Proximate Principle Calculated by Difference

Correct Answer: NFE (Nitrogen-Free Extract)

NFE is the ONLY proximate principle never directly analysed. Formula:

NFE% = 100 − (CP% + EE% + CF% + Ash%)

What NFE Represents

Mainly easily digestible carbohydrates — monosaccharides and disaccharides (glucose, fructose, sucrose, lactose, maltose). It is the primary energy source in most feeds.

Limitation

NFE is not chemically defined — includes all components not accounted for by other fractions, including measurement errors.