Winter Nutrition

Published on Fri, 09/25/2009 - 12:36pm

 Feed is the single highest production expense for most beef operations. Cattlemen should take steps now to ensure they have adequate resources to fully meet their herd’s winter nutritional needs at the lowest possible cost.
Assess Your Herd
Whether an operation is big or small, estimating its feed requirements begins with understanding the makeup and body condition of the herd. “It’s important to evaluate body condition score,” says Russ Euken, a Livestock Specialist with Iowa State University Extension.
The most commonly used assessment tool is a nine-point scale, with one representing extreme thinness. Euken says the goal for most herds is to have cows scoring about five headed into winter.
Weather-induced stress, higher feed costs and greater labor demands for feeding make it more difficult and costly to improve body condition in the winter. Weaning calves in a timely manner and getting thinner cows on a higher-energy ration in the fall often pays dividends later.   “If they’re thin, it’s a lot cheaper to get that score up where it needs to be before we get into that cold weather,” Euken says.
Depending on feed costs and availability, market prices, and space constraints, cattlemen may wish to consider trimming their herds heading into winter, Euken suggests. “If we’ve got higher feed costs or a shortage of feed, one strategy would be to do culling.” Eliminating thin, open or poor-producing cows increases the feed efficiency of the overall herd, reducing costs and helping to extend limited feed supplies.
Although there are differences among individuals, as a general rule larger and heavier animals will require more feed. Age, sex, and breeding vs. market status have an even greater impact on nutritional needs. 
Mature bred cows in good body condition need to maintain that condition while providing for the gestating calf. First-calf heifers must meet their gestational needs while still progressing towards full musculoskeletal maturity, while growing heifers have (obviously) a lot of growing to do. Protein and energy requirements for the latter two groups may be greater even as their smaller body size enables them to consume less total feed.
With cattle destined for market, producers may choose to sell calves at weaning, background calves on a diet with sufficient energy to allow about two pounds of gain per day, or fully finish the cattle on a high-energy diet permitting gains of 3-3 ½ pounds per day. The latter approach “has traditionally been most profitable,” Euken says, “primarily because we’ve had a history of cheap feed.” Individual producers must consider current feed prices and availability, labor costs and availability, market forces and risk tolerance (among other factors) in developing a strategy to meet their needs.
Given the significantly different nutritional requirements for various animals within a herd, feeding the animals as a single unit is highly inefficient from a feed-utilization standpoint. Doing so ensures that either some animals will be overfed or others underfed, if not both.
Market animals are generally kept separate from breeding animals. Euken suggests cows should be further segregated into a minimum of two groups, one consisting of well-conditioned mature animals and the other containing heifers and thin cows. Depending on space and labor issues, further efficiency can be obtained by separating growing and first-calf heifers as well as by segregating animals based on temperament and body condition. 
Assess Your Feed
Having determined the size and general needs of their herds, producers should next consider the price and availability of various nutrient sources. “Do a feed inventory, and match that up to cow needs,” Euken suggests. “I encourage producers to look at what they have on the farm and determine if it meets their needs.” 
Cattle can adapt to a wide variety of feed types and to various qualities of feed provided ration changes are introduced gradually. “There’s some area every year that has poor-quality forage,” Euken says. “A beef cow herd is a good place to use it. You just have to know what you’ve got.”
The only way to know what you’ve got, according to Euken, is to test it. He strongly encourages producers to perform forage testing. Whatever your primary feed source, knowing its nutrient content is essential to developing a balanced ration.
Potential feeds must be assessed with regard to energy content, protein content and vitamin and mineral content, normally in that order of priority. By testing their feeds, producers can determine what additional resources they will need to purchase to meet their herd’s requirements in the most economical manner.
A producer with an adequate supply of high-quality hay might not require a large amount of grain. Another who depends heavily on lower-quality forage may need to provide significant additional nutrients. Fortunately, there are many ways to obtain them. “The cheapest sources in this part of the world are corn and distiller’s grain,” Euken says.
When baled corn stalks, lower-quality hay or similar forages are available at low cost, utilizing them along with supplemental nutrient sources is often a sound strategy. Feeding corn stalks in conjunction with distiller’s grain works particularly well for many producers in the Upper Midwest, Euken notes. 
While there is some concern among cattlemen about sulfur concentrations in distiller’s grain, Euken believes this isn’t normally a significant issue. “In cow-calf herds we’re typically not feeding enough concentration of distiller’s grain to be a problem.”
For producers in areas where corn and distiller’s grain are less readily available or more expensive there are several other non-traditional options. Whey, beet pulp, whole cottonseed, potatoes, almonds, corn sugar, canola meal, linseed meal, soy hulls, sweet corn silage, bakery by-products, candy and even food-grade alcohol have been incorporated into feeding systems in various parts of the country. Individual cattlemen must consider price, availability, transportation and storage issues, labor costs and convenience when evaluating alternative feeds.    
While many producers base their rations on feeds they produce, there are situations where what’s at hand isn’t the most economical feed option. For instance, cows on pasture or in harvested grain fields in the fall and early winter may not require supplemental feed at all beyond mineral blocks. Even those completely dependant on stored feeds may not need the highest-quality forage. In such cases a cattleman with an excess of high-quality hay might do well to sell at least part of his crop and purchase alternative feeds such as lower-quality hay or baled corn stalks.
Assess Your Operation
Operational issues affecting feed efficiency, and thus total cost, go well beyond the quality of the feed itself. Appropriate feed storage, efficient feeding practices and optimal cow care all reduce waste and boost feed utilization.
Feed storage considerations begin at the time of harvest. “Poor harvesting and storage management can lead to a 20-25% loss on both hay and silage,” Euken says. Hay, silage and haylage must be harvested at correct moisture levels to ensure maximum nutrient retention and prevent spoilage.
Ideally hay and silage should be stored under roof, but in many cases this is not feasible. Silage or haylage stored outside should be covered, tightly packed and accessed so as to minimize daily environmental exposure. Round bales should be net-wrapped or similarly covered. All forage stored outside should be placed on cement slabs, rock, tires or similar barriers to reduce spoilage and ground loss.
When forages are fed on the ground significant loss can occur due to trampling and bedding use. Feeding in well-kept bunks or hay rings helps to minimize this loss. Limit feeding further reduces loss by ensuring that the majority of feed will be consumed when it’s provided. However, limit feeding does require greater producer effort and adequate feeding space. “Our traditional way of putting big bales out and letting them eat on it for 2-3 days creates more waste, but less labor,” Euken says.
Most producers utilize a strategy of feeding lower-quality forages early in the winter and saving their best feeds for the late gestational period, where energy needs are greater and consumptive capacity is somewhat decreased. Yet getting cows to eat enough low-quality forage can be challenging, Euken says. “Feed one bale of hay and two of corn stalks, and the cows will be standing at the fence bawling (for more hay) with the two bales of corn stalks.”
To increase palatability and consumption of lower-quality roughages, many producers combine feeds in a total mixed ration. This strategy requires access to a feed grinder, adequate feed delivery equipment and additional labor. Cattlemen must consider equipment costs, labor costs and convenience when evaluating this option.
Cold, wet conditions can significantly increase the metabolic needs of cattle. Producers cannot control the weather, but they can provide adequate shelter and bedding while continually monitoring cow condition. 
Access to fresh water is critical regardless of the season. Keeping tanks open and water lines flowing in winter can sometimes be a challenge, but it’s one the producer must consistently meet.
Putting It All Together
With so many variables to consider, how can producers develop a feeding strategy that meets cow needs while minimizing cost? Fortunately, there are many tools at the cattleman’s disposal.
Feed companies normally employ nutritionists who can assist with ration development. Most states have some type of extension service from which producers can solicit expert advice. ISU Extension also offers computer software to help producers evaluate various feeding options.
With the Beef Ration and Nutrition Software (BRANDS) program, producers can enter variables such as cow body condition score, age, pregnancy status, coat condition and so on to assess animal nutrient needs. When various potential rations are plugged into the system, the software calculates the percentage of those needs being met by the ration, as well as its cost.
“With costs where they’re at today,” Euken says, “we should be able to feed a cow for $1 to $1.20 per head per day.” He notes, however, that feed costs and availability are subject to change. The successful producer must be willing to change with them. 
Although feeding strategies may vary, Euken notes, the goal remains constant: “Feeding the cheapest way you can while meeting the needs of the cow.”
More detailed information about sound beef herd management is available from the Iowa Beef Center at
Russ Euken
Russ Euken is a Livestock Specialist with Iowa State University Extension and is based out of the Hancock County office in Garner, Iowa. He has been with ISU Extension for 29 years, including 16 years in his present position. Serving the North Iowa area, Euken works primarily with beef and swine producers. His areas of expertise include nutrition, cost-efficiency, economics and general production issues. Euken holds a B.S. in Animal Science and a master’s in Ag Economics, both from Iowa State University.