Stocking Rates for Grazing Sugarbeet Tops
By Jeremiah Vardiman, UW Extension Educator
As an agriculture Extension educator, one of my main duties is answering various questions that are asked by the clientele. An intriguing question that was received this fall was, “What is the stocking density for cattle grazing on sugarbeet tops?”
This question highlights the ritual task of removing crop residues from the field. Crop residue is the portion of a harvested crop that remains in the field after the marketable portion of that crop is removed. The most economical means of removing crop residue from the field is through grazing.
Unfortunately, there is no stocking density for grazing sugarbeet tops in the research literature. Furthermore, grazing sugarbeet tops is barely mentioned in the latest research because the advancements in defoliating technology have limited the usefulness of this crop residue, and a majority of farmers have moved away from this practice.
Sugarbeet tops can be grazed by either sheep or cattle, with sheep making the best use.
Colorado State University established that sugarbeet tops are comparable to corn and sorghum residues as a supplemental feed source, with all three having a digestible dry matter content of 52 percent.
In terms of crude protein, sugarbeet tops provide the best source of protein, with 12.7 percent, followed by sorghum residue at six percent and cornstalk residue with 4.2 percent. The highest forage quality available for all crop residues is found immediately after harvesting and diminishes the longer it remains in the field.
The diminishing value of the feed is contrary to the needs of the livestock during November and December, especially mid-gestation livestock. Crop residues are typically inadequate for providing much weight gain to young livestock and insufficient for mid-gestation livestock since their needs increase the closer they get to their last trimester.
To assure livestock receive the necessary nutritional requirements, it is highly recommended that alfalfa hay be provided in their ration. When grazing crop residue in the field, this can be accomplished through feeding hay bales or allowing access to adjacent alfalfa fields. Even though sugarbeet tops are relatively high in crude protein, they should not be the sole roughage source in the diet. Providing free-choice hay provides more roughage in the diet while balancing nutrients such as calcium and phosphorus. One concern for grazing beet tops is the potential for livestock to choke on small beets that remain in the field after harvest.
For further discussion on this topic or others please contact your local Extension office.