Preparing Your Horse for Winter
By: Russell Mueller, M.S., P.A.S.

The crispness in the air signals the beginning of winter.  We prepare ourselves and our horses, by unpacking the sweaters and turning on our furnace.  But what do we need to do for our horses?  During the cold winter months, the management and diet of our horses needs to be adjusted as well. 

FORAGE-- Forage is the most important part of your horse’s diet.  This becomes even more critical during the winter season.  The breakdown of fiber in hay and pasture is accomplished by microbial fermentation in the horse's cecum.  This process releases fairly large amounts of internal body heat.  This increased heat from forage digestion can be a major factor in keeping your horse warm.  One thing to keep in mind, as hay intake increases, water intake will increase as well.  As the water decreases in temperature to the point of freezing, your horse may not be as willing or able to drink enough water.  Eating more hay, without getting enough water can increase the chances of impaction colic.  To help prevent this problem, make sure water sources are open and not frozen for long periods of time, so that water is easily accessible.  Other practices may be to add water heaters to prevent water from freezing, as long as the water heater is installed properly.  Even if the smallest electrical current is leaking into the water, horses may avoid the water, and therefore not drink enough.

INSULATION-- The horse’s hair coat is the first layer of insulation to cold temperatures.  Hair growth is controlled by the horse's hormonal system, which is dictated by daylight.  As the day length decreases starting in late summer, the horse will start to grow a winter coat.  As horse with a dry winter hair coat can remain comfortable in temperatures down to around 20°F.  However, horses with a wet or summer hair coat (maintained by artificial light) will start to become uncomfortable when temperatures reach 60°F.  Therefore, make sure your horse is put in an environment where their current hair coat can withstand the temperature.

                The second layer of insulation for the horses is its underlying fat cover.  The ideal body condition score for horses exposed to winter weather is 5.5 and above.  This body condition assures enough fat thickness to ensure proper insulation for the horse.  Going into the winter months, horses with less body condition than this should be fed to gain weight.  These horses need more calories so that body condition and corresponding fat thickness increase.  This can be accomplished by first increasing the forage portion of the diet.  However, poor quality hays may not supply enough extra calories.  In this case the concentrate portion of the diet must be increased.  The most common way to do this is to increase the grain portion of the diet such as oats, or one of the ProElite or Premium formula feeds.  Unfortunately, some horses may not handle the increased grain in their diet well.  In this case using a fat source, like Envision Classic, as a concentrated source of calories becomes a great option.  One pound of Envision Classic will give your horse the same amount of calories as 3 pounds of oats.  A common misunderstanding is that adding corn to the horses diet will make them warmer during winter months, probably because it is called a “hot” feed.  The digestion of corn does not increase the horse’s internal body heat generation, like forage does.  Corn will supply more calories and thus can increase the fat deposition and underlying insulation.  However, this can also be accomplished by other calorie sources as well like hay, oats, and fat sources. 

NUTRITION-- Beyond normal beyond function, the horses requirements for the remaining nutritional essentials such as vitamins, minerals, or protein do not increase during cold weather.  However, if they are deficient the body will not function at peak efficiency and therefore cause problems when making other adjustments.  Make sure your current ration is being feed at proper levels so that these essential nutrients are being supplied.

                The horse is very efficient in staying warm during the winter months.  Some simple adjustments to diet and management can further assure that they remain comfortable and happy, while we cannot wait until spring to arrive.  Best of luck with your horse.

Equine Nutrition Library