How Do DDGS & Enzymes Affect Hen Rations?

Research Summary

Dried distillers grains with solubles (DDGS) provide a great source of digestible amino acids and energy to poultry diets. However, DDGS contain fiber which birds cannot digest well due to their lack of intestinal enzymes. As a result, commercial poultry producers often add exogenous enzymes to diets in order to improve digestion.

Research from Zagazig University in Egypt investigated how including an exogenous enzyme would affect performance when poultry received increasing amounts of DDGS. Results from this study show that feeding DDGS up to 12% of the diet did not negatively affect bird performance. The research also demonstrated how DDGS and exogenous enzymes can improve egg yolk color.


As a very general classification, fiber consists of a matrix of cellulose, lignin, and hemicellulose chains (Figure 1) all interwoven together. More specifically, these chains contain individual sugars and groups of sugars such as non-starch polysaccharides (NSPs).

In order to utilize these sugars, animals need to break down the sugars or polysaccharides into individual units using specific enzymes. Ruminants rely on bacteria in the rumen to break down fiber. Monogastric animals have minimal gut bacteria and limited enzyme activity. As a result, they do not degrade fiber as well as ruminants. Poultry and swine producers can partially overcome this limitation by providing a source of exogenous enzymes in the diet.

Figure 1. Structure of fiber with cellulose, lignin, and hemicellulose represented (Alonso et al., 2012)


In order to investigate how providing exogenous enzymes would affect laying hens fed DDGS, Abd El-Hack and coworkers fed laying hens one of eight diets in a 2 × 4 factorial arrangement. Treatments included diets with or without enzyme and either 0, 6, 12, or 18% DDGS. The researchers measured performance of the birds in addition to egg quality characteristics.


Including up to 12% DDGS in the diet did not affect the majority of performance measures. Egg mass (Figure 2) did not differ until researchers included 18% DDGS in the diet. Additionally, most performance measures did not change with the inclusion of enzyme.

Figure 2. Egg mass of hens fed DDGS with or without en-zymes (Abd El-Hack, 2019)

*These results are not a guarantee of nutritional value, as laboratory results are influenced by factors beyond the control of POET Nutrition.