What are beta-mannans?

β-mannans are likely costing you money in unnecessary feed costs:

They’re almost certainly in your feed, so understanding more about these compounds is the first step to stopping them sapping your productivity, and reducing their wider environmental impact…


β-mannans = non-starch polysaccharide (NSP) fibres


Naturally occurring non-nutritive feed compounds

  • They cannot be broken down in the gut and detract from, rather than adding to the nutritional value of the feed
β-mannans are found in many common vegetable feed ingredients:

  • Palm kernel meal: 7.24%
  • Soya hulls: 6.67%
  • Soybean meal: 0.67%
  • Sunflower meal: 0.60%
  • DDGS: 0.57%
  • Oats: 0.31%
β-mannans are resistant to common feed processing procedures, such as pelleting and extrusion.

The problem with β-mannans

β-mannans cause a natural, but costly series of events within an animal, called a Feed-Induced Immune Response (FIIR):

1. The animals’ innate immune system misrecognises β-mannans as a potentially disease-causing pathogen and mounts a response to protect itself against the perceived threat.

The molecular pattern of β-mannans is similar to some microorganisms

2. This natural, but unnecessary immune response

  • uses up energy
  • causes inflammation
  • negatively affects Intestinal Integrity
  • reduces nutrient absorption
  • negatively affects energy metabolism

3. Animals need to be fed more to compensate for these losses.

Even small amounts of β-mannans (just 0.2%) trigger this response

β-mannans cause a feed induced immune response (FIIR)

Reduces nutrient digestion

Diverts energy away from growth / production

Negatively impacts on gut health

Increases feed costs


1. Daskiran, M., Teeter, R., Fodge, D. and Hsiao, H. 2004. “An Evaluation of Endo-ß-D-mannanase (Hemicell) Effects on Broiler Performance and Energy Use in Diets Varying in ß-mannan Content.” Poultry Sci. 83: 662-668.