Because of frost damage, some sunflower producers are considering harvesting their sunflowers as a silage this year.
“Sunflower silage can make a suitable feed for beef cows, but the challenge is getting it put up because sunflowers typically don’t dry-down well,” according to Greg Lardy, North Dakota State University beef specialist. “Consequently, dry feed must be added to the silage pile to reduce the moisture level to a point where seepage is not a major problem.”
Depending on what other feeds are mixed in the silage pile, nutrient contents may change. A laboratory analysis of the silage is recommended prior to feeding.
The moisture problem in sunflower silage can be corrected by several means. LaDon Johnson, former NDSU livestock specialist, suggests blending corn and sunflower silages together when packing as one method. He notes that one load of sunflower silage to 3 to 4 loads of corn silage as a ratio works well. This is assuming ‘average or normal’ moisture corn silage. Given the growing conditions in many parts of the state this year, immature corn silage may be too wet to use in this manner. Johnson also suggests waiting 7-10 days following a killing frost as a means of facilitating dry-down. Some varieties may take longer, but waiting increases the risk of wind damage to the crop.
Johnson also recommends blending dry forage into the silage pile as a means of reducing the moisture content. Optimal moisture content in sunflower silage appears to be 60 to 72 percent (28 to 40 percent dry matter). “In order to minimize seepage problems, the moisture level will need to be below 65 percent,” Lardy says. “Silage which is too wet will result in ‘sour’ fermentations which can be less palatable when fed and poorer nutrient content.”