Savannah Valley District

Proper Hay Sampling Techniques

Written by Livestock and Forages Agents – Nicole Correa, Sallie Thompson, Marion Barnes, Travis Mitchell and Hillary Pope

With the fall weather starting to peek through, it is essential to start considering making hay purchases for the winter season. With all the options available, how does one choose? There are multiple grass and legume options, bales come in square or round bales, and hay colors and smells are associated with hay. To determine your operation needs, you must first determine your goals for the winter season and then test the hay you are buying to ensure that it fits those needs. The only way to properly test for nutritional qualities is to have a hay sample collected, and the sample process must be done correctly.

When testing hay, you should consider a visual assessment and a forage analysis to ensure you are purchasing high-quality hay. For a visual assessment, consider the stage of maturity, color, leafiness, foreign material, odor, and overall condition of the hay. When gathering samples for a forage analysis, follow these sampling techniques: sample each batch or cutting separately, collect 10-20 core samples from small bales or 3-4 core samples from large bales for one sample.1. The hay probe needs to be inserted at least 12-18 inches for a proper core sample. You should analyze for moisture, protein, and energy.2

Walz, 2017
Smith, 2020


It is crucial that you are sampling bales horizontally or against the grain, ensuring that you are sampling through multiple layers. This will ensure that your sample is a comprehensive example of each bale.

Below, you will find a table of the typical nutrient content of different types of hay. Although it is listed for horses instead of cattle, that does not change the nutrient levels. What can change your nutrient levels is the days of maturity before cutting, the drying process prior to baling, how that hay is stored, and whether fertilizer was applied during the growing season. Although it is typical to see Bermudagrass fall into that 6-11% protein, it can be lower than that depending on those factors listed above. This can also mean a significant variation of what you think you are feeding versus what the animals are actually consuming.4

Source: Dairy One, Feed Composition Laboratory

Total Digestible Nutrients are important to measure when looking at the relationship it has with digestible energy and can often be calculated based on ADF or acid detergent fibers. TDN is calculated by taking the sum of digestible protein, fiber, fats, and carbohydrates and is useful when cows are eating a diet mainly of forage. The higher your TDN value, the more energy-dense the forage is.4

Relative Forage Quality is another indicator of how the hay will affect your herd. Relative Forage Quality is the measurement of Total Digestible Nutrients (TDN) multiplied by Dry Matter Intake (DMI) divided by 1.23. This will tell you the forage quality ranking based on their relative nutritional value. Pair the RFQ value for the forage with the livestock that needs more nutrients. The chart below explains which classes of animals need a higher quality forage.5

Figure 4. The Relative Forage Quality (RFQ) range that are suitable to various livestock classes. Adapted from Undersander et al., 2011

Forage sampling is a way to ensure that your animals’ nutritional requirements are being met. Hay sampling tests for specific amounts of energy, protein, fiber, and other supplements that are necessary to maintain livestock function. All animals require specific amounts of nutrients just to function and be healthy. They also will require much more if they are production or performance animals and if they are growing from one stage to another. Even different livestock animals will require different amounts of nutrients due to their size and how their bodies absorb those nutrients. If proper nutrition is not achieved, then there can be a loss of body condition and ability to perform. Resulting in poor herd health and loss of profit.

The table below shows the TDN and CP levels needed for each animal class and stage of life. Compare the table nutrient requirements and your forage sample results to determine if your cattle are receiving adequate nutrients. If the hay does not meet the minimum nutrient requirements for the animal class and stage of life, then you must supplement with feed to reach the required amount of nutrients.

Sources Utilized:

  1. Submitting Feed & Forage Samples for Analysis. Clemson University
  2. Berger A. Test, Don’t Guess-Sampling and testing hay. UNL Beef. University of Nebraska-Lincoln. 2017 October.
  3. Teutsch C. Knowing What You Are Feeding: Hay Sampling 101. Ohio Beef Cattle Letter. The Ohio State University. 2020 October.
  4. Warren K. Selecting Hay for Your Horse. Equine Sciences. University of Florida.
  5. Hancock D. Using Relative Forage Quality to Categorize Hay. University of Georgia Extension.
  6. Dr. Lemus R. Hay Testing and Understanding Forage Quality. Mississippi State University Extension

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