As drought conditions persist, cattle producers should consider feed resources that can complement low quality forage. With the increase in soybean processing facilities in Nebraska, one of the major co-products of these plants is soybean hulls. These can be sourced either loose or as pellets. Soybean hulls are light and fluffy and thus are often pelleted to increase bulk density and ease of handling and transport.

Soybean hulls run around 90% dry matter and 12% crude protein but can range from 9-14% crude protein depending upon the source. Soybean hulls in cattle diets have been shown to have an energy value of 64% to 80% total digestible nutrients, depending upon the other sources of feed in the diet and the total amount of soybean hulls that are fed. In a forage-based diet, when supplemented at 0.5% body weight, soybean hulls have been shown to have an energy value nearly equal to corn, or as high as 80% total digestible nutrients on a dry matter basis. Feeding soybean hulls at 20-30% of the diet on a dry matter basis appears to often be an optimum level of inclusion.

Because soybean hulls are low in lignin, the cellulose is highly digestible in the rumen, and fermentation rates are rapid. This also means that when soybean hulls are fed at a high percentage of the diet, bloat can be an issue. When fed at higher levels as a percent of the diet, with limited long stem forage, the small particles present in the soybean hulls pass rapidly through the digestive tract. This results in a reduction in the amount of time that soybean hulls spend in the rumen, impacting the effectiveness of rumen microbes in breaking down and utilizing the fiber as an energy source. Long stem forage or other lower quality roughages serve to slow the rate of passage and increase the amount of time soybean hulls spend in the rumen, thus increasing the fiber digested.  

When comparing soybean hulls to other feed resources, compare them on a price per pound of dry matter nutrient (protein and energy) in the diet that will be consumed by the animal. Soybean hulls and pellets are quite palatable, and are readily consumed, making them an excellent component of creep feeds and diets for calves at weaning. Because the energy in soybean hulls is from highly digestible fiber, they are an excellent complement to forage-based diets.  

They fit especially well in situations where medium-to-low quality forage is the primary feed source. Because of their nutrient profile, one pound of soybean hulls on a dry matter basis could replace 1.5 to 2.0 pounds of low to medium quality hay, providing a high-quality fiber-based energy and protein source that can be utilized to enhance the ability of rumen microbes to utilize forage resources. Soybean hulls tend to have a “synergistic effect” when fed to cattle with free access to medium to low quality forage. This means that it doesn’t replace on a 1:1 basis the forage cattle are consuming and will in many cases actually increase the total dry matter consumption.

Nebraska Extension Livestock Educators and Specialists are available to help develop rations or supplemental feeding plans to meet cattle needs during drought conditions.

Sources:  

Beef Cattle Handbook “Alternative Feeds for Beef Cows and Stockers”

Nutrient Requirements for Beef Cattle 2016 Edition

Anderson, J. (1988) Soybean Hulls as an Energy Supplement for the Grazing Ruminant. Journal of Animal Science, Volume 66, Issue 11, Pages 2959–2964.