COLUMBIA, Mo. -- Warm weather after a long, cool spring will make grass growth jump in pastures and hay fields, said Rob Kallenbach, University of Missouri Extension forage specialist.

"Producers must be prepared to deal with a lot of extra growth," he said.

Soils moisture was plentiful this spring, so all it takes is some sunshine and warmth, Kallenbach said.

Forage graziers who measure growth in their paddocks have been getting about 40 pounds of dry-matter growth per day per acre in mid-April. That was when soil temperatures were still low, in the 40-degree range. When soil temperatures increase to 55 degrees, production goes up sharply.

"We'll be seeing about 80 to 90 pounds per acre per day," Kallenbach said. "At 40 pounds, you think you are a good forage manager. At 80 pounds, things fall apart as forage growth gets ahead of the livestock."

A challenge for pasture managers is to keep forage grazed down so that plants don't set seed heads, he said. Once a plant sets seed, it stops growing leaves. With intensive grazing, livestock prevent seed head formation.

"The secret to pasture management is keeping the forage in the vegetative stage," he said.

For easier pasture management, farmers divide large pastures into smaller grazing paddocks and move their herds from one to another every couple of days. By concentrating large numbers of animals on a smaller acreage, grass can be grazed down uniformly. No plant escapes nipping, preventing set of seed heads.

Seed control is important on tall fescue, the most common grass in Missouri pastures. Most fescue plants are infected with an endophyte fungus that makes a toxin that retards animal growth. While the whole plant can contain endophyte toxin, it becomes concentrated in the seed heads.

If cattle cannot keep up on eating the grass growth, some paddocks should be set aside for hay harvest. For best nutritional content, that grass must be cut for hay before seed heads set.

Kallenbach alerted alfalfa growers to watch their fields closely as the weather warms. "The first cutting of alfalfa will be due about the first week of May. It might not look like it now, after a cool spring, but it will grow quickly with warmer temperatures," he said.

Alfalfa should be harvested before full bloom and seed set. Cutting when plants are at first bloom gives the best compromise on yield and quality.

To take advantage of haymaking days, all haying equipment should be checked and ready to run. "Haying time is closer than anyone thinks," Kallenbach said.

To cut haying costs, Kallenbach urges management-intensive grazing when possible.

Increasingly, graziers use rising-plate meters to measure the daily dry-matter growth in each of their grazing paddocks. The cane-mounted device can measure pasture growth as the producer walks through a paddock. Most users are dairy producers, Kallenbach said, but beef producers also are adopting the measuring devices, which are imported from New Zealand.

Results of the regular forage measurement are plotted on a grazing wedge, using software. MU Extension has developed an online grazing-wedge calculator, available here. The online tool also allows producers to view grazing wedges that participating farmers have volunteered to make public.

SOURCE: University of Missouri.