The economic perspective of Enzyme Matrix Values in Poultry Nutrition

Commercial enzymes (such as phytase, xylanase, Beta-glucanase, lipase, protease, and amylase) are used in poultry diets to increase nutrient digestibility, degrade antinutrients, liberate minerals, improve feed efficiency, reduce feed cost, and minimize the environmental footprint of nutrition by reducing the excreted phosphorus and nitrogen. When the price of feed ingredients increases, the use of enzymes in the diet becomes more profitable, providing a significant return on investment.

Each commercial enzyme has associated with its specific matrix values for nutrient(s). The nutrient matrix values for enzymes indicate the amount of a nutrient that could be released when the enzyme is added to a diet. Enzymes are used at low levels in the poultry diets, but they can have substantial effects on releasing the nutrients. For example, if an enzyme’s inclusion rate is 100 grams per ton (0.01%) and its matrix value of energy is 1000,000 kcal/kg, it will increase dietary energy by 100 kcal/kg. This value of 100 kcal/kg savings is known as the matrix value for the inclusion rate of the enzyme. As a result, the inclusion of the enzyme allows the nutritionist to reduce the target dietary energy by 100 kcals, which will reduce diet costs.

Using an enzyme in the feed will be profitable if the savings exceed the cost of the enzyme. Now, let’s do an economic evaluation of an enzyme price and calculate the maximum price you should pay per kg of an enzyme. Let’s imagine the price of a pre-lay diet decreased by 12 $/ton after adding an enzyme (for example, phytase) to the diet. If the inclusion rate of the enzyme is 100 grams per ton (0.01%), the maximum price for this enzyme should be 120 $/kg. However, the reduction in diet cost due to using the enzyme could be different for various nutritional phases. For example, using an enzyme can reduce a pre-lay diet cost by 12 $/ton, but this reduction in a layer diet could be 14 $/ton, which would increase the maximum price for the enzyme to 140 $/kg. Nutritionists should consider the diet cost difference between diets with and without an enzyme to evaluate the economic value of the enzyme.

As we discussed in a previous article ,the digestion and nutrient absorption ability of young chicks are low. Adding enzymes in the pre-starter and starter diet will increase nutrient digestibility and displace part of the fat in the diets by releasing more energy from other energy ingredients. As there is a limitation in using fats in starter diets (maximum up to 1% depending on the fat source), partial displacement of dietary fat with enzymes will be beneficial for digestion and absorption efficacy.

Considerations about using enzyme matrix values 

The response of poultry to an enzyme is dose-dependent and often follows a non-linear (for example, a log-linear) curve. This can cause incompatibility issues with the linear programming feed formulation system, as seen in the least cost feed formulation method. A non-linear formulation method, like those offered by Adifo Software (Bestmix), can resolve this issue.

Matrix values should be used cautiously as they might not always be accurate. Different factors such as birds’ age, dietary antinutrients, disease, and environmental conditions can affect the efficacy of enzymes in diets. Another concern in using these values is related to enzyme additivity issues. Nutritionists must be careful when reviewing the total matrix applied to any enzyme mixture. It is unclear whether the nutrient delivery by one enzyme is additive with the nutrient delivery of a second or third one. Feed enzyme suppliers must ensure that their recommendations about matrix values keep pace with nutritionists’ and producers’ growing demand for accuracy and precision.


Barletta, A. 2010. Enzymes in farm animal nutrition, M. R. Bedford and G. G. Partridge (eds.) Pages 1–11 in Enzymes in Farm Animal Nutrition, 2nd ed. CABI Publishing, Oxfordshire, UK.

Bedford, M. R. 2018. The evolution and application of enzymes in the animal feed industry: the role of data interpretation. Br. Poult. Sci. 59:486–493.

Bedford, M. R., and A. J. Cowieson. 2020. Matrix values for exogenous enzymes and their application in the real world. J. Appl. Poult. Res. 29:15–22.

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Research Associate at Poultry Innovation Partnership | + posts

2 Responses

  1. great insight on enzymes

    what is the consequence of adding more than 1 % fat/oil in the starter diets
    am using vegetable oil/flax

  2. Due to low digestibility of fat during the early life, the extra dietary fat will leave the gut undigested, which is waste of money. However, if your multienzyme contains lipase enzyme, you can add a bit more fat as the lipase will help with fat digestion. In addition, you will need to make sure that you are providing enough emulsifier to help with fat digestion and absorption.