Be ready to manage spring flush

LINDA GEIST

COLUMBIA, MISSOURI

Get a head start on pastures for the year with good management of spring flush, says University of Missouri Extension state forage specialist Harley Naumann.

Early decisions determine pasture health for the rest of the season, Naumann says.

Spring flush occurs when conditions exist for cool-season grasses to come out of their dormant state, usually when soil temperatures are around 55-65 F. In northern Missouri, this typically happens at the end of April to early May. Southern Missouri pastures are usually three weeks earlier.

Good management involves using this growth while it is at its peak nutritive value and digestibility, says Naumann.

Grazing at the right time takes advantage of the best cool-season grasses have to offer, he says. “Begin rotational grazing before pastures ‘look ready.’” If you wait until the first paddock looks ready, the last-used paddocks will be overgrown by the time you turn cows out on them. “Don’t wait until grass is 8-10 inches tall.”

Plan the order of grazing so that paddocks with the most forage are used first. Rotate as often as possible and as water supplies allow. Rapidly growing grass calls for rapid rotation. Adjust paddock size as needed.

“Everyone’s operation is different, so there is not a single recommendation,” he says.

Typically stocked operations often cannot use all this quick growth before it becomes too mature, Naumann says. Most rates are based on summer grazing needs. Spring’s abundance allows for higher rates.

If your operation allows, consider temporarily adjusting stocking rates and stocking density.

 “Stocking rate can be increased by adding stocker cattle to a cow-calf operation, for example, or by increasing stocking density by decreasing the area allocated to livestock,” says Naumann.

If you can’t increase stocking rates, set aside paddocks for harvest as hay, baleage or standing stockpile. Choose paddocks that offer the easiest access with machinery.

In continuous stocking systems, the spring grass flush can get away from the grazier. “Cows won’t eat the grass in the way we might want them to,” he says. “This puts the cow in charge.” Instead, implement a rotational system that allows the grazier to decide when and where the cow eats.

Avoid undergrazing by keeping a close eye on pasture height before, during and after each rotation. Adjust as needed. “Getting this right takes trial, error and practice,” he says. “You definitely learn by doing.”

Naumann notes that the crude protein and digestibility of early grasses declines throughout the season as plants mature. This affects beef and dairy cattle differently. Lactating dairy cattle always need high-nutritive-value forages to make milk. The spring flush of forage helps lactating dairy cows and spring-calving beef cattle. ∆

Linda Geist: University of Missouri