Ask the Expert: Estimating Winter Hay Needs

Question:  We recently purchased a farm and will be housing our two quarter horses over the winter; they will not ridden during the winter. Because I’ve always boarded my horses, I’m not sure how to estimate how much hay I will need for the winter.

Answer:  An adult horse at maintenance will consume between 2 – 2.5% of their bodyweight in feed (hay and grain) each day. For example, a 1,000 pound horse fed a 100% hay diet would consume 25 pounds of hay each day (using the 2.5% recommendation). From October 15 to May 15 (when there is no pasture in MN), the horse would consume about 5,350 pounds of hay or 2.7 tons. This would equal 107, 50 pound small square bales or six, 900 pound round bales during this time. For two horses, this amount would be doubled. It is critical to know the weight of the hay bales; not all bales weigh the same.

If the same horse was receiving five pounds of grain each day, their hay needs would be reduced to 20 pounds each day. From October 15 to May 15 the horse would consume about 4,280 pounds of hay or 2.1 tons. This would equal 86, 50 pound small square bales or five, 900 pound round bales during this time. Again, double this amount for two horses.

These estimates assume good quality hay is fed in a feeder to reduced hay waste. When feeding small squares-bales, hay waste when a feeder was not used (hay fed on the ground) was 13% compared to only 1 to 5% when a feeder was used.  When feeding large round-bales, not using a feeder resulted in 57% hay waste compared to 5 to 33% when a feeder was used. It’s always best to purchase extra hay to account for waste and because horses may require additional hay during the cold winter months.

This article is reprinted with permission from Krishona Martinson, PhD, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.

Cold Weather Care and Feeding of Horses

Horse in pasture during snow fall

Cold weather, particularly below freezing temperatures and cold rains, requires that owners pay careful attention to their horses to make certain that the horses maintain weight through the winter months.

First, make certain the horses are at least a body condition score of 5 or 6, meaning that the horses are carrying some fat cover over their ribs. Body condition should be monitored by physical examination at least monthly as long hair can hide weight loss. This is particularly important for older horses. The horses should also be kept up to date on dental care and overall health care, including appropriate deworming. It is a good idea to let horses go barefoot with proper hoof care during the winter.

Second, adequate water, above 40 degrees Fahrenheit, should be available at all times. If water sources freeze, the ice should be broken at least twice per day. Owners should NOT rely on horses eating snow for their water supply. A 1200-pound horse will require 12-15 gallons of water per day during cold weather. Having inadequate water available or water that is too cold for horses to drink comfortably may contribute to impaction colic. A horse that does not have adequate water available will also decrease feed intake, which may lead to loss of body condition. Salt should be available free choice, preferably loose salt rather than a salt block as horses may not lick a cold salt block.

Third, provide shelter from cold rains and wind. Horses remain remarkably comfortable in cold weather if they are dry and have shelter from the wind. Cold rains mat down the hair coat, reducing the insulation value of the hair and causing the horses to lose body heat.

Fourth, feed more! A horse’s digestible energy requirement increases for each degree below the thermal neutral zone. Wind chill increases the energy requirement also. Hay or high fiber products produce more heat during digestion than do grains, so adding extra good quality roughage to the diet is a good option. Grain intake can also be adjusted to maintain the desired body condition, but needs to be adjusted gradually.

  • A 1200 lb. horse at maintenance requires about 17.7 Mcal (17,700 Calories) of DE for maintenance.
  • Each degree C below Lower Critical Temperature (Anywhere from 5 degrees C or 40 degrees F down, depending on what the horse is used to.) increases DE requirement about 2.5%. (NRC, 6th Edition, page 10-11.)
  • Converting to Fahrenheit, each degree drop requires about 1.375%, so if the temperature drops from 10 degrees F to 0 degrees F, the DE requirement may increase 13.75% to 20.13 Mcal or 20,130 Calories.
  • This increase of 2430 Calories would require an additional 2.8 pounds of alfalfa grass hay to maintain body condition.
  • If the horse does NOT get the additional DE, the horse could lose a little over a quarter of a lb. per day.
  • If we have 3 months of cold weather, it is very easy for a horse to drop a full body condition score.

Proper winter care will help assure that your horse is ready for winter activities and is ready for spring when it finally arrives!