Crude Fibre Calculator

Calculate crude fibre percentage in feed samples using gravimetric analysis with pre-ashing and post-ashing weights

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Weight of silica crucible with contents after acid/alkali treatment

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Weight of silica crucible with contents after muffle furnace ashing

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Original weight of the sample being analyzed

Update results automatically when inputs change

Results

Crude Fibre Percentage

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Fibre Weight

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Ash Weight

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Frequently Asked Questions

What is crude fibre in feed analysis?

Crude fibre is the portion of plant material in feeds that is indigestible by monogastric animals. It represents the structural carbohydrates like cellulose and lignin after acid and alkali digestion treatment.

How is the crude fibre percentage calculated?

The calculation uses the formula: (Weight before ashing - Weight after ashing) × 100 / Sample weight. This determines the organic matter lost during ashing as a percentage of the original sample.

Why do we ash the sample after acid-alkali treatment?

Ashing in a muffle furnace removes all organic matter, leaving only mineral ash. The weight difference before and after ashing represents the crude fibre content.

What temperature is used for ashing in crude fibre analysis?

Samples are typically ashed at 550-600°C in a muffle furnace for 3-4 hours to ensure complete combustion of organic matter while preserving mineral content.

What does a high crude fibre percentage indicate?

High crude fibre content indicates more indigestible plant material, which can reduce feed digestibility and energy value but may be beneficial for ruminant animals' digestive health.

How accurate should the weighing be for crude fibre analysis?

Weighing should be accurate to at least 0.001g (1mg) for reliable results, as small weight differences significantly impact the final percentage calculation.

What is the typical crude fibre range in different feeds?

Cereal grains typically contain 2-12% crude fibre, while forages like hay can contain 25-40%. Concentrates usually have lower fibre content than roughages.

Can this method be used for human food analysis?

Yes, this gravimetric method can be applied to analyze crude fibre in human foods, though dietary fibre analysis methods are more commonly used for nutritional labeling.

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