NDF + ADF 11

BY4055

Proximate analysis

method to estimate nutrient composition of feeds and forages

Moisture

water content of the feed

Ash

total mineral (inorganic) content after combustion

Crude protein (CP)

protein estimated from nitrogen content

Ether extract (EE)

crude fat content of the feed

Crude fibre (CF)

traditional fibre measure that underestimates total fibre

Organic matter

total weight minus ash

Nitrogen free extract (NFE)

soluble carbohydrates calculated by subtraction

Fibre

plant cell wall material affecting intake and digestibility

Cellulose

structural carbohydrate in plant cell walls

Hemicellulose

more digestible cell wall carbohydrate

Lignin

indigestible component limiting fibre digestibility

Fibre digestibility

decreases as lignin content increases

Fibre quality

determined by degree of lignification

Crude fibre (CF)

simple fibre measure that underestimates true fibre

Neutral detergent fibre (NDF)

total plant cell wall content

Acid detergent fibre (ADF)

cellulose and lignin fraction of fibre

NDF

hemicellulose + cellulose + lignin

ADF

cellulose + lignin

NDF − ADF

hemicellulose (and soluble cellulose)

NDF calculation

(W3 − (W1 × C1)) × 100 ÷ W2

ADF calculation

(W3 − (W1 × C1)) × 100 ÷ W2

ADL calculation

(W3 − (W1 × C1)) × 100 ÷ W2

W1

weight of empty filter bag

W2

sample weight

W3

bag weight after extraction

C1

blank bag correction factor

High NDF

reduced voluntary intake

High ADF

reduced digestibility

Nitrogen free extract (NFE)

estimate of soluble carbohydrates

NFE using CF

100 − CP − EE − Ash − CF

NFE using NDF

100 − CP − EE − Ash − NDF

pH

measure of acidity or alkalinity

Acidic solution

pH less than 7

Neutral solution

pH equal to 7

Alkaline solution

pH greater than 7