ME( kcal/kg) = 10[(3.5 x CP) + (8.5 x CF) + (3.5 x NFE)]
where: ME = metabolizable energy
CP = % crude protein "as fed"
CF = % crude fat "as fed"
NFE = % nitrogen-free extract (carbohydrate) "as fed"
and the percentages of CP and CF are the arithmetic averages from proximate analyses of at least four production batches of the product; and the NFE is calculated as the difference between 100 and the sum of CP, CF, and the percentages of crude fiber, moisture, and ash (determined in the same manner as CP and CF); or,
N.M. Admin. Code § 21.18.3.26