UNL Extension Educators discuss considerations for grazing alfalfa during fall and winter months
In a BeefWatch newsletter, dated Oct. 1, University of Nebraska-Lincoln (UNL) Extension Educators Brad Schick and Ben Beckman discuss the benefits and considerations of grazing alfalfa during fall and winter months.
“There is often fear associated with grazing alfalfa due to bloat potential or hurting the alfalfa stand. These are valid concerns, but with additional management and timing, alfalfa stands can provide supplemental forage,” Schick and Beckman say. “In a haying system during the spring and summer, fall and winter grazing may be an option to harvest quality feed.”
Fall grazing
Schick and Beckman note there are several benefits to grazing alfalfa in the fall. These include providing animals with a high-quality forage resource, as well as eliminating any issues with poor drying if producers are trying to make hay.
“In the fall, other pastures may already be fully utilized and crop residue unavailable or temporarily unavailable,” they point out.
The two educators note research conducted at UNL has shown yearlings can have 1.5 to 2.5 pounds per day of average daily gain (ADG) and cows can increase body condition score before harsh winter months when grazing alfalfa in the fall.
They also explain before grazing, alfalfa needs six weeks of growth, uninterrupted by grazing or haying to properly winterize, which allows plants to accumulate energy in the roots.
Since fall-grazed or hayed alfalfa is generally very high in quality but low in quantity, Schick and Beckman note producers should only allow animals to graze lightly, leaving at least eight inches of stubble on average.
They also suggest using rotational grazing so animals are less likely to overgraze a given area.
“Plans should be made so grazing can be done when the field is dry and firm,” Schick and Beckman explain. “If the soil is too wet, animal hooves can damage plant crowns. The same principle applies to driving equipment on the fields as well. Having a sacrifice area or an adjacent lot ready to pull animals into if conditions get too wet can help producers avoid excessive damage to the stand.”
Winter grazing
While producers may benefit from grazing alfalfa during the winter months as well, Schick and Beckman remind them it is important to wait until after a killing frost before they graze the field in order to limit damage to alfalfa stands.
“Once the hard frost occurs, the stand can be harvested. Cutting or grazing needs to take place shortly after the killing freeze to salvage as much of the nutritive value as possible,” they explain.
Schick and Beckman note, compared to fall alfalfa, the quality and quantity of the particular forage will decline rapidly during winter months as the alfalfa plant desiccates.
“For this reason, winter alfalfa stands will seldom provide enough nutritional value to be a primary forage source for animals,” explain Schick and Beckman. “Grazing soon after a killing freeze will aid in capturing the best value from the alfalfa.”
After the ground is frozen, the two experts also point out the danger of hoof damage to plant crowns will also be reduced.
“Protecting the plant from weather extremes is critical to prevent stand winterkill. When winter grazing, producers should be sure to maintain at least four inches of stubble height,” they state.
Bloat considerations
As with all high-quality forage, it is important for producers to keep in mind bloat may be a concern when grazing alfalfa during fall and winter months.
According to Schick and Beckman, bloat risk is highest during the first three to five days after a freeze, when cattle are first introduced to an alfalfa field, when heavy dew is present or if cattle have low rumen fill.
Schick and Beckman state proper animal management practices are the key to limiting bloat.
“When initially turning animals out to graze an alfalfa stand, producers should pre-feed animals before allowing grazing access and then only allow grazing for an hour or two,” they say. “Moisture from rain or dew can also aid in bloat, so initial grazing should occur later in the day.”
Additionally, Schick and Beckman recommend producers slowly build up the time they allow their animals to graze over a period of several weeks to allow the rumen to adjust to the high-quality diet.
“More mature alfalfa stands are lower quality and pose a lower risk for bloat. Providing a lower-quality roughage source like crop residues or grass hay can provide animals fill and reduce risk,” they explain.
“When grazing in the fall, freeze events followed by warm days also raise the risk of bloat, so pull animals off or limit grazing for three to five days after a freeze,” they further suggest, explaining freezing damages cell walls in a plant, which makes proteins and minerals more readily available for digestion.
“Once cold temperatures set in, bloat risk decreases and becomes very low once 50 to 70 percent of the alfalfa is frozen and dried,” Schick and Beckman conclude. “Typically, this will occur in the late fall, but warm and wet fall conditions may keep alfalfa growing until the early winter months.”
Hannah Bugas is the managing editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.
