Read the current Progressive Forage digital edition

Four common mistakes for forage samples

Rebecca Kern for Progressive Forage Published on 31 March 2020
forage sampling

Working in a commercial agricultural-testing laboratory, I see all different types of feed and forage samples submitted in all kinds of ways. A silage sample might be sent to us in a large vet glove, while a corn grain might come in a coffee can, even when most labs provide sample bags for submission. Which brings me to the first of four common mistakes made when submitting forage samples to a commercial laboratory for testing.

1. Not sending the sample in a sealed container

It is imperative that moisture is not lost from the sample or accumulated during sample shipment to the lab. Ziplock bags are provided for sample submission by most laboratories. It is important to inspect the bag for holes and ensure it is sealed prior to shipment. This is imperative to preserve the moisture and dry matter of the sample. Moisture and dry matter are used to calculate all lab constituents from dry basis to as received. If the “as received” does not reflect the nutrient contents of the harvested forage, the result is incorrectly mixed final rations.

2. Not including contact information

If you are submitting a sample to a commercial laboratory, it is implied you would like to see a report upon completion of your sample’s analysis. Many people will mail samples to the lab without enough information. Commercial labs need your name and address to mail your results. If you want to receive your results as soon as possible, an email is also required. A phone number is also helpful in case laboratory personnel have questions about your sample during sample processing or would like to contact you to discuss your results. If it has been awhile since you put your sample in the mail, and your report is still pending, contact the lab as they may not have known where to send the results. If the rest of the information was clearly marked, the analysis is likely already completed and the lab is just waiting to determine where the report needs to be sent.

3. Not indicating which analyses are being requested

If submitting a feed or forage sample to the laboratory, it is key to let them know what constituents you need to see on your report. It is important to include paperwork or clearly write on the sample bag which tests to run. If you fail to indicate what the lab needs to do, they will likely assume a basic package, which may or may not include the nutrients you wanted to see on your report. If you aren’t sure which analysis to request, do a little research; visit the laboratory’s website and see if they offer a packaged analysis that makes sense for your forage-sampling goals. If you are still unsure which test to mark, call the lab and ask what they suggest. If you receive a report that doesn’t have the nutrients you needed for your decision making, call the lab in a timely fashion. Most labs retain a portion of the sample for a short period of time and can add analysis. Do not settle for an unsatisfactory report.

4. Not including a description of what the forage is

Especially if you are planning to have your forage analyzed by near-infrared spectroscopy (NIRS), it is important to tell the lab what kind of forage you are submitting. Commercial laboratories have different prediction equations for different types of forage. They know which species are included in which equations. To be sure your sample is analyzed using the correct equations based on a sample library, which includes that forage species, it is key to let the lab know that information. If the forage species is omitted from the sample information, laboratory personnel will make an educated guess about the forage species that may be correct, but if they are wrong, it could affect the NIRS prediction equations applied to the sample and/or the energy calculations used for reporting.

In conclusion, proper sample handling is key, and the more information you can give the lab the better. When submitting forage samples to commercial laboratories for nutritional analysis:

  1. Ship samples in a Ziplock bag.
  2. Include your full name, address, email and phone number.
  3. Indicate what analysis you want the lab to run.
  4. Clearly identify the type of forage sample you are submitting.

If you have questions, contact the lab. Following these steps will avoid confusion and ensure accurate results are reported. Clear communication with the lab is the key to a smooth sampling process. Most labs welcome questions that will ensure properly submitted samples.  end mark

PHOTO: Collect forages in air-tight containers to ensure an accurate sample. Staff photo.

Rebecca Kern
  • Rebecca Kern

  • Animal Scientist
  • Ward Laboratories Inc
  • Email Rebecca Kern