To: Consortium Membership
From: Patty Laskowski
Date: April 17, 2001
Summary
/ Decisions
I. What We Saw/ Highlights:
A. Diagnostics, Standardization, Check Cell Program important in unifying our
network, in catching problems, and in improving output.
B. Particle size and variation in grinding process is an important factor in output
variation.
C. The Consortium website www.uwex.edu/ces/forage/NIRS/home-page.htm
can be a good tool to promote the organization and disseminate information.
D. Local Calibration is a possible move for the future. For now, Global
Calibration updates for the network are important.
E. We have an opportunity as a network to support the use of biological tests.
We have the capacity to create and use NIR equations that are supported by
biological data. We can also support biological research, carried out by
research organizations, that aims to quantify the nutrient availability of feeds
and forages. For example, prediction of in vivo digestibility by laboratory or
NIRS has had promising results. USDFRC wants to be a leader in
determining biological nutrient availability, determining digestibility and
digestion rate, and improving rapid methods of analysis such as NIRS. Our
organization, the NIRS Consortium, can lead the industry to nutritive value
decisions based on science (cutting edge).
F. In the Combs equations released Fall of 2000, the following parameters were
reported:
DNDF48 (%DM) = Degraded NDF after 48 h of in vitro incubation
in rumen fluid
DNDF3M (%DM) = Degraded NDF calculated measuring
degradation over time
NEL3M = 0.0245 ´ TDNmaint (%) – 0.12
DNDF30 (%DM) = Degraded NDF after 30 h of in vitro
fermentation
Proposed changes to the equations include:
NDFd48 = Single time point estimate of in vitro NDF degradability
(% of NDF)
NDFd30 = Degraded NDF after 30 h of in vitro fermentation
(% of NDF)
NDFd(kinetic) = Degraded NDF calculated measuring degradation
over time. 1-X maintenance intake (% of NDF)
TDN 1-X calculated by substituting NDFd48 or NDFd(kinetic) into
summative equation
G. The NRC Dairy 2001 contains many revisions over the 1989 version. Jim Linn
recommends listing the TDN1´ calculation on laboratory analysis reports.
This parameter is calculated from other laboratory-measured parameters
including tdNFC, tdCP, tdEE, and tdNDF.
H. Jim Linn also recommends reporting the following on feed analysis reports:
Fiber- NDF, ADF and Lignin
Protein- CP, ADIN, NDIN, and Sol-CP
Fat
Ash
Minerals- macro
Digestibility measures
NDF- 48 h in vitro
Protein - in situ
I. Corn silage is becoming increasingly important in diary nutrition. Laboratory
analysis to report components of nutrition equations for MILK2000 are also
important. Many NIR calibrations for these components already exist, but
work needs to continue on IVNDFd.
II. What We Will Get:
A. New ISI check cells have been distributed and invoices sent to labs.
B. Standardization of instruments has been completed for 17 out of 21 labs or
locations to be standardized.
C. Diagnostics continue with email reporting but web-based reporting will begin
to be developed.
D. A new forage check cell will be packed after the new soybean check cell has
been installed and is working properly. Each lab’s old check cell will be sent
to Paolo and filled with a new forage check.
E. Updates (see above proposed changes) to the Combs equations and a final
document on “How to Use” will be completed.
F. Documents for reference on grinding procedure will be distributed.
G. Documents for reference on recommended reporting method will be
distributed.
III. Activities We are Taking on:
A. Website Diagnostics
B. Combs Update
C. Corn Silage NDFd Equation Development
D. Check Cells- New ISI & New Forage Cells
E. Corn Silage Standardization
F. Review Effect of Grinding Procedure/ Particle Size
G. Additions/Changes to Website
H. Update Existing Calibrations
-Dry Matter
-Hay
I. Support Some Level of Standardization of Reporting
J. Promotion of Combs digestibility/Hoffman RUP package
IV. What You Will Be Asked To Do:
A. Send diagnostics weekly. First continue by email form and then on web as
this is developed.
B. Those who would like to receive an NDFd equation for Corn Silage will send
spectra and selected samples to Paolo.
C. Send your old check cell to Paolo to make new forage check cells.
D. Send spectra and selected samples to Paolo to develop a corn silage
standardization set.
E. Follow grinding protocol and send requested samples for grind/ particle size
evaluation.
F. Make suggestions about the Consortium website.
G. Those who would like to receive calibration updates on existing equations
will send spectra and selected samples to Paolo.
H. Provide feedback in a dialogue concerning standardization of reporting.
V. What To Do Now:
We are starting with these activities:
A. Send or continue to send diagnostics weekly
by email form.
B. Install the new check cell, once your lab
has been standardized, get the
installation approved by Paolo, and then
send your old check cell to Paolo.
C. View the Consortium website:
www.uwex.edu/ces/forage/NIRS/home-page.htm
and suggest any
updates, additions, or changes.
D. Review documents on grinding/particle size
and reporting for future
discussion and possible activity.
E. Participate in NDFd corn silage calibration
development discussions, if
interested in this equation.
F. Collect and file documents and information
in the last section of your
3-ring notebook received at the annual
meeting.