During cold weather, the horse requires additional energy to maintain its internal body temperature and keep warm. The exact amount of energy depends on the severity and extent of the cold period. When environmental temperatures (including wind chill) drop below 0°C (referred to as the critical temperature), significant amounts of energy are used by the horse to maintain its internal body heat. For each 1°C decrease below the critical temperature, the horse requires a 1% increase in digestible energy to maintain a consistent body temperature. Wind chill, moisture, and coat thickness will affect the critical temperature. The horse’s thick winter coat has an insulating effect against cold and wind.
Due to the falling temperatures in winter, it inhibits the grass pasture to grow and it becomes rapidly depleted of natural forage. Horses must increasingly rely on their owners to provide them with a nutritionally adequate diet. To properly feed a horse during the winter months several key factors must be addressed: water, fibre and essential nutrients.
Water should always be the first consideration in the diet of any horse. An adult horse (500 kg) in a cool, comfortable environment that is not working or lactating requires a minimum of 25 – 35 liters of fresh clean water per day.
Impaction colic in horses during the winter months is one of our greatest concerns. This form of colic is mainly due to the horse becoming dehydrated because it consumes less water due to cooler temperatures (no sweating), cold water and a diet of hay (10% water content) instead of pasture (80% water content). When horses drink cold water during the winter, their bodies must expend additional calories to warm their tissues back up from the heat loss that is incurred, so they instinctively drink less.
Research has shown that horses drink the most water when the water temperature is between 7 and 20º C. Optimum water consumption will keep the fibre in the horse’s digestive system hydrated, allowing it to be broken down efficiently by intestinal bacteria and to be pliable, and less likely to “ball up” and cause a blockage in the large intestine. The water requirement is higher if the horse is in training, nursing a foal, growing, or pregnant.
Adequate fibre intake is the next consideration in feeding horses during the winter season. It is recommended that horses receive a minimum of 1.5% of their body weight in hay (fibre) per day. For a 500kg horse, this equates to 7.5 kg of hay per day. Horses can consume up to 3% of the body weight per day in hay (15 kg for a 500kg horse) if the hay is of good quality.
The fibre obtained from hay is necessary to keep the digestive system of the horse functioning properly. Without this hay fibre, horses will seek out other sources of fibre including bedding and wood fences or trees to satisfy their needs. Adequate fibre from hay is even more critical during the winter months since it is the feed ingredient that keeps horses warm during cold weather. Digestion and fermentation of hay produces heat that helps the horse maintain its body temperature during winter.
Unlike hay, consumption of grain does not produce large amounts of body heat during digestion. One problem that may arise with horses during the winter months is chronic weight loss. This can occur either by not feeding enough hay or by feeding poor quality hay to the horse. In both cases the horse will have trouble getting enough calories to maintain body weight. In the case of not feeding enough hay, the simple remedy is to provide all the hay the horse will consume during the day. If the horse is being fed all the hay it will consume and weight loss is still an issue, better quality hay must be fed.
Better quality hays typically contain higher calories for example alfalfa compared to grass hay. Other fibre substitutes include beet pulp. HYGAIN® FIBRESSENTIAL® and HYGAIN MICRBEET® are high in well-fermentable fibre and low in sugar, providing digestible energy between that of good quality hay and grains.
The protein, trace mineral and vitamin needs of the horse must be satisfied. Winter is a critical time to supply these nutrients since pasture, a good natural source of nutrients, is generally depleted.
The common source of supplemental protein, vitamins and minerals is from fortified feed concentrates. When choosing a feed concentrate you have to make sure, you are feeding the recommended amount. If you are feeding 1/3 of the amount recommended, you are getting exactly 1/3 of the intended nutrients for that type of horse. If you feel the amount of feed recommended is too much i.e. your horse is gaining too much weight you should feed a more concentrated product. These highly concentrated products, such as HYGAIN® BALANCED® an all-round pelleted balancer concentrate are designed to be fed at a much lower rate, but still provide the horse with adequate nutrients.
Strive to keep your horse in a good body condition prior to winter months as the extra body fat provides an additional insulating effect against wind and also serves as an energy reserve. Increasing forage and concentrate will be necessary in horses of poor condition. Increase the dry-matter content of the diet 24 hours prior to forecasted cold conditions. Supplementing fat is beneficial to increasing the energy density of concentrates. HYGAIN® RBO® – Equine Performance Oil® is a unique blend of pure rice bran oil, omega essential fatty acids and natural antioxidants formulated for all horses.
Older horses and those in poor condition have additional needs during the winter. Starting them on a high caloric diet in the fall can help them maintain weight during frigid weather. Look for one with a fat level of 7% or more such as HYGAIN TRU CARE® and HYGAIN® EQUINE SENIOR®, as it will provide the extra calories needed to keep these horses from losing weight during the winter.
Winter is also the time when the stable may be “closed up” in an effort to make the environment warmer and less draughty for the horse. Good ventilation is more important than providing a little more warmth, so be sure to provide good air flow in your stable even in winter time.