Submitted by: Liliane Silva, Clemson University Forages Specialist
Forage quality is commonly defined as the nutrient concentration and digestibility of forages. It is important to emphasize that in the technical literature, forage quality is defined by forage nutritive value and intake. The nutrient concentration of forages directly impacts individual animal performance (e.g., growth, milk production), while the total amount of forage produced determines the animal production per area.
The main factors affecting forage quality are plant species, management practices, and the environment. Generally, legumes are of higher quality than grasses due to less fiber and higher crude protein concentration in legumes. Incorporation of legumes into grass systems contributes to balance production and quality in the animal’s diet. Management practices, such as fertility levels and maturity also influence forage quality. Overly mature forage will have higher fiber fractions and a lower passage rate due to lower digestibility, reducing overall intake and compromising animal performance.
The storage of conserved forages is crucial to decreases losses in quality and quantity. Decreasing contact with soil, rainfall, wildlife and air (for high moisture sources, such as baleage) is crucial in supporting the quality of stored feed. Then, upon feeding, it is important to make sure the animal nutritional needs are met. Conducting a forage analysis is the first step, since it is the only way to determine the forage quality.
Collecting a forage sample for analysis
Most producers will request information on crude protein (CP) and total digestible nutrients (TDN) concentrations from supplements they purchase. Still, they will never analyze forage samples from pastures or hay that animals consume. To determine the nutrient concentration, a forage sample must be analyzed in the laboratory. For live plants (pasture), forage should be randomly collected throughout each field at the target stubble height recommended for grazing. Several sites should be collected and compiled into a bucket, mixed thoroughly, and a composite sample sent to the laboratory for analysis. It is a similar approach to soil sampling.
Hay and baleage should be sampled using a hay probe with a power drill to facilitate the process. Several bales should be tested to collect a representative forage sample. Bales should be sampled at the round size on round bales and the short side on square bales. On wrapped bales, after collecting the samples, use heavy-duty UV-resistant tape to cover each hole to prevent air and wildlife from entering the bales because this would lead to losses in quantity and quality. It is essential always to follow the recommendations from the laboratory for the size and storage of forage samples to be sent for analysis. Consult your local Extension agent if you have any questions on how or where to send collect forage samples.
In the Southeast region, producers can submit a hay or baleage sample to the Southeastern Hay Contest for a chance to win prizes. There are several entry categories, and the top three producers in each category are awarded prizes at the Sunbelt Expo in Moultrie, GA in October. For more information, click here: https://site.caes.uga.edu/sehaycontest/
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