Overview
ISO 6865:2000 - Animal feeding stuffs: Determination of crude fibre content (method with intermediate filtration) specifies a laboratory method to determine the crude fibre (cellulose) content of animal feed, cereals and pulses using an intermediate filtration step. The standard describes both a manual and a semi-automatic procedure and is applicable to samples with crude fibre greater than 10 g/kg. For feeds at or below 10 g/kg, ISO 6541 is recommended.
Key topics and technical requirements
- Scope and applicability
- Designed for animal feeding stuffs, cereals and pulses with crude fibre > 10 g/kg.
- Both manual and semi‑automatic workflows are defined.
- Analytical principle
- Sequential boiling in dilute sulfuric acid followed by potassium hydroxide (alkaline) digestion.
- Intermediate filtration separates residues between acid and alkaline steps; residue is dried, weighed, then ashed; mass loss on ashing = crude fibre.
- Reagents and key parameters
- Specified reagents include HCl, H2SO4, KOH, acetone, light petroleum and a filter aid (e.g., calcined sea sand or Celite®).
- Example parameters provided: test portion ≈ 1 g, boiling times 30 ± 1 min, drying at 130 °C, ashing at about 500 ± 25 °C.
- Apparatus and consumables
- Filter crucibles with fused sintered plates (pore size 40–100 µm), muffle furnace, drying oven, cold‑extraction device, and appropriate balances.
- Quality control
- Blank determinations and careful handling of filter aids and crucibles to avoid contamination or loss of sintered plates are required.
Practical applications and users
ISO 6865:2000 is used by:
- Feed analysis laboratories performing routine nutritional profiling and quality control
- Feed manufacturers verifying ingredient and product specifications
- Regulatory and compliance bodies assessing labelling claims or standards conformance
- Research labs studying feed composition, digestibility or formulation effects
Practical benefits:
- Provides a standardized, reproducible method for crude fibre quantification
- Supports feed formulation, nutritional labelling, and comparative studies across labs
- Semi‑automatic option increases throughput for high‑volume testing
Related standards
- ISO 6541 - Alternative crude fibre method for feeds with ≤10 g/kg crude fibre
- ISO 6498 - Preparation of test samples for animal feeding stuffs
- ISO 3696 - Water for analytical laboratory use (reagent water quality)
Keywords: ISO 6865:2000, crude fibre, animal feeding stuffs, intermediate filtration, crude fiber determination, feed analysis, acid and alkaline digestion, semi‑automatic method.