ANN 111: Principles of Animal Nutrition and Feed Technology (2+1)

ESTIMATION OF CRUDE PROTEIN (KJELDAHL METHOD)

Introduction

• Feeds contain nitrogen in the form of protein or non protein nitrogenous substances.
• In this estimation of crude protein, the nitrogen content of the feed is determined and multiplied by a factor 6.25 on an assumption that all proteins contain 16 per cent nitrogen. Thus as the estimated value does not truly reflect the true protein content of the feed, it is called as crude protein.