If you checked out last week’s blog post, you know evaluating your feed with a forage test is a vital part of establishing an effective feeding program. Make the most of your feed ingredients and ensure your livestock are getting the nutrition they need – submit a forage sample to a lab for analysis.
Getting the Sample
For best results, your forage sample should include hay from at least 20 bales of hay. Samples should be collected from the center of a bale with a forage sampler probe. Combine samples and send to lab as soon as possible, avoiding exposure to heat or sun.
Understanding the Results
Your sample’s lab summary report will contain a wealth of information about your feed. Here’s a list of common acronyms you’ll see on your forage test results:
- RFQ: The Relative Forage Quality (RFQ) combines many characteristics into a single, easy-to-compare number representing the overall quality and value of the hay. This is an especially useful statistic for buying and selling hay – the higher the RFQ, the better the forage.
- DMI: Dry Matter Intake (DMI) is an estimate of how much feed will be consumed by livestock. This estimate is based on the digestibility of the hay’s fiber.
- As-Sampled/As-Fed: These results reflect the nutritional value of forages at their original moisture content. Nutrient values will vary with moisture content, as they are diluted by the moisture. This statistic is used to calculate how many pounds of hay are needed in a ration.
- Dry-Matter: Forage samples with all moisture removed. The concentrated samples have 0% moisture, reflecting the true nutritional value of the forage. The dry matter statistics are used for comparing feed ingredients.
- Crude Protein: An estimate of the protein available in the feed, based on the forage’s nitrogen content. Protein is one of the most costly ration supplements; therefore high protein forages are desirable.
- NDF: Neutral Detergent Fiber (NDF) is used to estimate consumption or intake.
- ADF: Acid Detergent Fiber (ADF) predicts energy and digestibility of a forage.
- Energy: Vital for sustaining bodily systems and functions. Often measured as Total Digestible Nutrients (TDN) – a percentage that indicates energy available to livestock.
Inconsistent Results Between Labs
Some producers choose to check their lab’s accuracy by sending a forage sample to a second lab for analysis, comparing the results. This only works if both labs receive identical samples – which is often not the case.
If samples are not taken consistently and accurate, the producer will often get conflicting results in the two analysis reports. To ensure labs receive similar samples, producers should consider taking a large forage sample and splitting it in two, or by submitting the dried, ground sample from the first lab for analysis at a different facility. This should ensure more accurate and consistent results.
- “Listing of Hay Probes.” ForageTesting.org
- Mayo, Doug. “Understanding Your Forage Test Report.” Jackson County Extension.
- Putnam, D. and Orloff, S. “Proper Sampling Methods Improve Accuracy of Lab Testing.” University of California Cooperative Extension.