We have had a great winter so far, with dry but warm weather making it easy for our cows out in the elements, but a winter storm is predicted in Oklahoma later this week. Cows need to get adjusted to cold temperatures over time and grow a thick winter haircoat to be acclimated before winter storms arrive, or they will suffer from cold stress and require extra care. Body condition of cows and their hair coat can play a large part in their tolerance to colder conditions. What do we need to do to get through this week’s arctic blast?
Consider the Cow.
Cows in good body condition, those with body condition scores of 5 to 6, with good thick winter hair coats have a lower critical temperature around 32° Fahrenheit. Thin cows with thin hair coat are at more risk to cold stress with lower critical temperatures of around 40° F, while cows with wet haircoat have lower critical temperature of 59° F. For each degree below the lower critical temperature energy requirements increase by 1%. With wind chills down to expected to get below 0° F, maintenance energy requirements will increase by up to 30 to 40%.
How much more feed?
Let’s use a 1,200-pound cow in good body condition that needs 2 pounds of supplemental 20% range cubes to meet her requirements in normal conditions as an example. When temperatures get down to 20°F her requirements increase by 12%, to meet the shortfall in energy she will require 3 pounds of additional cubes per day for a total of 5 pounds of cubes per day.
If we consider a thin cow with a thin hair coat, it gets to be more critical. She is already needing to gain body condition to increase her chances of rebreeding for the next calf crop so we should already be feeding around 4 pounds of cubes a day. Her lower critical temperature is 40° F so, when temperatures fall to 20°F her requirements increase by 20%. We will need to provide 7 additional pounds of supplement for a total of 11 pounds of supplemental feed daily. Feeding this much supplement is expensive and hard to manage.
Water is Still Important.
Northwest Area Livestock Specialist Dana Zook summarized the water needs for cows during cold weather in a previous article (https://extension.okstate.edu/programs/beef-extension/cow-calf-corner-the-newsletter-archives/2024/february-12-2024.html). Feed intake is tied to water consumption. Access to clean fresh water is always essential. Water is essential to feed digestion. Limiting water decreases passage rate of feeds which will in turn compromise feed intake, making it very hard for cows to maintain weight. Another factor that affects water needs is the stage of production. The need for water increases with the demands of production. For example, lactating cows require more water than dry pregnant cows. Dehydration is an added stress and cows deal with winter stress better when we ensure they have adequate water.
Other Considerations.
This week’s arctic blast can create significant dangers for animal health and production. OSU Extension cold-weather recommendations include:
- Make sure cattle have access to as much hay as they want to eat. Ruminal fermentation helps keep the animals warm.
- If increasing concentrate supplementation rates to help offset energy deficiencies it is best to provide feed concentrate supplements every day.
- Provide a windbreak to lower the animal’s cold stress.
- Unrolling low-quality hay as bedding will provide some relief from the extreme temperatures.
Paul Beck discusses management of cattle in cold weather on SunUpTV from February 6, 2021 https://video.okstate.edu/media/Cattle%20%26%20Cold%20Weather%20(2_6_21)/1_vca5rntt and February 20, 2021 https://video.okstate.edu/media/Cattle+%26+Extreme+Cold+%2802+20+21%29/1_83wk2akr .
