What is hemicellulose?
High digestible fibres which allow to:
- Guarantee rations by providing fibres of quality
- Improve horse digestive comfort
Hemicellulose sources: beet pulps, wheat bran, wheat straw, corn cobs, soya bean hulls, maize bran, oats husk, spelt wheat husk, grass hay, ground wheat…(to be scientifically evaluated in diets. That’s the role of the formulation team among horse feed manufacturers).
Hemicellulose is calculated according to the measurement given by Van Soest and al., 1991, that is to say difference between NDF and ADF contents. It represents parietal fractions under arabinose polymers, xylose, glucose, fructose, mannose and galactose forms.
NDF: Neutral Detergent Fibre: collection of parietal carbohydrates, apart from pectic substances, gums and mucilages (solubles fibres).
ADF: Acid Detergent Fibre: lignocellulose (cellulose and lignine).
NDF - ADF = Hemicellulose
We must make the difference between soluble fibres and non-soluble fibres:
- Soluble fibres are represented by pectic substances (beet pulps, wheat bran, citrus fruits, apple pomace…), gums and muciliages (flax seeds) and a part of hemicellulose.
These soluble fibres have gelifying or viscogenous properties which influence satiety, digestion rapidity, and metabolic control of glycaemia, insulinoma and cholesterol.
- Non soluble fibres are mainly made of real cellulose, this last one becoming impregnated during ageing of plants with lignin, cutin, suberin…last ones having a negative effect on digestion because it is a more polymerized and lignified cellulose then less digestible.
Fibres have a ballast effect which is essential for digestive hygiene by preventing digestive troubles (diarrhoeas, indigestions, dysmicrobism), and their consequences: colic, laminitis…
- mechanical effect of food fibres has beneficial impact on:
- intestinal motricity
- boosting of amylase pancreatic secretion
- acceleration of tract decreasing therefore risks of caecolic dysmicrobism
- moisture increase, dung consistency and shape
- energy supply
- intestinal pressure decrease
The more digestible fibres are, the more high energetic interest they have and the more secured they are for digestive tract.
Minimum supply of total daily crude fibre (CF) for horses must range between 15 and 18 %, but it is more relevant to take into account total fibre supply (NDF) and lignocellulose (ADF) and with the difference to quantify supply of feed hemicellulose.