Feed accounts for approximately 56 percent of those annual operating expenses. The cost of feed to maintain the cow herd through the winter represents 70 to 75 percent of the total annual feed costs.
Considering the magnitude of winter feed costs, it is easy to see that advantages exist for producers who develop and maintain plans that allow the cow herd to be fed during the winter in an efficient and effective manner.
Following are some approaches producers can take to help cows make it through the winter and set them up for future stages of production.
Hay quantity and quality
In preparation for the winter feeding period, producers should inventory their hay stocks and make sure there is an adequate amount of hay to get the cow herd through the winter. To be most accurate in determining how much hay is available, actual weights of bales should be taken.
If producers are unable to weigh each bale, they should at least weigh several bales and use the average weight in calculations. The inventory of feedstuffs should be monitored regularly throughout the winter and, if shortages are anticipated or noted, actions should be taken to fill the void.
In addition to this measure of hay (feed) quantity, producers should also get a measure of hay (feed) quality. This can be accomplished with a feed analysis.
A feed analysis determines the nutrient composition of the feedstuff and provides a measure of certainty with regards to the safety of the feedstuff. The nutrient composition can be coupled with the animals’ nutrient requirements to achieve a proper diet (ration) formulation.
To gauge the amount of feed needed by cows in the herd, producers often use 2.5 to 3 percent of a cow’s bodyweight to determine the amount of dry matter needed by a cow per day. As an example, a 1,200-pound cow would need 30 to 36 pounds of dry matter each day.
To accurately determine the amount of hay needed, and make sure the right amount of hay is being provided, producers must account for the moisture content of the hay. If our hay tested to be 90 percent dry matter, then we would divide the 30 to 36 pounds by 90 percent and find that our 1,200-pound cow would need approximately 33 to 40 pounds of hay per day on an as-fed basis.
Ambient temperature is the temperature an animal experiences. As the temperatures fall, a cow’s metabolic activity increases, as does the passage rate of roughages through the rumen. Generally, as ambient temperature decreases, a cow’s voluntary intake increases.
This relationship is shown in Table 1. If we consider temperatures below 5ºF, the results in the table suggest that 16 percent more dry matter would be required to meet a cow’s intake needs as dictated by appetite.
Coat and water
Hair coat condition is a major factor in determining an animal’s lower critical temperature. The lower critical temperature is defined as the ambient temperature at which a cow’s energy intake must increase to prevent or minimize weight loss. Table 2 lists various lower critical temperatures for animals with different hair coats.
Generally, for each degree (ºF) below the lower critical temperature, a cow’s energy intake must increase by 1 percent to prevent weight loss. If a cow with a dry, winter coat (lower critical temperature = 32ºF) experienced an ambient temperature of 25ºF, we would need to provide 7 percent more energy to prevent her from burning energy stores and losing weight.
While often not thought of in the winter, water is needed by cattle for temperature regulation, digestion, absorption and utilization of nutrients, elimination of waste and a variety of metabolic functions.
The water requirements and water consumption of beef cattle are influenced by a number of factors, including age, weight, type of diet, moisture content of ration, level of intake, pregnancy status, lactation, level of activity, relative humidity and environmental temperature.
Table 3 lists the water requirements of beef cattle at various ambient temperatures. While winter can present unique challenges to producers delivering water, cattle must be provided a ready source of high-quality water to perform optimally.
Sorting by age
To meet the nutritional requirements of the cow herd and allow for maximum productivity, beef producers should sort their herd into groups with similar nutrient and management requirements. The winter feeding period for many beef operations includes the middle and last trimester of gestation and part of the first trimester of lactation.
To gain some understanding of the nutritional requirements of various classes of cattle, and begin thinking of how cattle should be grouped (sorted), consider the requirements of a first-calf heifer versus a mature cow.
A 900-pound, 2-year-old heifer in the last trimester of pregnancy requires a feed that contains 59 percent total digestible nutrients and 8.5 percent protein. A 1,300-pound, pregnant, mature cow in the last trimester of pregnancy requires a feed that is 52 percent total digestible nutrients and 7.7 percent protein.
The same heifer in early lactation requires a feed that is 63 percent total digestible nutrients and 10 percent protein, while the mature cow in early lactation requires a feed that is 55 percent total digestible nutrients and 9 percent protein.
Minimally, cattle should be sorted into three groups including 2-year-old heifers, old cows (10 years and older) and 3-year-olds, and cows ranging in age from 4 to 9 years old. Sorting beef cattle into proper winter feeding groups can reduce battles at the feed troughs, prevent the overfeeding and underfeeding of animals, and ensure that adequate levels of nutrition are provided to all animals in the herd.
Knowing BCS
Body condition scores of beef cattle allow producers to determine if the cattle’s nutritional requirements are being met and monitor nutrition programs. Body condition scores are an estimate of the amount of condition (degree of fatness) deposited on the body of a cow. The amount of condition on a cow is a direct reflection of her nutritional status.
The most common system used to evaluate cow body condition involves the use of a numerical scoring scale based on the amount of fat cover over a cow’s ribs, back, hooks, pins and around the tailhead. The numerical scale ranges from 1 to 9, with 1 representing extremely thin (emaciated) cows and 9 representing extremely fat (obese) cows.
Body condition of cows should be evaluated on a regular basis, and the scores should be used to make informed management decisions. It is suggested cows be evaluated every two months during the winter – and more often when extreme weather occurs.
Since there is a 60- to 85-pound range between condition scores, it is important to identify deficiencies early and make changes in nutritional programs. This will allow cows to bounce back and put them on track to achieve a target body condition score (5 for cows and 6 for heifers) for the upcoming breeding season.
The way in which a producer manages the task and cost of winter feeding will have a significant impact on the profitability of the beef cow herd.
Inventorying and analyzing feeds, identifying cows’ nutrient requirements, providing adequate amounts of water, sorting cows based on needs and body condition scoring cows are a few of the steps that can be taken to ensure that cows’ nutrient requirements are being effectively met during the winter. 
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J. Benton Glaze Jr.
- Extension Beef Cattle Specialist
- Animal and Veterinary Science Department - University of Idaho
- Email J. Benton Glaze Jr.
