Cold Weather Feeding for Horses

 In order to maintain internal body temperature and keep warm a horse requires additional energy during cold weather. The exact amount of energy depends on the severity and extent of the cold period and individual characteristics of the horse. When environmental temperatures including wind chill drop below 45 degrees Fahrenheit F or seven degrees Celsius C called the critical temperature significant amounts of energy are used by the horse to maintain its internal body heat.
The amount of energy required by the horse to meet daily energy needs is measured as digestible energy DE in calories. The critical temperature can be used to estimate increased energy needs which the horse must obtain from its diet. For each degree F decrease below the critical temperature the horse requires a one percent increase in DE to maintain a consistent body temperature. Wind chill moisture and coat thickness will affect the critical temperature. The horses thick winter coat has an insulating effect against cold and wind. However if the coat becomes wet the hairs insulating properties are lost and the critical temperature will increase by 10 to 15 degrees F.

Adjusting Energy Intake
By knowing weather conditions along with the properties of your horses daily ration you can adjust energy intake accordingly. For example for an 1100 pound horse at maintenance where there is a dry environmental temperature of 30 degrees F with a wind chill that results in an actual temperature of 25 degrees F the steps would be as follows
Step 1 Subtract the actual temperature including the wind chill adjustment from the critical temperature 45 degrees F 25 degrees F 20 percent increase in DE requirements. In this example it is dry but remember to add 10 to 15 degrees to the critical temperature to account for wet conditions if necessary.
Step 2 An average 1100 pound horse at maintenance requires 16 4 Megacalories Mcal of DE per day. Multiply as follows to calculate how many Mcal increase is needed based on the 20 percent requirement shown above 16 4 Mcal x 20 percent 3 28 Mcal increase. The requirement thus increases as follows 16 4 Mcal 3 28 Mcal 19 68 Mcal DE per day.
Step 3 Next you need to determine the amount of feed necessary to supply these increased calories. An 1100 pound horse typically consumes 19 pounds of ration daily or 1 7 percent of his bodyweight. Because the recommended DE level