Winter is just around the corner, and that means it’s time to round up hay to get through the cold, long months. Whether you bale your own or purchase it from a neighbor, knowing the nutritional value of your forage supply is crucial to getting the most out of your feedstuffs.
I’ll admit, it’s not too often we send in a forage test to round up information on the winter hay we feed to our cattle. However, after reading “Understanding Your Forage Test Report,” by Doug Mayo, University of Florida Extension livestock and forages agent, it’s probably a practice we should implement on our operation.
Mayo reminds producers that because hay is highly variable from year-to-year and field-to-field, we shouldn’t guess on the nutritional value. Weather, fertility, growing and harvest conditions, and variety and age at harvest, are all factors that can make a huge difference in the nutritional value of the hay crop. So, to get a better idea of what you’re feeding to your herd, a forage sample can provide the needed information.
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After receiving a summary report, the next challenge is to understand it. Mayo lists six important factors in a forage report. Here are the six and his recommendations for getting the most out of a forage test:
1. Relative Forage Quality (RFQ)
“RFQ is an index, much like EPDs for cattle, that combines a number of important quality characteristics of forages to provide a single number to use for comparisons,” explains Mayo. RFQ predicts the fiber digestibility and animal intake of harvested crops to provide a single number to use for comparisons. RFQ is most useful for marketing or purchasing hay, as it serves as a simple guide of quality, but it isn’t the most useful to guide supplement purchasing decisions.
2. Dry Matter Intake (DMI)
“DMI is an estimate of how much an animal will consume, based on the digestibility of the fiber in the hay. This is a calculated value that provides an estimate of the amount of hay each animal will consume each day,” says Mayo.
3. As-Sampled vs. Dry-Matter
“The moisture content of forages is never constant,” adds Mayo. “To compare quality, you always want to use the dry matter (DM) column. If you were actually mixing a feed, you have to use the as-fed information. Since hay is normally fed free-choice, it is most useful to work with the DM information to select the correct supplement, and be able to compare forage samples with varying moisture content.”
4. Crude Protein
“Crude Protein (CP) is based on the nitrogen content of the feed. This is why fertilization with nitrogen fertilizer does greatly enhance the protein levels of hay. Legumes produce their own nitrogen fertilizer through bacteria on their roots, and generally have even higher protein levels than grasses. Protein is one of the nutrients for livestock growth and performance, but it is simply a matter of providing what the animal needs. Proteins levels in hay below 7% can drastically reduce intake,” he says.
“Fiber is a key measurement of digestibility,” Mayo says. “The more mature, or older the forage, the higher the fiber content. Neutral Detergent Fiber (NDF) is the total fiber component of a forage used to estimate intake, or daily consumption. As the NDF percentage increases, intake declines. Acid Detergent Fiber (ADF) is the level of indigestible fiber that can’t be used by the animal. ADF is used to develop an estimate of nutrient availability.”
“Energy is the nutrient that keeps an animal’s systems working, and is vital for all of the body functions. Total Digestible Nutrients (TDN) is the value most often used to evaluate the energy available for ruminant animals for selecting supplements. The greater the value, the more energy-dense the feed. TDN levels below 50% can reduce animal intake. The other energy measures are more commonly used for more precise feedlot and dairy ration formulations,” he says.
Mayo offers a real-world example comparing three different hay crops off various fields, as well as how to test the hay, how to improve the forage quality, and how to best utilize the forage test. You can read the rest of his article here.
Do you test your forage quality each year? If so, how do you use the information to ration the winter forage supply for your herd? Do you offer free-choice hay? Do you grind, use bale feeders or add it into feed? How do you feed different classes of cows? Share your experiences in the comments section below.
The opinions of Amanda Radke are not necessarily those of Beefmagazine.com or the Penton Farm Progress Group.
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