Overview

This calculation method was proposed in the 1980s based on measured pet food data and is officially adopted by AAFCO. When no feeding trial or direct measurement is available, AAFCO allows energy values for label purposes to be calculated using this method.

It is a practical, experience-based approach that reflects the average digestibility of typical commercial pet foods, making it simple and convenient to use. However, depending on the actual digestibility of a specific formula, the result may under- or overestimate true energy—so interpretation should be made with care.

Modified Atwater (3.5/8.5/3.5) ME Calculator

Species
NFE = 100 − (CP + Fat + CF + Ash + Moisture).
Modified Atwater directly estimates ME using 3.5/8.5/3.5 factors.
- kcal/kg
Modified Atwater / Dog (as-fed)
Dry matter (DM %)
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ME (kcal/kg DM)
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Protein contribution (kcal/kg)
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Fat contribution (kcal/kg)
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Carbohydrate contribution (kcal/kg)
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CP_DM (%)
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Fat_DM (%)
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CF_DM (%)
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NFE_DM (%)
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Factors: CP=3.5, Fat=8.5, NFE=3.5 (kcal/g, as-fed). There is no species-specific difference.
Modified Atwaterの詳細記事
ペットフードのカロリー計算式とMEの実務的理解と応用