FEED and FORAGE SAMPLING

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FEED and FORAGE SAMPLING Powered By Docstoc
					 FORAGE ANALYSIS: “WHICH BOX DO I
         TICK?” and more

RON PIETT
AGRI-FOOD LABORATORIES
IMPORTANCE of FEED SAMPLING

The best analysis that you can receive begins
with the best sample that you can deliver.
FOR RATION FORMULATION
 – optimize animal performance
 – know quality of feed ingredients as starting
   point
 – determines supplement levels necessary
 – environmentally and economically unsound
   to overfeed-metabolic disorders, high P
– environmental growing conditions have
    pronounced impact on quality
–   many animal diets made up of >50%
    forages, most variable
–   animals can only use a portion of poor feed
•    For selling of feed
•   To determine presence of undesirable
    contaminants and toxins
     WHAT TO SAMPLE
all feeds consumed in diet either
individually or in a mix (sweet feed, TMR)
water (quality- mineral imbalance,
microbiological)
some feeds are more important to test than
others due to the inherent variability
grains less variable than forages
minerals can be more important sometimes
     WHEN TO SAMPLE
depends on time availability, equipment,
accessibility, type of feed
can be sampled as harvested or stored,
during storage, or just prior to or during
feed out
dry feed can be sampled any time -
depending on accessibility
wet forages should be allowed to stabilize
 once fermentation is complete (2-3 weeks)
   HOW OFTEN TO SAMPLE

depends on feed type, stability, storage facility,
variability of crop being sampled
if feed is purchased or “home grown”
mixed grain tested once or twice per year unless
purchased in small loads
hay sampled by the cutting, field, or load
field variability should be noted and marked
wet forages can change over time, i.e. moisture
when problems arise or performance changes
   ANALYSIS OPTIONS:
  NIR vs WET CHEMISTRY
Background of NIR
Energy between specific atoms
Location and intensity of bands determine
component values
Success of method dependant on factors
both NIR and chemistry related
Comparison of methods
FACTORS AFFECTING SUCCESS
          OF NIR
Type of bonds between atoms
Specificity and sensitivity of wavelengths
Reference population
Wet chemistry results: c.v. associated with
method
Reference method AOAC approved
           APPEAL of NIR

Speed of analysis
Economics
Cleanliness-no reagents
Environmentally friendly
Training necessary
Species specific?
“On the fly” calibrations
ANALYTICAL PACKAGES
Wet chemistry packages usable on any feed
type
Packages for very basic analysis to very
comprehensive analysis complete with
invitro and insitu components
More expensive due to time, personnel,
usable reagents and equipment
non-species specific
    ANALYTICAL PACKAGES

NIR packages exist for common forages
Limited by species specificity?
Less expensive
Combinations of wet chemistry and NIR for
particular end user results i.e. Dry cows,
OARDC energy equations, mineral
imbalance, DMI packages
    ANALYTICAL PACKAGES

Wet Chemistry:
– suitable for any feed, byproduct or blend of
  feeds
– typically contain Dm, Cp, and minerals
-packages denoted as Type I to V with different
  mineral package in each, Type IV contains
  ADF and energies
– TMR Excel for any feed, not specific to TMR’s
– Excel Plus for sol. and bypass protein
    ANALYTICAL PACKAGES

-NCPS (nonforages) is all wet chemistry
and provides all values necessary for Ohio
State energy equations or use in CNCPS,
(CPM Dairy)
Options available with any package
    ANALYTICAL PACKAGES

NIR
-packages all or part NIR
NIR20, NW40, NW41, Excel Dry Cow,
NCPS (forages) are available
Personal preference, software, or cost will
usually determine package selection but
cost should not be limiting factor
  ANALYSIS SELECTION
Keep in mind the purpose of the
feed….why am I including this in the
ration? Protein, energy, fibre
The tests selected should reflect the purpose
and source of the feed i.e. HM corn
(protein)? Distillers grain (NDF-Cp)
How important is a value with respect to the
overall composition of the feed i.e. fat in
haylage?
  ANALYSIS SELECTION
Wet chem packages, Type I to V usually
used for commodities that are protein
sources or for checking on mineral values in
any feed where a possible problem due to a
mineral imbalance may be suspected
Type IV was popular when all energy
calculations were based on ADF alone, need
regression equations, and fibre is important
  ANALYSIS SELECTION
Currently NDF has superceded ADF in
importance in ration programs
This has resulted in TMR Excel packages
gaining popularity for any feed or forage
analysis where wet chem. is required or
requested
To enhance energy calculations’ accuracy,
options may be required for important
components i.e. fat for soybeans, bakery
  ANALYSIS SELECTION
Excel Plus is especially useful to compare
soluble and rumen bypass protein in feeds
and forages
Limitations do exist in adapting laboratory
methods to imitate biological functions
This must be kept in mind when comparing
results of similar feeds that have undergone
different processing techniques
  ANALYSIS SELECTION
NCPS analysis is most comprehensive, providing
numbers necessary for the calculation of energy
using the Ohio State equations
Non forage samples are done all by wet chemistry
This should provide the best evaluation of energy
Move to replace NDF term with NDFd
  ANALYSIS SELECTION
NIR packages for forages are the most
popular
Contains fairly complete analysis for most
software programs
This will be the area of expansion and
development due to cost effectiveness
If it can be measured accurately it can be
adapted to NIR!?
  ANALYSIS SELECTION
NIR20 had been work horse of packages for
years but giving way to NW40
This trend is likely to continue with the
increased importance placed on mineral
values i.e. nutrient management
Increased interest in balancing based on
minor minerals will increase demand for
NW41 analysis esp. zinc
  ANALYSIS SELECTION
For corn silage, starch by NIR has been an
asset as huge variations in starch content
have been noticed
Selection of the Dry Cow package is self
explanatory. This package is not used
enough with respect to DCAD
Ohio State energy calculations are included
although default values are used for
components not analyzed
  ANALYSIS SELECTION
NCPS forages has same advantages as non
forage package
Note differences in reporting terms such as
ADF-Cp and lignin
Discourage using NIR package for grains,
as the population used to develop this
calibration was quite small
NEW HORIZONS IN FEED TESTING
       BACKGROUND

Historically, the evaluation of feed quality
has been based on the nutritional profile and
energy equations that determine TDN from
regression equations, calculated from ADF.
Inconsistent results have been found using
these equations, especially from samples
high in lignin, fat or ash. These equations
are also species specific.
Advances in nutrition and in computerized
software programs have enabled us to more
closely approximate component values and
the amount of usable protein and energy
supplied to the animal.
OARDC equations have enhanced the
evaluation of energy, NCPS and CPM
provide more dynamic programs
The mathematics associated with these
programs is the most comprehensive
available, but the numbers used in some of
the applications, are based on assumptions,
average values or practical extrapolations.
The rates of digestion of fibre, protein and
starch are most important in the
optimization of animal performance.
 EXCEL BASIC ANALYSIS
The Excel Basic Analysis       60
gives the nutritional
                               50
values associated with the
individual components of       40
the feed. Any information                               NDF
                               30
we derive from this                                     Cp
analysis depends on how        20
typical the feed is, with      10
respect to the specific feed
type. It does not indicate     0
                                    1   2   3   4   5
any dynamics of the feed.
   CONDENSED INVITRO
Many invitro analyses      60
have focussed on only      50
two points, the zero
                           40
point, as determined                                NDF
from the basic             30                       Cp
analysis, and a point      20
further in time (30 hr).   10
This results in a
                           0
profile as seen here.           1   2   3   4   5
      INVITRO ANALYSIS
Invitro analysis associated with the DMI package,
makes use of five time points for the
determination of the NDF digestibility profile, and
four time points for protein digestibility.
The rumen fluid is extracted from fistulated cows
in milk. Donations of fluid and mat are extracted
from several cows for each run.
DIGESTIBILITY DIFFERENCES

As indicated, hybrid, environment, soil fertility,
harvest and storage management, can influence the
dynamics of a feed, in particular, forages.
It is not obvious how a feed will digest from the
zero point data, but from the digestibility graphs,
one can ascertain a possible explanation for
performance inconsistencies
 FIRST CUT HAYLAGE DIFFERENCES

              60
              50
NDF % of DM




              40
                                                 NDF110
              30
                                                 NDF174
              20
              10
              0
                   1   2        3        4   5
                           TIME POINTS
                            Rates of Disappearance of NDF

                      100
NDF Disappearance %




                      80        Kd=6%/hr
                      60
                                                                      NDFd1
                                                     Kd=3%/hr
                      40                                              NDFd2

                      20
                       0
                            0        20         40          60   80
                                           Time Point hr.
     NDF DIGESTIBILITY
  of selected first cut forage
TYPE      D.M.   Cp%    NDF%   NDFd%
Baleage   37.0   19.9   51.3    61.0
Haylage   29.0   24.3   47.2    60.2
Baleage   45.0   13.4   56.9    63.4
Haylage   60.0   19.6   43.9    45.0
Haylage   46.7   19.9   44.0    49.6
       IN SITU STARCH
       DISAPPEARANCE
Similarly, looking at starch disappearance, in situ
techniques are used
Undried and unground samples are placed in
nylon bags and suspended in the rumen of a
fistulated cow
Any number of bags of a particular sample can be
used to represent a number of time points
The results indicate rate and extent of
disappearance
                   IN SITU CORN SILAGE STARCH

              45
              40
SATRCH % DM




              35                                SILAGE 1
              30                                SILAGE 2
              25
                                                SILAGE 3
              20
                                                SILAGE 4
              15
              10                                SILAGE 5
               5
               0
                   0      1                 2
                              TIME POINTS
       STARCH VARIABILITY
       of selected corn silages
DM     Cp%    ADF    NDF    Lignin Starch NFC

29.2   12.8   30.8   47.9   4.5   11.8   30.8

43.3   8.0    18.1   35.0   2.6   36.4   48.0

39.5   9.2    17.4   32.5   2.5   38.5   49.0

26.8   13.6   30.8   54.5   4.5   8.9    23.0
 Digestibility of Corn Silage
D.M.   NDF%   NDFd%   Starch%   Starchd
                                   %
38.9   41.3    47.2    34.1      79.0
39.5   49.5    57.4    21.5      82.9
32.4   50.0    66.4    20.5      99.0
35.2   32.8    29.9    32.2      91.4
32.8   40.1    45.6    27.7      96.1
                         NDF Disappearance for Corn Silage
NDF disappearance % of


                         60
                         50       Kd=5%/hr
                         40
         NDF




                         30               Kd=4.5%/hr                   NDFd1
                                                                       NDFd2
                         20               Both have lag time of
                                          2-5 hr
                         10
                          0
                              0      20              40           60
                                          Time hr.
   VOLATILE FATTY ACIDS
Products of fermentation, provide source of
energy for ruminants
Indicate quality of fermentation that has taken
place
Test include: pH (4.2-haylage, 3.6-silage)
          • Acidity (0.68-11.56)
          • Lactic, acetic, propionic, butyric,
            isobutyric acids
          • Ammonia
          • Dry matter
           VOLATILE FATTY ACIDS
Test         Haylage1   Haylage2   Haylage3
Moisture     69.6       76.0       82.1
pH           4.06       5.18       5.57
Ammonia      0.8        6.2        10.8
Acidity      2.78       3.12       2.09
Acetic       0.02       4.57       5.73
Propionic    0.01       0.8        0.72
Butyric      0.01       3.0        3.12
Isobutyric   0.01       0.23       0.18
Lactic       4.00       0.20       0.10

				
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