Ohio State University Extension Factsheet

Ohio State University FactSheet

Animal Sciences

2029 Fyffe Road, Columbus, OH 43210-1095

Winter Supplementation of Beef Cows


Clif Little

Stephen Boyles


Forage can provide most of the nutritional requirements of a beef herd during the fall and winter months. The challenge becomes the management of supplement due to variations in forage quality and growth. Several options available to the cow-calf producer for the management of forage and supplement are discussed here.

Extending the Grazing Season

Identify soil and forage resources that are candidates for stockpiling. South-facing slopes of fescue and orchardgrass have responded well to applications of 50 pounds of actual nitrogen per acre. Timing the fertilizer application shortly after the last summer harvest, approximately July 31, will maximize forage yield production and increase forage nutritional quality. Choose to stockpile clean, weed-free, gently sloping fields (i.e., less than 25 percent). Rotationally grazing stockpiled forages increases forage availability while allowing time for regrowth. Strip grazing with hay bales left in the field will further extend the days on pasture. Use electric wire or tape to control access to only a few bales at a time. When feeding hay, producers may choose to unroll round bales or place them in feeders. Both of these alternatives may reduce hay wastage.

Consider the Use of Annual Forages

Brassica, pearl millet, sorghum-sudangrass, corn stalks, grazing corn, rye, wheat, and oats can provide for fall and winter grazing. These annual forages can provide nutritious alternatives when stockpiled pastures are given a rest. OSU Extension Bulletin 872 discusses the use of these alternatives in further detail.

Strategic Culling and Sorting of the Cow Herd

After weaning, consider selling open cows or cows with poor health, bad eyes, deformed udders, poor dispositions, or bad feet. Two-thirds of the cost for maintaining a cow can be eliminated if we do not have to carry her through the winter.

Sorting according to body condition score (BCS 1 = Thin and BCS 9 = Fat) and supplementing according to nutritional needs can further reduce the cost of winter supplementation. Manage weaned heifers and older cows with BCS of less than 5 in separate groups. Allow grazing heifers and cows needing an improvement in body condition to graze first, or allow them to graze better quality pastures. Cows in BCS of 5 or higher can graze pastures following these other groups. OSU Extension Bulletin L-292 has pictures of the various body condition scores.

Wide variation in body condition score can be due to age and breed composition within the herd. Watch out though; variation can simply be due to inadequate bunk or hay rack space! The benefits from supplementation can be enhanced when supplementation is started before the onset of cold weather. It is easier to alter cow body condition score during mild, fall weather than during harsh, winter weather.

Determine the Nutritional Value of the Existing Forage

To properly supplement livestock, each forage should be sampled and analyzed. OSU Extension forage testing fact sheet, ANR-2-98, describes the proper sampling techniques for various forages and explains the results. Contact your local Agriculture Extension Agent for a test probe and instructions for submitting the sample to a laboratory. Forage quality may have a dramatic impact on dry-matter intake. The higher the NDF (neutral detergent fiber) content of forage, the less forage an animal will be able to consume. Cattle will generally consume 1.2 to 1.5% of their body weight per day in forage NDF. Supplementation when forage intake is greater than 1.75% of body weight may decrease forage intake.

Protein Supplements

Protein supplements can increase low-quality forage digestibility and intake while extending the grazing season. Limited amounts of high-protein supplements greater than 30 percent crude protein (CP) can be used with low-quality forages (less than 8 percent crude protein and 45 percent total digestible nutrients [TDN]). High-concentration protein supplements that are natural protein sources do not need to be fed every day. Simply feed twice as much every other day. When forage is of 8 to 10 percent crude protein content, a 20 percent crude protein supplement can be fed daily. Protein supplements containing nonprotein nitrogen can be used, but only in limited amounts, and should be provided on a daily basis.

Cost of Protein Supplements

A simplified method of determining cost per unit of crude protein follows:

Soybean Meal, 50% Crude Protein (as fed) at $236/ton:

2,000 lb. soybean meal x 0.50 = 1,000 lb. crude protein

$236/1,000 lb. = $0.24 cost per unit of crude protein

Cottonseed Meal, 41% Crude Protein (as fed) at $230/ton:

2,000 lb. cottonseed meal x 0.41 = 820 lb. of crude protein

$230/820 lb. = $0.28 cost per unit of crude protein

These calculations illustrate the importance of comparing the cost of protein when considering the purchase of a protein supplement. Producers may also want to consider the mixture of protein being provided. These calculations don't consider concentrations of rumen degradable protein and "bypass" protein sources. For proper rumen function, a portion of the dietary protein must be degraded in the rumen for microbial growth, and the rest can be absorbed later in the digestive tract. Providing a mixture of microbial protein and bypass protein will maximize animal production. Low-bypass protein sources include casein, soybean meal, sunflower meal, and peanut meal. Medium-bypass sources include alfalfa meal and brewers dried grains. High-bypass sources include meat meal, corn gluten meal, feather meal, fish meal, and formaldehyde-treated proteins.

Value of Supplements

The previous example of cost per unit of crude protein is only part of the information when determining which supplement to use. Other considerations are availability of the supplement, feeding method, time required to feed, and service provided with the supplement.

Typically cubes, cakes, blocks, and tub supplements may have a higher cost per unit of nutrient supplied. However, they can be easier to feed and require less daily management. A meal- or pelleted-based supplement may require feed bunks to effectively provide the supplement to cows whereas cubes, blocks, and tubs are ready to feed and do not require a feed bunk. Distance from the cows also needs to be considered. Blocks and tubs can remain with the cows whereas a bag supplement must be transported to the cows on a fairly regular basis.

Supplements developed by feed companies often will contain additional minerals, vitamins, and selected feed additives. Simply calculating cost per unit of a single nutrient fails to take into account the benefits of these added products.

Selecting an Energy Supplement

In many cases, our forages may be adequate in protein to meet the requirements of gestating cows but may lack sufficient energy. Energy units may be Total Digestible Nutrients (TDN), Net Energy Gain (Neg), and Net Energy Maintenance (Nem). Price per unit of nutrient will vary within the same feed depending upon the unit you use for comparison. Grain usually contains a readily available starch. Grain sugar and starch ferments rapidly in the rumen and may lower rumen pH, resulting in reduced feed intake and digestibility of forages. It is therefore recommended that the amount of grain be limited when used in a forage-based diet. Certain feeds such as soybean hulls, corn gluten feed, beet pulp, and brewers grains are satisfactory energy sources, but the starch is more slowly degraded and does not alter rumen pH to the same degree as grain sources such as corn.

Comparing the cost of TDN, we can estimate the cost of energy supplements as we have done for protein supplements in the previous example.

Hay valued at $60/T

$60/20 (100 lb. increments) = $3 per 100 lb. hay

$3/0.50 (% TDN as fed) = $6.00 per 100 lb. TDN

Corn valued at $70/T

$70/20 = $3.50 per 100 lb.

$3.50/0.80 (%TDN as fed) = $4.38 per 100 lb. TDN

Soybean hulls valued at $85/T

$85/20 = $4.25 per 100 lb.

$4.25/0.70 (% TDN as fed) = $6.07 per 100 lb. TDN

Like protein sources, energy sources also vary amounts of mineral and vitamin available. For this reason, it is important to consider the cost per unit of nutrient along with the ease of handling, amount of concentrate fed, forage quality, and type. In addition, protein and energy sources that differ significantly in dry-matter content should be adjusted and compared on a dry-matter basis. For these calculations, we have used (as-fed) values for crude protein and Total Digestible Nutrients. If we had utilized book values, based on a 100% dry-matter basis, we would simply divide the cost per unit (CPN TDN) by the percent dry matter (decimal value) of the feed ingredient.

Comparing Various Levels of Forage Quality in Balancing Beef Cattle Diets


1,000-lb. cow nursing calves - first 3 to 4 months postpartum in superior milk (20 lb/day)

Her requirements:

Dry Matter 20.6 lb/day
Crude Protein 2.5 lb/day
TDN 13.8 lb/day

Source: OSU Extension, ANR-2-98

Let's Consider Two Different Hay Sources

Fescue hay 8% CP and 0.44% TDN (dry-matter basis) and fescue hay 12% CP and 0.61% TDN (dry-matter basis)

Table 1 compares two different forage quality values and the amount of supplements that would need to be fed to provide a balanced ration for a 1,000-lb. cow in peak milk production.


Table 1. Daily Levels of Supplements Required for a 1,000-lb. Cow During Peak Milk Production.


8% CP and 0.44% TDN

12% CP and 0.61% TDN

4.74 lbs. deficient in TDN

1.23 lbs. deficient in TDN

0.85 lbs. deficient in CP
0.1 lb. deficient in CP

lb. corn needed (as-fed basis)



lb. 50% SBM needed (as-fed basis)



lbs. hay needed (as-fed basis)



approximate cost1

100 cows for 60 days



1Cost calculations based on corn at $70/T, hay $50/T, and 50% SBM at $236/Ton. Local prices will vary. Table 1 illustrates the relative value of various quality forages in a feeding program and should not be used as a guide.


Many times it is not economical to feed cattle to meet all of their nutritional requirements throughout the year. However, not meeting nutritional requirements of heifers and cows during the last third of pregnancy and the first 60 days of lactation may cost producers great economic loss. Breeding animals not fed properly during these stages of production can be expected to exhibit low birth-weight calves, poor conception rates, greater calf death loss, longer intervals between calving and re-breeding, and depressed weaning weights of calves. Maintaining an acceptable body condition score throughout the year will help to minimize these losses. Feeding first-calf heifers to reach puberty by 14 months of age or younger and at 60 to 65 percent of the mature weight at puberty should be a target. Utilizing target weights for replacement females can simplify the feeding program.

For example, consider a heifer that will have a 1,000-lb. mature weight on a medium frame. If this heifer weighs 400 lb. at weaning (40 percent of mature weight) and we expect her to weigh 650 lb. at breeding (65 percent of mature weight), she will need to gain approximately 150 lb. in 285 days to calve at 80% of her mature body weight.

The cheapest time to improve body condition score is after breeding through weaning or from approximately the third month of pregnancy to the seventh month. Timing cattle nutritional requirements to match seasonal forage production will also help to reduce feed costs.

The most critical time for evaluating BCS is the last 60 to 100 days prior to calving, at calving, and at the beginning of the breeding season. The highest nutritional requirements will be the last 50 days of gestation and 80 to 90 days following calving. Animals needing adjustment in BCS should be grouped and fed according to their nutritional requirements. Depending on your breeding program, it may be cheaper to improve body condition score during periods of rapid forage growth (i.e., fall and spring).

Mineral Supplementation

Breeding livestock should be allowed free-choice access to a complete mineral supplement. Table 18 of OSU Extension Bulletin 872 and Extension Fact Sheet ANR-2-98 lists the mineral requirements of beef cattle. When feeding mineral supplement, one can estimate the ounces consumed by accurately weighing the mineral mixture, returning 10 days later and re-weighing. Repeat this step several times to increase accuracy. The steps given here can be utilized in calculating grams per day of mineral supplement being consumed.

Cost vs. Value of Vitamin/Mineral Supplements

Different mineral sources vary in bioavailability of mineral and also in cost. Select mineral supplements that use suitable sources of minerals. The value of the mineral supplement also depends on palatability of the mineral supplement. A cheap, home-made mineral mix that is not consumed by the cattle has little value.


Step 1

Pounds mineral consumed per day

(The amount consumed changes with forage quality and should be balanced accordingly.)


Initial weight of mineral mixture (lb) - weight 10 days later (lb)

10 days

Step 2

Ounces/day consumed


Pounds/day consumed x 16

Step 3

Ounces consumed per head


Ounces consumed per day

Number of cattle utilizing supplement

Step 4

Grams of mineral supplement consumed per head per day


Ounces consumed per head


Knowing the grams of mineral supplement consumed per head will allow producers to compare daily requirements to daily mineral consumption.



The strategies for reducing winter feed cost are as numerous as cattle breeds. Proper decision making for reducing winter feed cost starts with identifying the nutrient composition of available feeds. The next step is to maintain adequate BCS and growth rate of reproductive females. Finally, supplement according to the proper nutrient balance needed for groups of livestock and cull nonproductive animals prior to winter. Finally, strategically de-worm and de-louse cattle to avoid losing cheap gains on pasture.

For assistance in calculating the supplement required in your feeding program, contact your local Agriculture Extension Agent.

Special Thanks

The authors would like to thank Dave Mangione, Ohio State University District Specialist; Jeff Fisher, Ohio State University Extension Agent, Pike County; and Don Potts, Guernsey County beef producer, for reviewing this document.


Caton, J. S. and D. V. Dhuyvetter. 1996. Influence of Energy Supplementation on Grazing Ruminants: Requirements and Responses. J. Animal Science 75:533.

Mangione, D. A. 1992. Scoring Cows Can Improve Profits. Ohio State University Extension, L-292.

NRC. 1996. Nutrition Requirement of Beef Cattle. 7th Ed. National Academy Press, Washington, D.C.

Ohio State University Extension. Forage Testing for Beef Cattle. Extension Fact Sheet ANR-2-98.

Ohio State University Extension. Maximizing Fall and Winter Grazing of Beef Cows and Stocker Cattle. Bulletin 872.



Click here for the PDF version of this fact sheet.

All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.

Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension.

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