If You’ve Never Tested Forages, This is the Year to Start
Unusual weather patterns prompt concern forages may not meet nutrient requirements.
September 3, 2024
Winter forages may need to be supplemented with protein or minerals. That may be especially true this year, as many parts of the country had unusual weather conditions — either too wet or too dry to allow an ideal harvest. The only way to really determine the nutrient quality of forage is to have it analyzed.
Janna Block, a beef nutritionist with Hubbard Feeds, says fall is a good time to take hay samples.
“This gives producers a chance to evaluate hay inventory and determine which hay to feed to which group of cattle,” says Block, who was formerly a livestock systems specialist with North Dakota State University (NDSU). “They need a minimum of 7% protein in the diet. Below that, microbial efficiency in the rumen declines.”
At levels below 7% protein, the forage doesn’t provide enough protein to feed the microbes that ferment and digest forage.
At levels below 7% protein, the forage doesn’t provide enough protein to “feed” the microbes that ferment and digest forage, she explains. Digestion slows, and a cow can’t get adequate nutrients from what she’s eating. She can’t eat enough to sustain herself and loses weight.
A diet of forage that’s only 7% protein (and 50% TDN, or total digestible nutrients) might work for a dry cow that is mid-gestation, but it will be inadequate for cows in late gestation.
“They need forages that are at least 55% to 58% TDN and 8% to 9% protein for fetal growth and preparation for lactation,” she says, noting that condition of the cow plays a role. “If you are trying to feed a thin cow to pick up in body condition, she will need more nutrient-dense feed.”
Cows in late gestation or early lactation will have the highest nutrient requirements, needing approximately 60% TDN and 11% protein, she says. “Evaluate your forages and match them with various production groups. First-calf heifers have higher requirements for growth as well as trying to support a fetus and then produce milk. They need your highest-quality forages.”
Block recommends a hay inventory based on number of bales in each lot of hay, with a lot consisting of all the hay (same species) harvested off the same field under the same conditions within a 48-hour period.
Warren Rusche, assistant professor and South Dakota State University Extension feedlot specialist, demonstrates how to take a hay sample. [Photo courtesy Heather Smith Thomas.]
“We recommend sampling each lot,” Block says, admitting that might be a large number of samples for some. “Some people might just sample what they think is their worst hay so they know what the bottom level is, but we can’t put together a nutrition program without feed analyses to be able to target when you’d want to feed certain forages, or might need a supplement.”
Often ranchers just feed 35 pounds (lb.) of dry matter and a couple pounds of protein supplement, but they don’t know if the cows really need that supplement.
“With the unusual harvest conditions we’ve had this year in many regions, it will be even more important to do feed testing,” she says. A field that normally produces high-quality forage may be different this year for a variety of reasons. Harvest may have been delayed, allowing the forage to become overly mature. The forage may have gotten rained on multiple times before baling, or it may not have gotten enough water while it was growing and got too dry. Drought areas had poor regrowth and poor second cuttings.
“The stage of maturity might have been different this year, and growing season different. Rained-on forage loses quality, digestibility and nutrients,” Block says. “Some of the carbohydrates, vitamins and minerals get leached out.”
Some producers baled hay too wet because they didn’t have much choice, and it may contain mold and mycotoxins, she says. “It may also make protein potentially unavailable, tied up in the fiber. There were many challenges with harvest and storage this year. I tell people that if they’ve never tested their forages before, this is the year to start doing it!”
For a least-cost feeding strategy, and developing an adequate nutrition program, forage-testing is the place to start.
Editor’s note: Heather Smith Thomas is a freelance writer and cattlewoman from Salmon, Idaho. [Lead photo by Shauna Hermel.]
Angus Beef Bulletin EXTRA, Vol. 16, No. 9-A
Topics: Feedstuffs , Management , Nutrition , Pasture and Forage
Publication: Angus Beef Bulletin
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