Transcript dvt1084-lecture 2 -proximate analysis-jan2011

M. WAN ZAHARI
DVT 1084- UMK
4/10/2015
1
Elements and Atomic Weight
Name
Symbol
Atomic
Wt
Name
Symbol
Atomic
Wt
Carbon
C
12
Magnesium
Mg
243.3
Hydrogen
H
1
Sodium
Na
23
Oxygen
O
16
Chlorine
C1
35.
Phosphorus
P
31
Cobalt
Co
59
Potassium
K
39
Copper
Cu
63.5
Iodine
I
127
Flurine
F
19
Nitrogen
N
14
Manganese
Mn
55
Sulfur
S
32
Zinc
Zn
65.4
Calcium
Ca
40
Molybdenum
Mo
96
Iron
Fe
55.8
Selenium
Se
79
Many different feed nutrients are currently recognized, and
new ones are still being found. Those currently
recognized are as follows:
 A. Carbohydrate:
 Contains C, H, and O, with H and O in the
same proportion as in water. They consist
largely of hexosans. These are made up of
hexose or 6-carbon atom molecules.
 1. Monosaccharides e.g glucose, fructose,
galactose
 2. Disaccharides e.g. sucrose, maltose
 3. Polysaccharides e.g. starch, glycogen,
cellulose, lignin
4/10/2015
3
Many different feed nutrients are currently recognized, and
new ones are still being found. Those currently
recognized are as follows:
 Fats:

Contain C, H and O with more C and H in
proportion to the O than with carbohydrates.
Fats contain 2.25 times as much energy per kg
as do carbohydrates.
 1. Saturated fat e.g stearic, palmatic
 2. Unsaturated fat e.g Oleic, linolenic,
arachidonic
4/10/2015
4
Many different feed nutrients are currently recognized, and
new ones are still being found. Those currently
recognized are as follows:





C. Protein:
Always contain C, H, O, N and sometimes Fe, P,
and/or S.
The only macronutrient which contains N
Feed proteins on the average contain 16% N.
Formed by various combinations of amino
acids of which there are some 25+ to be found
in proteins. Amino act as organic acids which
carry the amino group (NH2).
4/10/2015
5
Continuation…..
 D. Minerals: Of the 20 elements that function in animal nutrition, C,
H, O & N are regarded as non- mineral elements
 16 are mineral elements: 7 Macro minerals are Ca, P, K, Na, S, Cl &
Mg and 9 Micro minerals are Fe, I, Cu, Co, F, Mn, Zn, Mo and Se.
 E. Vitamins: Organic substances required by animals in very small
amounts for regulating various body processes. They all contain C,
H, O and several contain N & mineral elements
 F. Water: Contain H & O. Water is found in all feed (ranging from
10% to 80%). Besides serving as nutrient and other important body
functions, it is very important factor in feed processing & storage
&feed value
4/10/2015
6
Continuation…..
 D. Minerals:
 Of the 20 elements that function in animal
nutrition, C, H, O & N are regarded as nonmineral elements
 16 are mineral elements: 7 Macro minerals
are Ca, P, K, Na, S, Cl & Mg and 9 Micro
minerals are Fe, I, Cu, Co, F, Mn, Zn, Mo
and Se.
4/10/2015
7
Continuation…..
. Vitamins:
 Organic substances required by
animals in very small amounts for
regulating various body processes.
 They all contain C, H, O and several
contain N & mineral elements
 E
4/10/2015
8
Continuation…..
Water:
 Contain H & O.
 Water is found in all feed (ranging
from 10% to 80%).
 Besides serving as nutrient and other
important body functions, it is very
important factor in feed processing &
storage &feed value
 F.
4/10/2015
9
SUMMARY OF THE VARIOUS FUNCTIONS WHICH
THE DIFFERENT NUTRIENTS MAY SERVE
BASIC FUNCTION
ACCESSORY FUNCTION
As a Structural
Material for Body
Building and
Maintenance
As Energy for
Heat
Production,
Work, and Fat
Deposition
As or for the
Formation of
a Body
Regulator
As a Source of Nutrients for
Milk (or Egg Production)
Protein
Yes
Yes
Certain
Amino acids
Yes
Carbohydrates
Only as fat
formed from
carbohydrates
enters into
makeup of
cellular growth
Yes
Yes
Yes
Fats
Only as fat enters
into makeup of
cellular growth
Yes
Certain
Fatty acids
Yes
Minerals
Yes
No
Yes
Yes
Vitamins
No
No
Yes
Yes
Water
Yes
No
Yes
Yes
4/10/2015
10
Proximate Analysis of Feedstuffs
A system for approximating the value of a feed or
material for feeding purposes, without actually
using the feed in feeding trial, was developed at
the Weende Experiment Station in Germany over
100 years ago.
It based on the separation of feed components
into groups or fractions in accordance with their
feeding value.
The various fractions are:
Water
Crude protein
Crude fat or ether extract
4/10/2015
Crude fiber
Nitrogen-free extract
Mineral matter or ash
11
Proximate Analysis of Feedstuffs
Following proper procedures in obtaining and preparing a
sample is essential for an accurate analysis on given lot of
feed.
1.
Procedures to determine the various fractions:
Water- oven dry : Loss of wt during drying  100 = % water
Wt of sample after drying
Wt of sample after drying  100 = % DM
Wt of sample before drying
100 - %DM = water
4/10/2015
12
2. Crude protein (CP)
Kjeldahl methods-determine the amount of
ammonia nitrogen (N)
3. Crude fat (EE)
Includes all of that portion of a feed soluble in
water. Crude fat is commonly referred to as ether
extract. Extract the sample with ether in a Soxhlet
extractor
.
4/10/2015
13
4. Crude fiber (CF):
This fraction was designed to include those
materials in a feed which are low digestibility.
Included hare are cellulose, certain hemicelluloses,
and some of the lignin, if present. Some of the
lignin, however, may be included in the nitrogenfree extract.
- dry sample, extract sample with ether, boil sample
with dilute sulfuric acid, filter, boil in dilute sodium
hydroxide then filter, dry the residue and weigh, ash the
sample
Wt of CF
 100 = % CF
Wt of original sample
14
5.
Mineral matter or ash:
Ash in a furnace (600 °C)
4/10/2015
15
6. Nitrogen-free extract: (NFE)
Commonly referred to as NFE. Includes mostly sugars
and starches, and some of the more soluble
hemicelluloses, and some of the more soluble lignin.
Since this fraction was designed to include the more
digestible carbohydrates, any lignin which may come
out here will to distort the meaningfulness of the NFE
figure as lignin is essentially indigestible.
NFE is determined by difference-that is, all those
fraction discussed above are added together and
subtracted from 100.
4/10/2015
16
As follows:
% water
% crude protein
% crude fat
% crude fiber
% mineral matter
-----------------------------------------------------100 – Total = % NFE
4/10/2015
17
7.
Expressing compositions:
A. In percent (%). This simply say that a
feed contains so many parts (grams,
milligrams, micrograms, etc.) of a
particular feed component per 100 parts
of the overall feed.
4/10/2015
18
B. In parts per million (ppm)
This simply says that a feed contains so
many parts (g, mg, mcg, etc.) of a particular
feed component per1,000,000 parts of the
overall feed.
4/10/2015
19
C.
In mg per kilograms (mg/kg).
This says a feed contains so many mg of
some component per kilogram of the
overall feed. Since a kilogram is equal to
1,000,000 mg, then “mg per kilogram” is
the same “mg per million mg” or “parts
per million”.
4/10/2015
20
The composition of feeds may be
expressed on any one or more of three
dry matter bases.
 A. As fed: Sometimes referred to as wet
or fresh basis. On this basis dry matter
of different feeds may range from 0% to
100%.
4/10/2015
21
Air-dry:
May be actual or an “assumed dry
matter content” basis. The latter is
usually 90%.
This basis is useful for comparing
the composition of feeds having
different moisture content.
Most feeds, but not all, are fed in an
air-dry state.
 B.
4/10/2015
22
C. Oven-dry:
Based on a moisture-free or 100%
DM state.
Also useful for comparing feeds of
different moisture contents.
4/10/2015
23
Why Test Feeds?
 Nutrient concentration can vary considerably in feeds,
especially forages
 Used feed tests to target specific feeds to different
livestock
 Feed test can help establish the RM value of a feed
 Use feed test to help determine what feedstuffs to buy for
feed processing activities
4/10/2015
24
What causes nutrient concentration
to vary?
 Plant species and variety-protein, starch,
fiber and toxins varies among varieties
 Maturity-as forage plants mature, fiber
concentration increases, concentration
of DE & NE
 Leafiness-leaves contain more CP & DE,
harvest & storage conditions that save
leaves result more CP and energy
4/10/2015
25
What feeds should be analyzed?
 Analyze all feedstuffs that influence ration cost or animal
performance. Important when potential differences
between estimated nutrient composition and actual
composition are great
 Forages: nutrient composition varies greatly
 Feed grains: seasonal & geographical differences-may
influence future purchases
 By-products: vary considerably in nutrient & moisture
content
 Always test non-traditional feedstuffs
4/10/2015
26
What causes nutrient concentration
to vary?
 Harvest-good management techniques ↑
nutritive values
 Storage-moisture content within specific
range
 Environment-temperature, sunlight, soil
moisture & fertility, diseases, weeds,
insects
4/10/2015
27
Methods of Feed Testing
 Physical: sight, smell, touch…., stage of maturity, foreign
materials, best, color-provide limited information
 Chemical-reliable & accurate predictions of animal
performance
 Near infrared reflectance (NIR) spectroscopy
 In vivo and in vitro
4/10/2015
28
What analyses should be made?
 Nutrients of primary concern: Ruminant (CP, DE or TDN,
Ca, P), Monogastric (CP, amino acids, ME, CF, Ca, P)
 Always compare cost of analysis to cost of supplement
 Analysis for moisture, protein & energy are most
important
 Sampling is the key to accurate feed analysis
4/10/2015
29