Chapter 3 - feed evaluation

Question 1

Proximate feed analysis system

Answer 1

Water vs dm (ash, CF, CP, [EE ether extract], NFE [Nitrogen free extract])

Question 2

Problems with proximate analysis

Answer 2

CF fractions lowe than actual true fiber value
lignin is counted as NFE even if its not digestible in GI tract
under estimates digestiility of nonfiber carbs, overestimates digestibility of fiber,
compounds errors of DM, CF, CP, EE and ash analysis

Question 3

Detergen fiber system (van soest)

Answer 3

Breaks into NDS, NDF, and ADF

Question 4

Relationship between feed composition and digestibility of alfalfa hay

Answer 4

as lignin, ADF and NDF increase, digestibility decreases

Question 5

other components in feed evaluation

Answer 5

Atomic absorption procedure

Inductively coupled plasma analyizers

Amino Acids

Vitamins

Question 6

NIR

Answer 6

Near infrared reflectance: predicts chemical composition in feeds
Advantages: fast, cheap
disadvantages: precision dependent on calibration data, not the actual chemical composition

Question 7

Feed particle size

Answer 7

ruminant, rumination activity. Digestibility, particularly of cereals. intake in birds (cant eat grains that are too large). uniformity separation of ingrediencts

Question 8

Importance of particle size

Answer 8

too small - affects rumen ph, low milk fat test, subclinical acidosis, founder
Too large - diet sorting and reduced feed consumption

Question 9

Hay and Silage sampling

Answer 9

sample silages from several locations in the silo

use a core sampling device with hay