Skip to main content

Table 2 On reduced crude protein diets for broilers: consideration for the linear programming matrices.

From: Progress of amino acid nutrition for diet protein reduction in poultry



Ingredient matrix

 Soybean meal

Improved varieties: amino acid levels and digestibility, carbohydrate fraction adjustments, improved oil content, and ability to utilize full fat beans

 Insect meal

Increased industrialized production of insect meal resulting in decreased costs; improved amino acid digestibility

 Algae meal

Increased industrialized production of algae meal resulting in decreased costs; transition from salt water to fresh water systems with reduced climate impact

 Single-cell protein meal

Increased industrialized production of single-cell protein sources resulting in decreased costs; improved amino acid digestibility


Free base L-valine is being produced commercially and used in formulation. Its inclusion allows for reduced diet costs, decreased nitrogen excretion, and a mechanism to feed balanced branched-chain amino acids

L-glutamine and betaine

Research is necessary to assess if L-glutamine and/or betaine can aid intestinal integrity in birds fed low CP diets

 Feed-grade amino acids

Increased manufacturing of essential (e.g., beyond L-valine) and non-essential amino acids at low cost

 Feed-grade amino acid peptides

Increased manufacturing of di- and tri-peptides with good digestibility at low costs

 Feed-grade enzymes

Availability of feed-grade enzymes with affordable pricing and consistent efficacy have given nutritionists a tool to improve ingredient quality

 Increasing feed phases

Adding diet phases allows for closer meeting the birds’ need and minimizing excesses

 Sex separate feeding

As female broilers require an order of 10 to 15% less amino acid levels, separate or separate phased diets per sex can increase nitrogen efficiency

Nutrient matrix

 Protein level

Less dependence on diet protein and more on amino acid supply by formulating to non-essential amino acids

 Protein expression

Can converting crude protein to true protein aid in predicting a critical amino acid supply?

 Digestive dynamics

As CP decreases, more cereals enter diets with less dietary oil sources, and it is known that feed-grade amino acids interact with starch regarding digestion. Nutritionists should create ratios to limit rapid starch in low CP diets

 Ideal protein for digestible amino acids

Robust Lys needs must be assessed as modern broiler genetics continue to be improved and express dietary needs on a digestible basis


Threonine must continue to be assessed as antibiotic growth promoters are removed from diets, as well as the balance regarding glycine plus serine

 Branched-chain amino acids

Assess limiting needs singularly and together in practical low CP diets

 Phenylalanine + tyrosine

Assess limiting needs in low CP diets in and relation to the branched-chain amino acids


Assess needs in low CP diets for broilers using a pre-experimental adjustment period

 Electrolyte balance

Reduced protein results in less soybean meal and monitoring electrolyte balance from the potassium reduction is critical

 Non-essential amino acid levels

As protein continues to be reduced, using nutrient minimums for non-essential amino acids will be required to maintain a nitrogen pool