Proximate / Weende System Analysis of Feeds & Fodder-Significance and Limitations

1. Proximate Analysis of
Feeds & Fodder
Dr. Pankaj Kumar Singh
Assistant Professor
Department of Animal Nutrition
Bihar Animal Sciences University
Patna, Bihar, India, PIN-800014
E-mail: vetpank@gmail.com

2. PROXIMATE ANALYSIS
Weende System of Feed Analysis
Origin
• Weende Experimental Station, Germany 1865
• By Wilhelm Henneberg & Friedrich Stohmann
• Chemical analysis of feed & fodder

3. COMPONENTS
• Water or Moisture
• Crude Protein (CP)
• Ether Extract (EE)
• Crude Fiber (CF)
• Nitrogen Free extractives (NFE)
• Ash

7. Proximate Principles

15. MAJOR COMPONENTS
PROCEDURE FRACTION COMPONENTS
Drying (100±20o) Moisture Water, other Volatile
compounds
Ignite
(500-600o)
Ash Mineral Elements
Kjeldhal Digestion CP Protein, A.A., NPN
Ether Extraction EE Fats, Oils. Waxes
Boiling with Acid &
Alkali
CF Cellulose, Lignin
Remainder NFE Starch, Sugar

17. LIMITATIONS OF PROXIMATE ANALYSIS (Harris 1970)
Components Supposed
to contain
Contains Missing Excess
Water Water Volatile Fatty Acids
Decomposed Sugars
None Volatile Fatty Acids,
Decomposed Sugars
CF Fibrous
Matter
Cellulose,
Parts of Lignin
Hemicellulose,
Part of lignin,
Acid Insoluble
Ash
None
NFE Soluble
Carbohydra
tes
Soluble CHO
Hemicellulose,
Part of Lignin,
Acid Insoluble Ash
None Hemicellulose,
Lignin,
Acid Insoluble Ash
Ether
Extract
Crude Fat
(Fats, Oils.
Fatty
Acids)
Free Fats, Oils,
Fatty Acids,
Chlorophyll, Sterols,
Anthocyanin,
Carotenoids, Resins,
Volatile oils, Lecithin
Cholesterol, Alkali
Substances
Protein bound
lipids,
Fatty Acids
formed Soaps
Chlorophyll, Sterol,
Anthocyanin,
Carotenoids, Volatile
Oils Resins Lecithin,
Cholesterol,
Alkali Substances

18. MERITS
• It forms the basis for
• Description of feed composition tables
• Purchasing feeds
• Ration formulation
• various equations for energy estimations
• It is the starting point for specific analysis.
• Provides Ist hand information about the
potentiality of the feed to fulfil the required
nutrient.

19. Contd…
• Used for analysis of feeds, faeces, urine body
fluids
• No substitute till today except for fiber
component.
• Referred by Nutritionist, Chemist, Physiologists,
Bacteriologists, Dietatitian, Food Processors etc.
• Handy to handle.
• The process is simple and economic.

20. DEMERITS
• Broad categorization of carbohydrates, CF, NFE, EE & CP
• No indication of kind of mineral elements.
• It does not includes vitamin.
• Traditional conversion factor (6.25) is too large for most of
the wild vegetation. (Conklin-Brittain,1999)
• Values are approximate one and without actually using in
feeding trials.
• The partitioning of CF & NFE as poorly and highly digestible
respectively is questionable (Crampton & Maynard ,1937)
• The CF method severely underestimates the total plant cell
wall content of a feed. (Vansoest, 1994)

21. Contd…
• CF-considered as indigestible-non nutritive residue.
(Banerjee 1978)
• CF doesn’t account for some of the hemicellulose and
lignin components. (Schroeder , 1994)
• The residue of alkali-acid digestion is not truly
indigestible portion of feed rather is composed of
cellulose and variable portion of non cellulogic
polysaccharides and lignin. (Jung , 1997)
• The digestibility of carbohydrates does not follow its
partitioning into CF & NFE with any marked certainty,
especially for roughages. (Morrison, 1987)

22. • The CF of forages may be as well digested as the protein
(Newlander and Jones, 1932; Mitchell and Hamilton,1933 ; Morrison, 1937).
• NFE includes pentosans, other polusacharides, soluble
lignins thus over estimates. (Banerjee 1978)
• If EE contains large percentage of plant waxes, essential
oils, resins etc., it has little value.
• CP values give no indication if heat damage has occurred
which may alter protein availability.
(Schroeder , 1994)
• The ash content is not true representative of the
inorganic material in the feed.
Contd…

23. Thanking you
“Don’t let schooling interfere with your
education”
Mark Twain