Evaluating feeding strategies for the winter
Cattle are relatively less sensitive to the cold when compared to other domestic animals. This hardiness is due to their large size, their usually effective thermal insulation through thick haircoats and extra fat, and the amount of heat they produce through normal digestion and metabolism. In particular, cattle that are already acclimated to the cold are able to increase their metabolisms to prevent hypothermia during periods of severe cold stress.
However, not all cattle have this ability, at least not to a sufficient extent, either because they are not accustomed to extreme cold or because of variations in age or breed. By taking some simple steps, producers can help their cattle stay comfortable, healthy and productive through the long winter days and nights to come.
Feeding for maximum cold protection
Dairy cows, for instance, must maintain a core body temperature of around 101 degrees. Cold stress occurs when the weather gets cold and a cow’s metabolic processes are not enough to keep her temperature at 101. When this occurs, the cow will divert her energy to maintain a normal body temperature, and this leaves less energy for essentials such as weight maintenance, reproductive function and milk production.
In fact, a USDA study has highlighted that maintenance energy requirements for lactating cows increase by a full 50% when the temperature falls from freezing (32°F) to 0°F. It is not uncommon for cows to require an additional 20% more feed during cold weather (Table 1) to maintain body condition and productivity and to ward off illness. This is especially true because they naturally add a layer of fat as insulation, and this requires a higher caloric intake.
Table 1. Temperature effects on dry matter intake in cattle
Cows commonly increase feed intake naturally as outside temperatures fall, and that increase in intake will typically cover most of the extra energy needed to cover increased maintenance requirements. However, in extreme cold, dry matter intake does not increase at the same rate as metabolism, so animals are in a negative energy balance and temporarily shift energy use from productive purposes to heat production. Additionally, in extreme cold, dry matter digestibility can be lowered due to an increased rate of passage of feed through the digestive tract.
And so, while increases in feed intake can go a long way in maintaining core body temperature, providing extra feed is not enough; rations should also be formulated to meet increased cold-weather requirements. For instance, slight increases in energy inclusion (starch, sugar and/or fat) during this time can help to moderate energy losses due to lower intakes.
The research-proven feed technology Yea-Sacc® 1026 BAC can also be of help here. Supplementing Yea-Sacc 1026 BAC supports the entire GI tract, helping to condition the rumen for optimal efficiency while optimizing nutrient digestibility and minimizing the growth of undesirable organisms.
Keeping feed and water warm, safe and accessible
One issue that is not often considered during winter is the impact of cold temperatures on the feed that cows are consuming. Wet forages and byproducts can freeze during long stretches of very cold temperatures, resulting in chunks of feed and sorting at the bunk. This can lead to reduced intake. Also, when cows do consume frozen forages, they must work harder to warm up that TMR, and this requires additional energy. In winter, be careful to prevent feed from becoming wet and freezing. Feed bunks should also be monitored more frequently to ensure that feed is pushed up and that intake potential is being met with adequate feed delivery.
Frozen water or even excessively cold water can also cause problems. Cows can drink three to five gallons of water per minute, and the water supply needs to keep up with demand. Also, cows prefer water between 40° and 65°F; if the water gets much colder than 40°F, water intake and dry matter intake can both be reduced. To ensure safety and adequate water intake:
- Check regularly to ensure that waterers and water tanks are not frozen.
- Check tank heaters and waterer heating elements to ensure that they are in good working order and properly grounded, to minimize the chance of stray voltage.
- Check the area surrounding the waterer to ensure that it is free from ice, which may deter cows from visiting it because of the risk of slipping.
Prioritizing warm, dry housing
Of course, housing type and environment are a major factor during cold weather as well. For instance, a thick haircoat offers significant protection against the cold, but cows housed in tie stall barns will not have the same thick, long haircoats as cows in free-stall barns or cows with access to the outdoors during winter months. Whatever their housing situation or physical condition, however, cows should be kept warm and dry to help them maintain an adequate core body temperature.
When evaluating housing options in winter, be sure to keep wind chill in mind (Table 2). Protection from the wind is vital to keeping animals warm in cold temperatures.
Table 2. Wind chill temperatures based on air temperature and wind speed
Providing increased nutrition and caloric intake, adequate access to water, and protection from environmental conditions during cold weather is crucial to maintaining your cows’ comfort, health and performance. Take steps now to be ready for the coldest part of winter in the U.S. For more details on protecting your cows and your productivity in winter, contact your local Alltech representative.