By Amy Radunz, UW Extension State Beef Cattle Specialist
Winter has come early in Wisconsin with snow and frigid temperatures. The cold temperatures, wind, rain, and snow can create stress and affect energy requirements of the animal. Cold weather can increase intake of cattle up to 30% due to increased maintenance energy requirements. For cow herds, this could mean cows are not able to eat enough feed to meet energy needs, especially when fed a low quality forage. For feedlots, caution should be taken increasing feed amounts during cold weather to prevent cattle from going off feed when warmer weather follows. As always in both types of operations, water is critical and should always be available, otherwise this could result in reduction of feed intake.
Tips for the cow herd
1. Provide higher quality forage or supplement energy with grain or by-products. With low to medium quality forages, the cow may not be able to consume enough feed to meet her energy needs during cold weather. Several studies have lead to the conclusion that for every one degree below critical body temperature a cow’s energy requirement (TDN) increases one percent. For cattle with a dry winter coat the critical temperature is 32 degrees F and with a dry heavy winter coat this temperature drops to 19 degree F.
Table 1. Example of effect of temperature on Energy Needs
|Extra Feed Needed|
|Temperature||Extra TDN Needed||Hay (lbs/cow/day)||Grain (lbs/cow/day)|
2. Feed thin and young cows separate and provide more energy. If not provided enough energy, this group of cows can enter calving in poor body condition, which can lead to difficulties calving, poor colostrum, lower milk production, and poor conception rates.
3. Provide simple windbreaks, shelters, bush, or bedding during cold weather to help cattle cope with cold temperatures. Hair coat provides insulation and the weather can impact degree of cold stress. Wet and or muddy conditions can decrease the insulation, because ‘air insulation; is less than those cows covered with snow. The air pockets between the hair fibers are a source of insulation and can actually decrease dry matter intake requirements. Therefore, be careful not force cattle into barns or enclosures during storms. These enclosures could result in wet and muddy conditions such as condensation dropping from the roof, which could increase cold stress and put cattle at risk for disease.
4. Feed cattle in late afternoon or early evening. Incremental heat production reaches its maximum 4 to 6 hours after feed is consumed, therefore feeding in the later afternoon or evening can provide higher amounts of heat from fermentation overnight when temperatures are the lowest.
Tips for the feedlot
1. Be careful not to increase feed delivered greatly during storms and cold weather. Cattle intake will increase during cold temperatures with feed bunks usually slick and feeders can easily get caught feeding cattle more than what cattle would be able to handle during normal conditions. Feeder should not make drastic adjustments to feed intake, because this could result in greatly reduced intakes or cattle going off feed after the storm passes or temperatures increase.
2. Try to stick to the same feed schedule. During winter storms, feeding can be delayed or missed, however be prepared and try not to let this happen. Ideally cattle should be fed with 15 to 20 minutes each day in order to maintain consistent intake.
3. Strategic use of bedding can help reduce stress. Increase bedding during cold temperatures. In open lots bedding should be placed on the slope downwind from prevailing winds. Thinner hided cattle (such as dairy beef) have less insulation and may require more frequent bedding than British-breed cattle.
4. Switch to afternoon or evening feeding. Research conducted at South Dakota State University reported greater heat production during the night when temperatures are colder and can help reduced cold stress in feedlot cattle.
These early winter storms may have caught some producers unprepared. Therefore having an back-up plan to keep cattle fed and access to water in frigid temperatures is important. Reducing the cold stress in cattle is beneficial, because cattle will more efficiently use feedstuffs, thus reducing feed costs to an operation.