Grazing Residues Following Harvest
Grazing is the easiest way to harvest crop aftermath. Grazing crop residues allows animals to select a higher-quality diet than would otherwise be obtained by harvesting and mechanically feeding. In grazing scenarios, ruminants preferentially will consume grain and leaves before consuming lower-quality stalk material. This is an important consideration when developing diets based on crop residues. Stocker cattle may have acceptable gains if allowed to selectively graze residues. Younger cattle should be removed from the field or supplemented with protein and energy feeds once high-quality residue components are consumed. Depending on the number of animals and the acreage, stocker cattle can graze on residues until cattle performance declines or feed quantity or quality becomes limiting.
Standing small grains (immature or mature) can be used in grazing situations for beef, sheep and dairy. In years where the harvest occurs early, some small-grain fields will have substantial regrowth, with young plants having nutrient content similar to alfalfa (may be greater than 30 percent crude protein). Plant residue with the feeding equivalent of baled straw also may be available for animals to consume. As with any other postharvest grazing, producers should be aware of any grain spills that happened during harvest and attempt to remove or redistribute the grain from a single pile before animals are allowed to graze. Some fall planting scenarios of winter wheat, winter barley or winter rye may allow for grazing after plants tiller, but try to remove the cattle two weeks in advance of the final frost to allow plants to put reserves back into their crowns. In cases of crop failure or wind/hail damage, small-grain fields also can be grazed in the spring/summer. Caution is needed in many cases when planning to graze grain that is maturing: High nitrate concentrations can be present if growing conditions have been excessively dry, ergot can proliferate if growing conditions have been wet, and digestive upsets can occur if grain is approaching maturity.
Field pea residue includes residual vines, leaves and stems. Field pea residue is a palatable and nutritious residue often
resembling medium-quality grass hay in nutritional content. However, field pea straw appears to be quite variable (4 to 12 percent CP; 40 to 60 percent TDN). Consequently, we recommend a nutrient analysis prior to feeding. Peas are harvested in the early fall, so grazing or baling are options for utilizing pea straw. Windrows may blow around or the straw may wrap on rotating equipment such as stack wagons or balers. Field pea residue decomposes more rapidly than cereal crop residues. Therefore, it should be harvested or grazed shortly after combining to minimize loss of leaves and retain nutrient quality.
Information for this article came from North Dakota State University Extension. The title of the document is Alternative Feeds for Ruminants (AS1182). The document is available online, and provides information on grazing a variety of different crop residues.
