Page 118 - Raw Diet References Book 2019

a ) Predictive Equations (NRC 2006a) for ME in ME in prepared pet foods for cats and dogs (dry and
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prepared foods for dogs and cats For calculation of wet) the following 4-step-calculation can be used:

1. Calculate GE

GE (kcal) = (5.7 x % protein) + (9.4 x % fat) + [4.1 x (% NFE + % crude fibre)]

GE (kJ) = (23.85 x % protein) + (39.33 x % fat) + [17.15 x (% NFE + % crude fibre)]

2. Calculate energy digestibility (%):

Dogs: % energy digestibility = 91.2 – (1.43 x % crude fibre in DM)

Cats: % energy digestibility = 87.9 – (0.88 x % crude fibre in DM)

3. Calculate digestible energy:

kcal DE = (kcal GE x energy digestibilty) / 100

kJ DE = (kJ GE x energy digestibilty) / 100

4. Convert into metabolizable energy:

Dogs: kcal ME = kcal DE – (1.04 x % protein)

kJ ME = kJ DE – (4.35 x % protein)

Cats: kcal ME = kcal DE – (0.77 x % protein)

kJ ME = kJ DE – (3.22 x % protein)

Note: In dog foods with crude fibre content above accurate estimate of ME compared to the modified
8 % in DM and a high percentage of fermentable NSP Atwater method in dry pet foods;
in the crude fibre fraction the predictive equation can • The modified Atwater method and the NRC
underestimate the energy density. equations provide an equally moderate accuracy of
Recent reviews (Calvez et al. 2012a; Calvez et al. ME estimation for wet foods for both dogs and cats.
2012b; Dobenecker 2015) comparing the accuracy The above-mentioned findings will be used for the
between the modified Atwater method and the development of a European Standard referencing
equations cited by the National Research Council the predictive equations described in a for the
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(NRC) versus measured ME have shown the following: calculation and declaration of the energy density in
• The equations cited by NRC provide a more prepared pet foods.

Publication May 2017 58/100