like blood cell formation, blood clotting, enzyme activation, energy metabolism, and muscle function.
Minerals are categorized as macro- or microminerals, with poultry requiring higher levels of macrominerals and lower levels of microminerals. Microminerals include copper, iodine, iron, manganese, selenium, and zinc, all vital for metabolic processes. For instance, iodine is needed for thyroid hormone production, which regulates energy metabolism. Similarly, zinc supports enzyme-based reactions, and iron facilitates oxygen transport.
Alt text: A chicken pecking at feed from a trough, illustrating the feeding behavior of poultry.
Macrominerals include calcium, phosphorus, chlorine, magnesium, potassium, and sodium. Calcium is well-known for its role in bone formation and eggshell quality, but it’s also important for blood clot formation and muscle contraction. Phosphorus is crucial for bone development, cell membrane structure, and metabolic functions. Chlorine aids in hydrochloric acid formation in the stomach, supporting digestion. Sodium and potassium are electrolytes important for metabolic, muscle, and nerve functions, while magnesium also supports metabolic and muscle functions.
Since grains are low in minerals, commercial poultry feeds are supplemented with minerals. Limestone or oyster shell are common calcium sources, while dicalcium phosphate provides both phosphorus and calcium. Microminerals are usually supplied in a mineral premix.
Vitamins: Catalysts for Life
Vitamins are organic compounds required in small quantities but essential for normal bodily functions, growth, and reproduction. A deficiency in one or more vitamins can result in various diseases or syndromes.
Vitamins are categorized as fat-soluble (A, D, E, and K) and water-soluble (vitamin C and the B vitamins). Vitamin A supports the growth and development of epithelial tissue and reproduction. Vitamin D3 is required for normal growth, bone development, and eggshell formation. Vitamin E functions as an antioxidant. Vitamin K is essential for blood clot formation.
The B vitamins (B12, biotin, folacin, niacin, pantothenic acid, pyridoxine, riboflavin, and thiamin) are involved in numerous metabolic functions, including energy metabolism. While poultry can synthesize vitamin C, supplementation may be beneficial during periods of stress.
Some vitamins are produced by microorganisms in the digestive tract, and vitamin D can be synthesized when sunlight interacts with the bird’s skin. However, many essential vitamins must be obtained through the diet. Vitamin premixes are often used to compensate for fluctuating vitamin levels in feed ingredients and ensure adequate intake of all vitamins.
Conclusion: The Unrivaled Importance of Water
While carbohydrates, fats, proteins, minerals, and vitamins all play vital roles in poultry nutrition, water is arguably the single most important nutrient. Its involvement in digestion, nutrient transport, waste removal, and thermoregulation makes it indispensable for survival and productivity. Ensuring consistent access to clean, fresh water is the cornerstone of any successful poultry management strategy.
For more information:
- Poultry nutrition information for the small flock. Kenneth Wilson and Scott Beyer, Kansas State University.
- Nutrition for backyard chicken flocks. J.P. Blake, J.B. Hess, and K.S. Macklin, Auburn University.
