WINTER FEEDING CONSIDERATIONS FOR HORSES
Karen E. Davison, Ph.D., Purina Mills, Inc.
Cold weather presents horsemen with some specific nutritional considerations. As winter approaches they must evaluate their horses and feeding programs to insure that the horses get through the cold weather in good shape. This is particularly important for horses kept in pastures or paddocks, exposed to cold weather, but there are also considerations for stabled horses at this time.
All warm-blooded animals, including horses, have a critical temperature. This represents the temperature below which a horse must produce extra heat to maintain its body temperature. Mature horses in good flesh, where ribs cannot be seen, have a critical temperature around 30˚F during early winter. After developing a winter coat and gaining 100 pounds, the critical temperature may be reduced to around 15˚F. It is estimated that young horses, horses in thinner condition and those that have been stabled and not developed a winter coat, may have a critical temperature around 40˚F. When wind or wet conditions are present, the critical temperatures will be
higher as well. In order to produce extra heat, an increase in feed energy is required. Horses will require an estimated 15 - 20% more feed for each 10˚F the ambient temperature falls below critical temperature. However, thin horses or horses with short hair may need even greater increases in dietary intake to maintain normal body temperature.
Both body condition and feeding program affects the extent to which horses can deal with severe weather. Therefore, it is important that horses come into winter carrying extra condition. The additional body fat serves as insulation and energy reserves in times when the thermometer dips below the critical temperature. Once cold weather sets in, it is difficult to put weight on horses. Thin horses get colder and use so much energy trying to stay warm, there often aren't enough calories left for weight gain.
Young horses and broodmares in late gestation, may not be able to consume enough of a high roughage diet, such as hay, due to restrictions in digestive system capacity. These horses must have access to good quality, highly digestible feeds in order to meet the additional energy requirements due to cold weather and higher production levels.
Over the years, many horsemen have changed their rations from summer to winter to accommodate some of these needs. Typically, this has involved increasing hay feeding and changing from oats to corn or a sweet feed in the winter. Feeding additional hay provides extra calories and also helps maintainbody temperature due to the internal heat produced during digestion of fiber. The change from oats to corn or a sweet feed is based on the impression that corn or sweet feed is a "hotter" feed than oats. This concept of oats being a summer
feed and corn a winter ration has some merit, but also has some flaws.
Nutritionally, oats and corn compare as
follows:
Fiber,% Protein,% Calories/lbOats 10.7 11.8 1200
10.7 11.8 1200Corn 2.2 9.0 1500
2.2 9.0 1500One pound of corn has more energy and is lower in protein and fiber than one pound of oats. Quality and moisture content of the grains will affect this somewhat, but the trends will remain the same. Not only does corn have more energy per pound than oats, corn also weighs more per unit of volume. One coffee can full of corn has about 45% more calories than the same coffee can full of whole oats. So if a horse goes from one can of oats to one can of corn, his energy intake is increased by about 45%. This has led to the idea that corn is a "hotter" feed than oats. Actually, because of the higher fiber level in oats, oats produce more internal heat during digestion than does corn.
Corn or oats alone can provide adequate calories but not adequate protein, vitamin and mineral intake. The best
option for the horse year-round is to feed a high quality, balanced diet of good quality hay and a high-quality, fortified commercial feed. During the winter months, provide as much shelter as possible, especially from wet weather, and increase feed intake to help maintain body condition. Then as warmer weather arrives, the best plan would be to continue to feed the nutritionally balanced diet, simply reduce the amount fed. When a nutritionally balanced feed is used, the only adjustments necessary are to increase or decrease the amount fed. These adjustments should be based on the body condition of the horse or in anticipation of changes in energy demand. Some horse owners increase the amount of hay offered to horses during winter months. This can help keep them warmer, due to the increased internal heat produced during the digestion of roughages. Hay intake may be decreased during summer months but horses should consume a minimum of 1% of their body weight in hay, regardless of the season.
One additional, very important consideration for nutritional management of horses during the winter is water intake. Mature horses in temperate climates will normally drink from 5 - 8 gallons of water per day. Increasing the amount of hay in the diet will increase the water consumption, up to 9 or 10 gallons of water when horses eat an all hay diet. In the cold winter temperatures with water getting cold or freezing, water intake can decline dramatically. Increased hay intake combined with decreased water intake can potentially lead to impaction colics. In cold weather, water should be heated to 45˚F to insure adequate intake and adding one or two ounces of salt to their feed may also stimulate water consumption.
