Adequate nutrition helps maintain cow condition during winter

Published on Wed, 11/01/2017 - 12:10pm

Adequate nutrition helps maintain cow condition during winter

By Lisa Pederson, Dickinson Research Extension Center

Feed Intake
Voluntary feed intake of beef cattle increases with decreasing temperatures. Table 1 describes the proportion of increase in intake for decreasing temperature ranges. Cattle consume 105 to 110 percent of predicted intake when temperatures drop below 22 F and up to 125 percent of predicted intake below 5 F (NRC, 1981). During severe cold (wind chills of minus 20 F or lower) intake actually may be reduced because cattle are reluctant to leave sheltered areas. Feeds with higher digestibility, that is, better-quality forage, should be fed during severe cold so cattle can compensate somewhat for increased energy needs.
A rule of thumb is to increase total digestible nutrients (TDN) 1 pound for every 5 degrees below zero F. Another version is to increase TDN 1 percent for every degree below the lower critical temperature, which in some cases with a dry winter coat may be as low as minus 6 F (NRC, 1981) for gestating beef cows adapted to winter conditions.
While many factors influence voluntary forage intake, for planning purpose, cows may consume as little as 2.5 percent of their body weight as hay under mild conditions but may need to be provided up to 3.5 percent during severe cold. Waste could increase the amount considerably.
Less than adequate feed intake and nutrient content of rations for pregnant beef cows could have short- and long-term consequences. Thin cows may be weak and have a difficult time calving, and they may not produce high-quality colostrum, affecting calf health. Calf vigor and rebreeding may be compromised as well. Fetal programming research suggests that cows fed less than adequate protein during gestation produce calves that may not be as healthy or productive throughout their lives.

Various forages are used as the primary feed source for wintering cows. Better-quality forage should be offered during the winter to keep cows in condition. Supplementation often is necessary to meet nutrient requirements of the animals when low-quality forage is fed. Extended periods of severe cold can reduce cow condition, especially if cows are in marginal condition and the ration is not formulated for the severe conditions. Cows can starve to death on a full stomach if forage quality is low and no supplements are offered. Impaction can occur, resulting in loss of rumen function and, potentially, death. If low-quality forage is the primary feed, supplemental protein and energy likely are needed.
Take samples of each forage (see “Sampling Feed for Analysis,” NDSU Extension publication AS-1064, Schroeder and Sedivec, 2010) and send the samples to a reputable laboratory for analysis so you know what nutrients are in your feed and you can add specific ingredients to balance the ration. Assistance with ration formulation is available through your county Extension office or from feed companies.
Frozen feed requires significantly more energy to warm than wet feed, such as silage or distillers grain. Frozen feed must be thawed and warmed to body temperature. The effects of ingesting frozen (or cold wet) feed on rumen microbes and digestive function are not well defined.

Interval Feeding
Nutrient-dense feeds, such as silage, coproducts, grains and minerals, may be fed once every two days because preliminary research suggests cattle performance and rumen function are not affected negatively. Preliminary studies also suggest that lower-volume supplements (1 to 2 pounds per head per day) may be fed every third day without affecting rumen function. As an example, if cows are fed 2 pounds of a supplemental feed daily, feeding every third day means providing 6 pounds per head. More research is under way to evaluate interval feeding for gestating beef cows. Nutrient requirements in the third trimester of pregnancy increase, so intervals longer than two days may not be advisable without further research.
Another labor-saving technique is to pre-position forage in separate pens to reduce the frequency of starting tractors or loaders. Separate adjoining pens will be required for this practice. Feeding chores may be reduced to opening a gate every day or two. Pre-positioning bales once per week may be possible, depending on pen space, feeding arrangements and number of cows.
Grazing a multiday supply of bales in a field feeding setting (either set out periodically or allocated by temporary fencing) is gaining popularity to minimize feeding costs. To ensure the opportunity for cows to eat to their fill, meet nutritional requirements and control waste, a sufficient number of bales of known or estimated weight must be provided. Feeding waste can be controlled by the amount of feed provided and by using a mix of bales of higher- and lower-quality forage. Higher-value and higher-quality hay will be consumed with little waste, whereas some of the lower-quality forage of minimal value may be left as residue and used as bedding.

Sorting Cows
Cows should be sorted by nutrient requirements and fed according to need. This practice will optimize feed use and minimize overconditioned animals while permitting thin cows to recover without significant competition. Where limited lots or feeding areas will not accommodate grouping the herd by age and condition, at a minimum, a separate pen should be set aside for high-need animals lacking condition, thriftiness or soundness where competition is minimized and better feed can be provided. First-calf heifers and older, thin cows may be fed together with well-conditioned mature cows fed lower-energy diets appropriate to their production stage. Heifer calves kept for replacements will not compete well with mature cows and should be fed separately.

Time of Feeding
Feeding cows late in the day during severe cold will increase heat production during the night by the activity of eating and ruminating. Feeding cows at night also may alter the time cows calve, with as many as 85 percent of calves born between 6 a.m. and 6 p.m. when cows were fed between 5 and 10 p.m. (Anderson, 1982).

High-concentrate Diets for Emergencies
If the availability of forage is limited during severe storms, cows can be fed diets that are primarily grains or coproducts, but producers should manage carefully and understand the effects on the rumen. Feed must be distributed so all cows have equal access to avoid boss cows consuming more than their share and potentially experiencing acidosis. This practice runs some risk of nutritional problems.
Grains should be fed whole to reduce the rate of fermentation and acidosis potential. High-fiber feeds, such as wheat midds, soy hulls, barley malt or beet pulp, are preferred to grains due to low starch content and reduced acidosis potential. Distillers grain contains high levels of fat and sulfur and should not be fed as the sole feed ingredient. Careful planning and an extended adaptation period are recommended if high-concentrate diets are to be fed to beef cows in the winter.

Cattle should have adequate amounts of clean, fresh water available at all times. Most automatic water fountains operating on a pressurized water system require energy to keep them from freezing. Energy-free fountains may be useful if more cows drink consistently and water from deeper wells enters the fountain at a higher temperature. Clean water fountain basins often and check water temperature to ensure thermostats are working and not drifting to higher temperatures.
To reduce the energy use of commercial water fountains, consider adding more insulation inside the housing, and cover the concrete slab inside the fountain as well. Rigid-board insulation cut to fit is recommended because it does not absorb water. The water line rising to the fountain from the buried lateral line should be centered inside a 10-inch or larger diameter insulated casing that extends 10 feet into the ground and acts as a heat well. Insulating the outside of the casing during construction where it passes through the concrete slab will reduce frost penetration. Steamfitters insulation may be useful for the riser pipe inside the casing, or a small light bulb may provide enough heat to keep pipes from freezing. Consider covering the exposed water surface with an insulated float, but secure it with a chain or cows may toss it out.
The “Beef Housing and Equipment Handbook” (1987) states that 16 head of cows can drink per foot of water fountain or tank perimeter when cows are in a pen and have continual access to water throughout the day. Practical experience suggests this is a conservative number if water flow is adequate.
Snow may be considered a water source in an emergency if it is soft and fluffy and not crusted or icy. However, some animals may not adapt to eating snow and suffer from dehydration. Also, thawing and heating melted snow to body temperature reduces cows’ energy resources. Little research or information is available on snow as a water source.

Health Considerations
Extreme winter weather can result in hypothermia and ultimately cause death. Cattle that suffer hypothermia or frostbite are more prone to other disease conditions and certainly do not perform as well as cattle that are warm, dry and out of the wind.
Treating sick animals in the cold poses a challenge for personnel and products. When transporting or using any veterinary product, vaccines and medications should be kept in a “warm box” with a temperature from 35 to 45 F (2 to 7 C) when used. Frozen vaccines can become denatured, and frozen antibiotics can precipitate in the bottle. A portable heat source or more permanent chute-side heated and well-lit compartment on top of a work bench or cabinet works well to safely handle syringes and sharp objects such as needles, prepare correct dosages, and keep ear tags warm and pliable.

Sort cows close to calving into a more accessible facility for easier observation and addressing problems. A simple headgate-and-panels setup inside a lighted shed area is useful for solving dystocias. A calf warmer may be useful if cows are calved during severe weather (see photo). Small pens for short-term housing to ensure cows mother and calves nurse are very helpful in the shed with the headgate.
If possible, move cows that have calved to a new pen or yard to alleviate any issues with claiming newborn calves. This also will help maintain a healthy environment for newborn calves.
Crowding of baby calves in bedded shelters may increase the spread of scours or respiratory disease. Frequent checks, moving shelters and providing fresh bedding help reduce these challenges.
Calving cows in the winter may result in frozen ears or tails, which is more of a cosmetic issue that does not have an effect on performance. Frozen teats can be a challenge until calves are a few days old and capable of consuming more milk.
Winter calving is hard work for producers, family members and hired hands. Frequent checks of the close-up cows, especially during winter storms, as well as the care of newborns and the all too frequent problems require continual effort. Stress from little sleep, long days and frustrations of calving can be detrimental to personal health. Train all involved to recognize normal calving and when intervention is needed, as well as other calving management practices. Rotating night checks and chores helps all hands own the calving process and learn more about what needs to be done.