Care must be taken when turning cattle out on once-stressed pastures to protect against continuing a cycle of mistreatment, consequently resulting in poor forage quality and growth.
“Drought-like conditions last year forced some producers to overgraze pastures,” says Erika Lundy, an extension specialist at the Iowa Beef Center. “That plant stress will carry over and affect forage production this spring.”
Lundy states that the best course of action is to develop a grazing plan. To better utilize available forage, she recommends separating pastures into multiple paddocks to help improve yields. In the event that cattle must go on pasture early, splitting the available pasture also can ensure that a smaller amount of the acreage becomes damaged, she adds.
“Grazing cover crops provides a great opportunity to allow pasture acres to get a jump-start before cattle turnout,” Lundy says.
Producers are advised to monitor the height of their cover crops because for many, such as cereal rye, it only takes a month to head out and fully mature. Lundy recommends the “pluck test” to determine if forages are mature enough to graze.
She suggests holding a plant about 2 inches from the ground and giving it a good pull. If the root system comes completely out with the plant, grazing is not advised. However, if the leaf simply breaks off, it is strong enough to be grazed.
“Adding an annual forage source such as forage sorghum, spring wheat, or oats into your crop rotation may be another option to get some additional forage,” Lundy says.
Although it may be a little late to establish a cover crop, she notes that additional forage sources can help provide a recovery period later in the summer and be added into the grazing system.
Iowa State University preliminary research suggests that during wet, spring conditions, a layer of vegetative cover crops helps reduce compaction. Removing cattle, designating a sacrifice lot, and/or moving the minerals and feeding area around the paddock are all effective strategies for minimizing potential compaction.
“Regardless of forage source, lush, green cover crops or spring grass often contain high levels of potassium and low levels of magnesium compared to other times in the growing season,” Lundy says. “Grass tetany is a result of low magnesium intake at a time when lactating cows have a high magnesium requirement.”
To help prevent this, she suggests feeding minerals high in magnesium at least 30 days before turning cattle out on pastures. This should continue into the first few weeks of grazing, but monitor intake as these supplements are not typically desirable.
Finally, the beef specialist urges producers to contact their local extension beef or agronomy specialists for help in developing a grazing plan that fits their needs.