Alternative forages: One cut doesn’t fit all – Steve Murty, Vita Plus
Frustrating planting, growing and harvest conditions have encouraged more farms in the Midwest to look at alternative forage sources to feed their livestock. Steve Murty, Vita Plus forage specialist, told Vita Plus Custom Harvester Meeting attendees that these less-familiar crops can have great nutritional value if grown and harvested correctly.
“It’s all about accumulation of heat units and building that biomass for peak forage production,” Murty said.
He divided alternative forages into three categories – cool-season grasses, warm-season grasses and summer annuals. When and how these plants grow inherently affects the harvest strategy and incorporation in a livestock feeding program.
Producers with tight forage inventories this spring may look to cool-season grasses as fast forage sources. Murty said a lot of producers have found success with planting Italian ryegrass in the spring and described it as a high-quality, leafy, and palatable forage. He said it has good seeding vigor, but seed-to-soil contact is essential.
Italian ryegrass may also be incorporated into a season-long forage strategy by underseeding it with spring cereals. This may be used as wet forage or dry hay.
Italian ryegrass can be difficult to handle when harvested in its vegetative state. One custom harvester in attendance said he put up Italian ryegrass last season and described the process by saying “it’s like lawn clippings.” However, he said the subsequent silage made from the crop has been a great dairy feedstuff.
Murty said small grain forages – such as oats, triticale, barley, spring wheat and winter annuals – can also fit nicely into a farm’s forage program. Harvesting at the right development stage is key to the feed quality of these forages.
Speaking about oat forage specifically, Murty said, crude protein goes down and NDF goes up as a crop becomes more mature. He said harvesting closer to the boot stage provides a better-quality forage.
Murty said sorghum can also be a “powerhouse” crop in the right situations. It creates a lot of biomass in a short amount of time, so it can be used as a “fill-in” crop if the primary crop fails. It’s also cheap; Murty said it costs between $10 and $15 to plant an acre of forage sorghum, compared to about $125 to plant an acre of corn. Sorghum is a water-efficient plant, so it may also be a good choice in dry years.
Providing more tonnage than straight sudangrass, sorghum-sudangrass hybrids may be a good choice for farms looking to fill multiple-harvest systems. It can be grazed, used for hay production, or put up as silage. Murty noted that this crop must wilt prior to chopping to ensure the proper moisture content.
Just as a major portion of corn silage’s feed value is determined by its kernel processing score (KPS), Murty said the berry processing score (BPS) for sorghum should be closely monitored. In corn silage, KPS is determined by how much of the starch passes through a 4.75 mm sieve. Recent research has indicated that a 2.36 mm sieve is a good measure for BPS. For sorghum harvest, Murty said processor settings similar to what’s used for corn silage should achieve adequate BPS.
5 C’s of ensiling
Murty concluded by sharing the “5 C’s of quality silage,” which were first outlined by Hugo Ramirez of Iowa State University:
- Consider (moisture content)
- Grain silages: 62% to 68% ideal
- Alfalfa and grass silages: 58% to 64%
- Cut (theoretical length of cut)
- Processed corn silage: 0.75 inches (19 to 22 mm)
- Hay and small grains: less than 0.625 inches (15 mm)
- Crack (kernel processing)
- No whole kernels (set the roll gap between 1 and 3 mm)
- KPS of 50% to 70% is considered adequate
- Cram (packing)
- A density of at least 15 pounds of dry matter (DM) per cubic foot is critical for oxygen removal
- Sealing with a high-efficiency oxygen barrier film promotes nutrient retention and DM recovery
- Further protect the pile or bunker with a quality black-and-white plastic