Choosing the Right Supplemental Feeds for Beef Cows

In cow-calf production, forage is the foundation of the diet. However, there may be situations when forage quality or quantity limits animal productivity. In these cases, supplementation becomes necessary to maintain cow performance. Supplemental feeds can be used to provide additional nutrients when forage alone does not meet animal requirements. Depending on the feedstuff selected, supplements may contribute energy, protein, minerals, vitamins, or a combination of these nutrients. However, selecting the appropriate supplement is critical. The goal with supplementation is to support forage utilization, not hinder or replace it.

Traditionally, cereal grains are considered to be energy supplements. These feeds are typically high in starch content, low in crude protein, and have little fiber, making them high in non-structural carbohydrates (NSC). While grains are often selected due to their high energy content and availability, they can negatively impact the rumen function of beef cows when eaten in excess. Starch is rapidly degraded in the rumen by microbes, which can reduce rumen pH. The fiber-degrading bacteria in the rumen are sensitive to low pH and become less effective under low pH conditions (Hoover, 1986). When forage digestion is reduced, cattle do not fully utilize the base of their diet. This is known as a negative associative effect, where the supplement reduces forage intake or digestibility instead of improving it. In these cases, the cattle’s condition may not respond as expected, even though additional feed is being provided (Bowman & Sanson, 1996; Horn & McCollum, 1987).

To minimize these negative effects, starch-based supplements such as corn should generally be limited to approximately 0.25% of a cow’s body weight to maintain forage utilization. For most mature beef cows, this equates to approximately 3–4 lb of corn per day. Feeding higher levels (greater than ~0.4% of body weight) has been shown to decrease forage intake and digestibility (Kunkle et al., 2000).

In contrast, supplementing additional protein can improve forage utilization, particularly when cows are consuming low-quality forages (< 7%–8% crude protein) (Moore & Kunkle, 1995). Protein supplements provide additional nitrogen in the rumen, which is important for microbial growth and activity. Insufficient rumen nitrogen impairs microbial fermentation, decreasing forage digestibility. Improvements in both forage digestibility and intake have been observed in cattle when their high-forage diet is supplemented with protein (McCollum & Horn, 1990).

Many co-products can serve as effective supplements for beef cows. Co-products such as soybean hulls, wheat middlings, corn gluten feed, distillers grains, and brewers grains are typically high in total digestible nutrients (TDN) (> 75%), low in starch (< 30%), and moderate to high in CP (> 12%) (Kunkle et al., 2000). Because of this nutrient profile, co-products provide energy while maintaining a rumen environment that supports fiber digestion, making them a strong alternative to starch-based supplements.

Determining the appropriate type and amount of supplementation should be done on an individual herd basis. First, a forage analysis should be conducted to identify nutrient deficiencies in the base diet. An effective supplementation program begins with understanding what nutrients the forage is supplying and where deficiencies exist. Second, producers must consider a cow’s stage of production. Nutrient requirements are highest during early lactation and lowest during mid-gestation. Additionally, first-calf heifers have greater nutritional demands than mature cows because they are still growing.

Ultimately, supplementation strategies should be designed to complement forage, not replace it. Selecting the right supplement type and feeding it at appropriate levels ensures that forage remains the primary nutrient source, maximizing both cow performance and feed efficiency. No one-size-fits-all supplementation program is available because forage quality, animal requirements, feed costs, and supplement availability vary among operations. Producers should use forage test results, monitor body-condition scores, and work with an Extension specialist or nutritionist to develop a supplementation strategy that meets herd needs while making efficient use of available forage resources.

References

Bowman, J. G., & Sanson, D. W. (1996). Starch- or fiber-based energy supplements for grazing ruminants. 3^rd Grazing Livestock Nutrition Conference, Custer, South Dakota.

Hoover, W. H. (1986). Chemical factors involved in ruminal fiber digestion. Journal of Dairy Science, 69(10), 2755–2766.
doi.org/10.3168/jds.S0022-0302(86)80724-X

Kunkle, W., Johns, J., Poore, M., & Herd, D. (2000). Designing supplementation programs for beef cattle fed forage-based diets. Journal of Animal Science, 77, 1–12.
doi.org/10.2527/jas2000.00218812007700ES0012x

McCollum, F. T., & Horn, G. W. (1990). Protein supplementation of grazing livestock: A review. The Professional Animal Scientist, 6(2), 1–16.
doi.org/10.15232/S1080-7446(15)32251-8

Moore, J. E., & Kunkle, W. E. (1995). Improving forage supplementation programs for beef cattle. 6th Annual Florida Ruminant Nutrition Symposium, Gainesville, Florida.

National Academies of Sciences, Engineering, and Medicine (NASEM). (2016). Nutrient requirements of beef cattle (8th rev. ed.). The National Academies Press.
nationalacademies.org/publications/19014