Chapter 1

Question 1

What are the broad classifications of nutrients?

Answer 1

Water, protein, fat, carbohydrate, minerals, vitamins.

Question 2

What is the first step in proximate analysis to determine the water content of a feedstuff?

Answer 2

Drying.

Question 3

What alternative methods to drying can reduce damage to feed?

Answer 3

Freeze-drying or drying at lower temperatures (i.e., 55° C).

Question 4

What does ether extract (EE) represent in a feed sample?

Answer 4

The fat content.

Question 5

How is crude protein (CP) determined in feed analysis?

Answer 5

By the Kjeldahl method.

Question 6

What assumption is made when calculating protein content using the Kjeldahl method?

Answer 6

All protein is assumed to be 16% nitrogen (N).

Question 7

What does ash measure in feed analysis?

Answer 7

The total inorganic component, often interpreted as contamination.

Question 8

What is crude fiber (CF) an estimate of in a feed sample?

Answer 8

The cell wall constituents, including cellulose, hemicellulose, and lignin.

Question 9

What does nitrogen-free extract (NFE) estimate in a feed sample?

Answer 9

Water-soluble polysaccharides (sugars, starch).

Question 10

Who developed the improved methods of fiber analyses known as the detergent fiber system?

Answer 10

Van Soest.

Question 11

What does acid-detergent fiber (ADF) estimate in feed analysis?

Answer 11

Cellulose + lignin.

Question 12

What does neutral detergent fiber (NDF) estimate in feed analysis?

Answer 12

Cellulose + hemicellulose + lignin.

Question 13

How is hemicellulose estimated using the detergent fiber system?

Answer 13

By subtracting ADF from NDF (NDF - ADF).