Testing your forage and feed is one of the most valuable steps you can take to make sure your cattle are meeting their nutritional needs. By collecting good samples, choosing the right tests, and understanding the results, you can save money, improve animal performance, and avoid unexpected problems.
The first step is making sure your sample represents what the cattle will eat. Always sample by “lot,” meaning hay or forage that comes from the same field and cutting. Never mix bales from different cuttings or pastures into one sample. Also consider timing, sampling right before feeding shows the most accurate nutrient value since it includes any storage losses. Use a hay probe or core sampler when possible and collect at least 20 cores from different bales in a lot. For chopped silage or baleage, take grab samples from several locations and mix them. Once collected, combine samples in a clean bucket, mix thoroughly, and seal in a heavy-duty plastic bag. For high moisture feed, freeze the sample until it’s shipped to the lab.
Clear records are just as important as a good sample. Label each bag with your name, lot ID, harvest date and forage type. On the lab paperwork, note any details about maturity, legume content or suspected issues like mold. Ship samples quickly, preferably early in the week. Use ice packs or freeze high moisture feeds like silage to keep it from spoiling.
When looking for a place to send samples, look for an accredited lab certified by the National Forage Testing Association (NFTA). At minimum, request tests for dry matter (DM), crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF). These values allow the lab to also calculate energy, like TDN. Optional tests like nitrates, minerals, or fiber digestibility are worth considering if you suspect specific issues or are feeding high-risk forages like sorghum or drought-stressed hay.
Understanding the Results
• Dry Matter (DM): Indicates how much actual feed remains after water is removed. Essential for balancing rations and preventing spoilage.
• Crude Protein (CP): Estimates protein content but can include non-protein nitrogen (like nitrates). Heat-damaged hay may show inflated CP, so some labs also report available CP.
• ADF and NDF: Fiber values that affect digestibility and intake. High ADF means lower energy; high NDF limits how much cattle will eat.
• Energy (TDN, NE): Energy values calculated from fiber. As ADF increases, energy drops. Meeting cows’ energy needs is often the biggest feeding challenge.
• Ash and Minerals: High ash often means dirt contamination, which dilutes feed value. Mineral panels can flag shortages or imbalances that may require supplementation.
• Indexes (RFV, RFQ): Useful shorthand for comparing hay quality, though best applied only within similar forage types.
The real value of forage testing comes when you compare lab results to your cattle’s requirements. For example, if a cow needs 1.4 pounds of protein daily but your hay only provides 0.9 pounds, you know to add a protein supplement. Conversely, if your hay is richer than expected, you can save money by cutting back on purchased feed. Matching different forages to the right class of cattle is also smart management. Reserve your highest quality hay for lactating or growing animals, while dry mature cows might be able to get by on lower-quality forage.
Alicia Boor is the Agriculture and Natural Resources agent with K-State Research and Extension – Cottonwood District. Contact her by email at aboor@ksu.edu or call 620-793-1910.
