Introduction

A proper diet should provide animals with the nutrients they need to grow, maintain optimal health and support production. Nutritional requirements differ depending on the species of poultry, their life stage and the type of production.

Feed ingredients should be properly balanced to provide the nutrients that birds need at the appropriate levels. Ingredient availability and cost fluctuate frequently, so feed formulations can also be adapted as needs arise. Nutritionists must be able to balance the nutrient profiles of different ingredients with the nutritional requirements of the poultry they are feeding.

Nutrients

Nutrients provide animals with:

  • energy needed for growth and development
  • compounds needed for normal bodily functions

Macronutrients are those needed in large amounts, including:

  • water
  • carbohydrates
  • lipids
  • proteins and amino acids
  • macrominerals

Micronutrients, such as vitamins and trace minerals, are required in small amounts.

Essential nutrients cannot be synthesized by the animal and must be provided by feed to avoid any deficiencies. Nonessential nutrients can be derived from other molecules when necessary. Feeding for optimal health involves a combination of essential and nonessential nutrients.

Water

Consistent access to good quality water is important for poultry production. As the main component of blood, water:

  • maintains blood pressure
  • allows transportation of nutrients and wastes throughout the body
  • regulates body temperature
  • is used in many chemical reactions in the body

Losing access to water for just a few hours can impact egg production. In hot conditions, a lack of water increases the risk of heat stress in birds.

Energy

Energy is a crucial component of a bird’s diet. Poultry need sufficient energy to meet their needs and thrive in production. The energy concentration in the diet influences how much feed the birds will consume. If the feed is energy-dense, the birds will consume less of it, so it is important to balance nutrient levels and energy density to make sure birds receive adequate nutrition.

Carbohydrates are the main source of energy in poultry feed. However, lipids and proteins can also provide energy.

Carbohydrates

Carbohydrates include:

  • starches
  • sugars
  • fiber

Poultry digest starches and sugars well for energy, but not fiber.

Cereal grains are the primary source of carbohydrates in poultry diets, making up the bulk of their feed. Common grains used in poultry diets include:

  • corn
  • wheat
  • barley
  • oats

Lipids

Lipids, made up of fats and oils, are energy-dense, providing more than twice the energy per gram compared to carbohydrates. Lipids improve the palatability of the feed and reduce its dustiness.

Lipids are composed of fatty acids which determine their physical properties, such as being liquid or solid at room temperature. The only essential fatty acid for poultry is linoleic acid, commonly referred to as omega-6. It is advised to have a minimum of 1% linoleic acid in all poultry diets.

Poultry digest oils better than fats, but both can be used in poultry feed. Common lipid sources include:

  • corn oil
  • soy oil
  • canola oil
  • tallow
  • lard

Flaxseed is often included in feed for laying hens to produce omega-3-enriched eggs. Too much flaxseed can excessively increase the energy and fat content of the diet, increasing the risk of fatty liver disease in laying hens. Marine oils, such as those from fish and algae, can also be sources of omega-3 fatty acids.

Protein and amino acids

Proteins are broken down into amino acids during digestion, which are later used by the bird to create new proteins. These proteins and amino acids are important for growth, production, and maintenance of health.

Proteins consist of 20 amino acids linked together in a chain. The order of amino acids and interactions between them gives specific proteins their unique shapes and functions. In the body, proteins are used in every biological process, so it is important that poultry have access to the amino acids required for protein synthesis.

If the protein source in poultry diets does not provide sufficient amino acids, the diets can be fortified with free amino acids to meet the birds’ nutrient requirements.

There are 10 essential amino acids for poultry:

  • arginine
  • histidine
  • isoleucine
  • leucine
  • lysine
  • methionine
  • phenylalanine
  • threonine
  • tryptophan
  • valine

Cysteine and tyrosine are considered conditionally essential. They can be synthesized from methionine and phenylalanine, respectively, if there is enough in the diet. Otherwise, they must also be supplied in the poultry feed. Common synthetic amino acids available in the market include:

  • lysine
  • methionine
  • threonine
  • tryptophan
  • valine

Sources of protein and amino acids in poultry feed include:

  • soybean meal
  • corn gluten meal
  • canola meal
  • legumes (peas, faba beans)
  • meat meal
  • fish meal
  • synthetic amino acids

Younger birds have higher protein requirements as their organs are still developing. As birds age, their protein requirements decrease. For pullets and hens, the protein requirement goes back up when they begin to lay eggs.

Vitamins

Vitamins and minerals are necessary for metabolism and chemical reactions that keep the body functioning properly.

Fat-soluble vitamins can be stored in fat tissue, and excessive intake can lead to toxicity. Fat-soluble vitamins include:

  • Vitamin A
  • Vitamin D
  • Vitamin E
  • Vitamin K

Water-soluble vitamins can be removed from the body if there is an excess. Water soluble vitamins include:

  • Vitamin C
  • Vitamin B

Vitamin C is considered nonessential because it can be made by poultry when needed, although supplementation can provide added health benefits.

Minerals

Macrominerals are minerals that poultry need in large amounts. Examples of macrominerals include:

  • calcium
  • phosphorus
  • sodium
  • potassium
  • manganese
  • chlorine
  • sulfur

Calcium absorption is affected by the amount of phosphorus available in the feed. The ratio of calcium to available phosphorus must be carefully considered to meet poultry requirements. For most birds, a ratio of calcium to available phosphorus of 2:1 is recommended. For laying and breeding hens, the ratio ranges from 8.4:1 to 11:1 depending on the stage of their lay cycle.

Phosphorus in plant-based ingredients is largely incorporated into phytate, which is not well utilized by poultry. To improve phosphorus availability, a phytate-digesting enzyme called phytase can be added. It is important to consider the levels of available phosphorus in the feed and not total phosphorus.

Microminerals, also known as trace minerals, are required in much smaller amounts. Microminerals include:

  • copper
  • iodine
  • iron
  • manganese
  • selenium
  • zinc

Many vitamins and trace minerals that poultry require are supplied through a premix. A premix is a concentrated blend of vitamins and minerals that is added to the bulk of the feed, the carbohydrates and protein source, to supply essential micronutrients. Premixes can also contain:

  • supplementary amino acids
  • medication
  • enzymes
  • other additives

Choline

Choline is another essential nutrient for poultry. Previously categorized as a vitamin, it is no longer considered a vitamin as it does not fit the biological criteria, but it is still necessary for birds.

Ingredient considerations

Beyond nutrient profiles of ingredients and poultry nutrient requirements, there are many considerations nutritionists must make when formulating feed such as:

  • bioavailability or digestibility of nutrients in an ingredient
  • nutrient interactions and metabolism
  • mycotoxin concentration in ingredients
  • anti-nutritional factors in ingredients
  • availability and price of ingredients
  • length of time the feed will be stored
  • species, age, and production goals
  • processing method and particle size

Bioavailability refers to how much of a specific nutrient can be digested, absorbed and utilized from an ingredient. For example, phytate-bound phosphorus has lower bioavailability because poultry can't digest it effectively. To address this, a nutritionist might add phytase to the diet which helps break down the phytate and makes phosphorus more available.

Types of feed

A feed can be made into:

  • mash
  • pellets
  • crumble

with differences in:

  • homogeneity
  • heat treatment
  • ease of consumption for the birds

Pellets are typically fed to larger birds, while younger birds are often fed crumbled feed.

Pellet

Pelleted feed is made by treating mash with steam and pressure. It is passed through a ring die to form cylindrical shapes. The result is a homogenous pellet that is easy for the bird to consume without sorting.

Crumble

Crumble feed is pelleted feed that has been broken into smaller pieces. It has the benefits of pellets while being small enough for young birds to eat.

Mash

Mash feed does not require the specialized equipment or energy needed for pelleting. It is made by grinding the ingredients to a desired size and mixing them together. With mash feed, birds can pick out specific components, potentially leaving important nutrients uneaten.

Choosing feed

Providing appropriate nutrition is essential for bird health, food safety and achieving overall production goals. Whether you’re looking for a complete feed or a premix to add to your on-farm feed, consulting with a nutritionist can help you determine what works for you and your flock.