How to Accurately Determine the Energy Value in Feed Using a Bomb Calorimeter?

Why is the energy content of feed so critical in animal nutrition?
Energy is the core of ration formulation, and an incorrect calculation can increase costs while reducing efficiency. For this reason, accurately determining the true energy value in laboratory analyses directly affects the reliability of everything from production to R&D.

So, how can we determine the true energy value in feed with the highest accuracy?
This is where the bomb calorimeter comes into play — the most precise method used in feed analysis for measuring energy.

What Is a Bomb Calorimeter and Why Is It Used in Feed Analysis?

A bomb calorimeter is a device that measures the amount of heat released when a sample is completely combusted in an oxygen-rich environment.
This measurement directly yields the feed’s gross energy (GE) value.

It is highly valuable in feed analysis because it provides the most sensitive and direct method for determining gross energy.

How Is Gross Energy Measured?

When a feed sample is combusted completely under oxygen, the heat released represents its gross energy value.

Main analysis steps:

• The sample is weighed with high precision.
• It is placed into the combustion chamber (bomb).
• The chamber is pressurized with pure oxygen.
• The sample is ignited and fully combusted in a controlled manner.
• The temperature change in the surrounding water jacket is monitored with high resolution.

The resulting heat value is the sample's gross energy, expressed in cal/g, kcal/kg, or MJ/kg.

Is Gross Energy Alone Sufficient?

Where Does the Atwater Method Come In?

Energy in feed cannot be determined solely by combustion results, because animals do not digest feed completely. Therefore, the measured gross energy does not represent the actual usable energy.

To estimate digestible energy, the Atwater method is applied.

What Are Atwater Factors and Why Are They Still Used?

Atwater factors form the theoretical basis for calculating metabolizable energy (ME) by accounting for the digestibility of protein, fat, and carbohydrates.

They remain widely used because they provide a consistent and scientifically accepted foundation for evaluating the usable portion of feed energy.

How Are the Bomb Calorimeter and Atwater Method Used Together?

You may ask:
“If I already have bomb calorimeter results, why do I need the Atwater Method?”

• Bomb calorimeter → Measures gross energy (GE)
• Atwater Method → Estimates the digestible (usable) portion of this energy

Atwater factors consider digestibility and provide the amount of energy the animal can truly utilize.

When bomb calorimeter data and Atwater calculations are used together, you achieve double-validated, scientifically robust results.

New Approaches in Determining Usable Feed Energy

Recently, advanced modeling techniques that go beyond traditional methods have gained attention, especially in the research and R&D fields.

These approaches aim to more accurately reveal how efficiently animals use the energy they consume.

Bomb calorimetry provides high-precision energy values. After obtaining these results, a linear model can be created based on the relationship between consumed nutrients and excreted waste. This makes it possible to determine:

• The theoretical amount of waste that should be produced
• The amount of energy actually utilized by the body
• Digestive efficiency and bioavailability

This methodology provides valuable scientific insights by quantifying energy losses.

If you’re curious about how this approach can be integrated into your laboratory workflow, we would be happy to help identify the best solution.

Which Sectors Use Bomb Calorimeters for Feed Analysis?

• Feed mills — to ensure accurate quality control
• R&D laboratories — to test new feed formulations
• Universities — for scientific research and energy studies

Energy value is the most critical quality parameter in feed, and bomb calorimetry is the gold standard in this field.

What Is the Most Reliable Way to Measure Feed Energy?

Accurate energy values come from accurate instrumentation.

• The bomb calorimeter is the most reliable method for feed energy measurement.
• The Atwater Method complements this by connecting energy determination to animal nutrition science.

Used together, they place feed quality, ration planning, and animal performance on a solid scientific foundation.

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Debye Technic bomb calorimeters, developed in Türkiye, deliver the precision and stability required by international research standards.

If you would like more information about our products or wish to collaborate with our R&D team, feel free to contact us.

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