Minutes of NIRS Consortium Nutrition Advisory Committee

Meeting Date: July 27, 2000

Meeting Place: Baltimore, MD in conjunction with ADSA Annual Meeting

Members Present: Jim Linn, Larry Chase, Michael Hutjens, Randy Shaver, Peter Robinson, David Mertens, and Paolo Berzaghi, and Neal Martin

NIRS Consortium Members and Consortium Sponsors: Don Sapienza, Marcia Endres, and Pat Hoffman

Prepared by: Neal Martin

Agenda For Baltimore Meeting

1) NIRS calibration of digestion kinetics parameters - RUP silages, hay, and green alfalfa and DDM calibration

We have several developments in the NIRS Consortium that merit this topic first. Paolo Berzaghi, NIRS and DFRC visiting scientist, has been working with Pat Hoffman and the Plant and Soil Analysis Lab at Marshfield as well as with David Combs. A new RUP calibration for hay is ready for use, the silage calibration will be updated and a green alfalfa equation for plant breeders will be developed this summer. The Plant and Soil Analysis Lab will be running Ruminal Degradable Tests to support our calibration efforts. However, labs using RUP for silage calibration are not happy because they are not getting enough use.

I am asking Paolo to lead us through a discussion of what the group has done to improve calibrations and most important obtain your support of a new package of tests the Consortium can launch (RUP silage, RUP hay and Ruminal degraded NDF leading to TDN predictions). For your review, I have attached the slides Dave Combs and Paolo have prepared which Paolo will discuss (TDN_RUP.ppt).

2) Development of definitions of forage testing terms. Attached is a file that Dave Mertens prepared that lists test terms used by commercial forage testing labs (Lab_Term.rtf). Also, Larry Case provided me with a list of terms with definitions that "Dairy One" has prepared. I will bring a hard copy along to be handed out. If any of you have other such materials, please bring enough copies for us all to review.

3) Discuss status of NIRS 'White Paper’. A rough draft of a 'White Paper’ will be provided at the meeting.

Meeting Decisions and Recommendations:

1) NIRS calibration of digestion kinetics parameters - RUP silages, hay, and green alfalfa and DDM calibration.

The main reason Laboratories are not receiving enough requests for the RUP test for silage is that the test use is diagnostic and not a necessary component of ration formulation programs. The requirement to treat the sample separate from routine forage tests by oven-dry rather than routine microwave drying method adds cost and incontinence. The case Paolo and Dave Combs proposed is that more than one test for availability of a nutrient in the rumen be made available RUP and Ruminally degradable NDF at maintenance. See slide Number 15 of power point file I emailed 7/21/00, identified as TDN_RUP1.ppt. Discussion centered on 2 issues: the time used to determine NDF degradability (24, 30 or 48-hours). It was my impression everyone agreed to using Digestible NDF at 48-hours because of a high probability that the new Dairy NRC will recommend such an in vitro test.

Paolo announced to the group that the new RUP calibration for hay is ready for release. This calibration does not require microwave drying. Also, Dan Undersander, Pat Hoffman, and Dave Combs are in the process of developing a License Agreement, which will allow offer labs a package of tests, i.e. RUP, Digestible Dry Matter,

Recommendation:

1. Offer a ruminally digestible NDF from in vitro analysis done at 48 hours. This is a universally developed and recognized in vitro method. We anticipate the new Dairy NRC will recommend a 48-hour in vitro test value.

2. Offer NEL at 4X maintenance. This will be calculated using Moe and Flat TDN calculation or one recommended by NRC from a value for Digestible Dry Matter derived from Combs in vitro Digestion Kinetics NIRS calibration. Combs's calibration is for hay and Haylage.

2) Development of definitions of forage testing terms.

The list of tests used by commercial forage testing labs in U S prepared by Mertens (file Lab_term.rtf) was discussed. Dave has listed the exact spelling for tests, which he has taken from forage test reports from labs, which participate in the Consortium and NFTA laboratory proficiency-testing program. Also, a list of terms with definitions used by Dairy One, provided by Larry Chase was distributed to be used as a basis for such a list prepared for Consortium Laboratories.

Recommendations:

1. Prepare definitions of tests that the Nutrition Advisory Committee will endorse to test forage crops.

2. Randy Shaver volunteered to give one of his summer student interns an assignment to assist Mertens with this project. The student will provide a list of tests with the number of times each test is used by given laboratory. Second, a draft of tests used currently used by Consortium Labs plus new tests being developed will be provided for review by this Committee.

3. NIRS Consortium Laboratories should be encouraged to place these test definitions on the back page of forage test result-sheets.

3) Discuss status of NIRS 'White Paper’.

Feedback provided from the group is to develop the 'White Paper' around the theme of how NIRS analysis of forages and feeds needs to be done for the best accuracy. Then include a basis or evidence of how labs within the Consortium meet those accuracy proficiency standards. Better yet use calibration validation statistics of Consortium Calibrations or Labs within the Consortium. Randy Shaver and Paolo Berzaghi will assist Don in the preparation of this document.

Recommendation:

1. Prepare a first draft for review by early October.