Sector Poultry

How to balance the protein profile of your poultry diets

Protein is essential for the growth and development of young birds in poultry species. Just like the human body, animal bodies consist of trillions of cells, and every one of them contains protein. As the building blocks of life, proteins play a crucial role in the formation of muscles, feathers, organs, and other essential tissues. Unfortunately, in the body, most of these proteins have a life span of only two days or less, so dietary protein is needed for a steady supply of amino acids, the fundamental components of protein. Adequate feed protein intake ensures proper feathering, robust immune function, and optimal metabolic processes, laying the foundation for healthy adulthood and productive life cycles.

What are proteins?

Proteins are crucial components of cells and serve various essential functions such as healing, oxygen transport, immune defense, energy provision, and muscle development. They consist of long chains of amino acids bonded together, with each protein having a unique sequence and shape that determines its specific role, like acting as a muscle or enzyme. Think of amino acids as the letters of an alphabet, forming words (peptides), and ultimately creating the entire protein ‘language’.

Some amino acids can be produced by the body, while others, known as essential amino acids, must be obtained from the diet, like lysine and methionine. Different species and life stages have varying requirements for these amino acids due to their involvement in various bodily processes.

Enzymes, a type of protein, play a vital role in breaking down dietary proteins during digestion. The key enzyme involved in this process is protease, which breaks feed proteins into shorter peptide chains in the small intestine. Another enzyme, peptidase, then further breaks down these peptides into individual amino acids for absorption.

Figure 1: Breakdown of protein by protease and peptidase

Can birds get too much protein?

Although dietary protein is of high importance to to support the rapid growth, skeletal development, and overall health of young birds, too much protein protein intake can pose drawbacks:

  • First, protein is expensive. So undigested protein is a waste of money.
  • Moreover, a protein that is not digested and absorbed in the small intestines will make its way to the hindgut. In the hindgut, bacterial fermentation of the undigested protein releases ammonia that causes damage to the gut wall and reduces the colon’s ability to absorb water. Consequently, the feces will become wetter and contain higher ammonia levels. The presence of water and ammonia in the feces increases the incidence of footpad dermatitis and (through higher ammonia levels in the air) respiratory issues.
  • Additionally, hindgut fermentation can promote the growth of undesirable bacteria, such as Clostridium, potentially causing gut inflammation and leaky gut syndrome if left unchecked.

Reducing protein levels

Lowering dietary protein levels can improve footpad health and overall bird welfare by reducing wet litter and footpad lesions. It’s important to ensure that essential amino acid levels remain sufficient when decreasing protein content in the diet.

Figure 2: Liebig’s barrel shows how the first limiting amino acid determines the growth of the bird

As mentioned before, several amino acids are needed to synthesize protein and the amino acid requirement of each protein is different. When the appropriate amount of an amino acid is not available, it is the first limiting factor that deter¬mines the growth of the bird.

An easy visualization is Liebig’s barrel. In the image shown here, methionine is the limiting amino acid (Figure 2). Nowadays, there are synthetic amino acids that can help fulfill the need for amino acids while reducing dietary protein levels. If methionine is the limiting amino acid, we can add synthetic methionine until it is not the limiting factor anymore.

Similarly, as it is the next limiting factor, lysine will need to be added to further increase the water level in the barrel. There¬fore, to achieve a balanced protein profile, both lysine and methionine need to be added. In this way, similar levels of growth perfor¬mance and quality can be achieved even with lower crude protein levels.

Dietary protein: know your feed ingredients

Protein intake is essential for various metabolic functions, including immune support, digestion, and muscle development in poultry. Supplying birds with sufficient protein is crucial for optimal health, but it’s equally important to understand their specific dietary needs based on factors like breed, age, and environment. Additionally, the quality of feed components influences protein availability, as not all protein in the feed may be digestible by the bird (see Figure 3). Understanding the nutritional content of feed ingredients is therefore essential for providing birds with the best possible diet.

The exactness of protein formulation

Figure 3: Depending on the quality of the source, the amount of crude protein will be different from the actual digestible amino acids made available to the animal. By formulating on digestible amino acid ratios, you formulate on what is really used by the birds while also considering the difference in requirement per amino acid.


Providing poultry with the right amount of protein is vital for their growth, health, and well-being. Proteins serve as the foundation for various metabolic functions, such as muscle development, immune support, and digestion. However, too much protein can lead to waste and health issues like wet litter, footpad lesions, and gut inflammation. By reducing protein levels while ensuring essential amino acids are still present, overall bird health and welfare can improve. Through meticulous protein management and feed composition, production potential can be optimized while reducing the risk of diseases. At Earlyfeed we apply this knowledge and principles to our entire range of Galli products.

Your Earlyfeed expert
Stefan Alius
Product Manager Poultry

This contact was suggested based on the location you are browsing from. You can of course also consult our other contacts and locations here.

Do you want to get things right from the start?

Getting your rearing strategies right early in the production cycle, pays off in the long run.
Together, let’s give the youngest animals everything they need to perform well later in life.

Stay up-to-date

Would you like to be kept informed of our latest developments? Register here and stay up to date.