Midwestern producers should consider planting brown midrib sorghum-sudangrass on silage-corn acres left unplanted because of cold, wet weather. Planting as late as July 15 will still produce a one-cutting yield from the crop, says Frank Wardynski, Michigan State University Extension.
Brown midrib sorghum-sudangrass, a high-yielding forage with highly digestible fiber, can offer two cuttings if planted in June and dry-matter yields that nearly rival those of corn. A July 15 or early planting will yield one cutting if soil temperatures at germination are around 60-65º F, Wardynski says. Harvested at 36-48” tall, a BMR sorghum-sudan will provide energy content similar to corn silage’s; its crude protein will range from 15-20%.
Prussic acid poisoning can be a problem, he says. “Prussic acid is found in its highest concentrations in the leaves and new shoots, making grazing cattle most susceptible. Frost and severe drought frequently increase prussic acid content and should not be grazed under these conditions.”
But it’s usually not a problem in stored feeds, and prussic acid concentrations decrease during the sun curing and fermentation processes. Brown midrib sorghum-sudangrass can be stored as chopped silage, round-bale silage and dry hay.
Like what you're reading? Subscribe to eHay Weekly and get the latest news right to your inbox.
Another potential problem: The crop can hold water after cutting and not dry well for fermentation. “While this crop can dry rapidly under ideal drying conditions, the large mass of forage can inhibit drying, especially if the crop is allowed to grow to heights above 48”, Wardynski says, when forage quality rapidly decreases.
To aid drying, crimp the stems and lie the crop in a full swath, but avoid overdrying. It can also dry too rapidly, creating fermentation problems. He recommends chopping BMR sorghum-sudangrass between ¾" and 1” for bunker silos and slightly longer for upright silos and baggers to ensure effective fiber content.
“The final deciding factor of whether to plant an alternative forage crop may be the yield and progress of other crops,” he says.
“Some have indicated first-cutting alfalfa was harvested at high quality and yields were good. Conversely, corn is going to be close as to whether it will ripen and produce harvestable grain. If the corn crop doesn’t ripen or is damaged by early fall frost, lots of that will be chopped for silage. Decisions of planting an alternative forage crop may be determined based on the speculation of traditional forage supply.“
You may also want to read: