Rohfaser - behr Labor (EN)

Crude fiber

Good to know: Crude fiber is the portion of feed, which remains after treatment with acids, alkalies and solvents as indigestible constituent. The main component of crude fiber is cellulose.

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Crude fiber determination with behr: ISO, AOAC and AACC compatible

There are regulations in place worldwide for the determination of crude fiber content. Standard procedures are applied such as  ISO 6865:2000, ISO 5498:2000 (AOAC Official Method 962.09) AACC method 32-10.01, etc.
 
Crude fiber determination is an element of the classic Weende feed analysis. For crude fiber determination the sample is - if required degreased - treated successively with boiling acid and alkaline dilutions in the prescribed concentrations. Following filtration with a sintered glass filter, the sample is washed, dried, weight and incinerated at 475 … 500 °C. The weight loss during incineration corresponds to the crude fiber content of the sample.

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What are crude fibers

The term "crude fiber" originates from the animal feed industry and refers to substances that are not digested by animals. "Crude fibers" give a sum parameter of chemically partly very different substances. Mainly components of the plant cell wall, cellulose, hemicellulose and lignin.

Why crude fiber determination

A balanced proportion of crude fiber in feed is important, as it is important for healthy digestion on the one hand, but on the other hand it is also an energetically unusable part and thus increases the price of the feed.

Why different methods

Different animals have different digestive systems. Thus, ruminants (ruminantia) can degrade cellulose in contrast to non-ruminants (monogastric animals). Depending on the application, a differentiated analysis should be applied.

Different stocks of crude fiber and their determination

It is used here in

  • ADL - mainly lignins
  • ADF - mainly lignins and cellulose
  • NDF - mainly lignins, cellulose and hemicellulose

are differentiated.

Based on the different regulations, the different ingredients can be calculated as follows

  • Lignins Lignin= ADL
  • Cellulose = ADF-ADL
  • Hemicellulose = NDF -ADF
 

Analysis methods

All analyses are based on the fact that the feed crust is digested under temperature and the undigested substances are incinerated and weighed.

The difference lies in the lytic chemicals used.

  1. according to Weender, where the ADF content (cellulose and lignin) is determined.
  • DIN EN ISO 6865:2001-02: Feedstuff - Determination of crude fiber content - Process with intermediate filtration
  • ISO 5498:1981-04: "Agricultural food products; determination of crude fiber content; general method"
  • AOAC 962.09
  1. According to Soest, where the ADL (lignin) and the NDF content (lignin, cellulose, hemicellulose) are additionally determined, so that the cellulose and hemicellulose content can be calculated.
  • DIN EN ISO 13906:2008-11: Feedstuff - Determination of the content of acid-detergent fiber (ADF) and acid-detergent lignin (ADL)
  • AOAC 973.18
   

 

Rohfaser - Comfort Line (halbautomatisch)

Comfort Line (semiautomatic)

Instruments for crude fiber digestion that can be operated semi-automatically

Available product variants:
Rohfaser - Basic Line (manuell)

Basic Line (manually)

Manually operated instruments for crude fiber digestion

Available product variants: