Feeding horses during the winter months can often be challenging. For the last few years, UK winters have been mild and wet, but as soon as temperatures drop for a consistent period, the growth patterns of grasses are affected meaning there here is little or no nutrition left in the grass. For those horses kept at grass full-time and for those turned out for periods of the day, their grazing requires supplementing with alternative forms of forage.
Forage (or fibre, such as grass, hay or haylage) should form the basis of any horse’s ration at any time of year. In their natural environment, a horse would spend approximately 18 hours a day foraging, rarely fasting for more than 2 – 4 hours at a time. Saliva is generated in response to extended periods of chewing and this in turn helps to buffer the gastric acid, which is secreted continuously into the stomach. In addition, natural living conditions encourage the horse to move freely, which is believed to assist with the normal movement of stomach contents through the gastrointestinal tract.
Ensuring suitable levels of forage intake is therefore essential for gastro-intestinal health, but equally important, forage plays a thermoregulatory and nutritional role for the horse. Horses are ‘endothermic’, meaning they can produce heat through metabolic processes in their body, enabling them to maintain their average body temperature (Frappell et al., 2008).
Thermoregulation – Heat Increment
Metabolic processes, including heat provided from nutrient metabolisation, maintain a horses body temperature.
The equine gastro-intestinal tract is unique, in that enzymatic digestion occurs in the foregut, whilst fermentation occurs in the hindgut. The equine hindgut is resident to a vast population of microbes or microbial population, that break down, or ferment, fibre-based feeds. This fibre is converted into ‘volatile fatty acids’, which are then absorbed and utilised by the horse’s body. As a by-product of fermentation, metabolic heat is generated – helping the horse stay warm from the inside out and supporting thermal comfort. (Santos et al., 2011) It is worth noting that feeds that are high in grain (starch), on the other hand, are ultimately, the reverse of forage and do not produce metabolic heat as a by-product (Merritt et al. 2013). We refer to this as ‘heat increment’ and fibre-based feeds have a higher heat increment than low-fibre feeds, such as grain. (Julliand et al. 2004).
Nutritional Requirements
Current recommendations are to feed approximately 2 - 2.5% of the horse’s current bodyweight (BW) in forage per day. (Maintenance diets should involve around 2% of a horse’s BW per day, whereas older or growing horses should consume 2.5% of their BW on a daily basis). As an absolute minimum, it is recommended to provide at least 1.5% bodyweight per day.
Good quality forage contains a number of nutrients and may be capable of providing enough Digestible Energy (DE) for healthy horses in maintenance or light work. It is also worth noting that fibre provides slow-release energy (Hervik et al. 2019), so can be ideal for horses that can become over-excited.
Harper et al. (2004) estimated an increase of 10-15% good quality forage to be fed when temperatures drop below freezing level (0℃). Ideally, an unlimited (ad lib) supply of forage fed at ground level is the best way to meet a horse's behavioural and nutritional requirements during winter when there is an increased demand for heat production. However, this system may not be appropriate for all horses. An overweight horse would benefit from a restricted intake due to weight loss; so, in this case, their daily requirement intake can be spread out throughout the day with lower digestible energy fibre feeds being provided, such as soaked hay.
On the other hand, for young, old, thin, or performance horses who are more vulnerable to winter temperatures, or have a high energy output due to exercise, forage alone may not be sufficient to keep them in top condition (although it should always form the foundation of their diet). In many of these cases, they cannot consume enough forage to meet their daily digestible energy requirements. Additional calories are therefore, required and can be provided through a range of different feeds. Fibre-based feeds, such as many of the Chestnut range, or the addition of beet pulp to the ration, are a good starting point.
Beet Pulp contains high levels of soluble fibre, including pectins, which are highly fermentable - thus, it is termed, a ‘highly digestible fibre’ or even, a ‘superfibre’ - as the dry matter digestibility is approximately 80%. (Hyslop, et al., 1998) It is also higher in digestible energy than traditional fibre feeds, such as hay. In fact, the digestible energy levels in unmolassed beet pulp are similar to a medium-energy concentrate feed, yet the starch levels are much lower.
Older horses, particularly those with poor teeth, can struggle in the winter and lose condition dramatically. Chestnut unmolassed sugar beet flakes or Chestnut fibre nuts soaked into a mash, are a good addition or alternative to forage, when chewing becomes difficult.
However, it is important to remember that it is natural for equines to lose some weight in the winter months and fundamentally, owners should not get worried about a small amount of controlled, weight loss. Indeed, winter is the easiest time to manage horses and ponies that are overweight or obese, and owners should be using winter to their advantage to support healthy weight loss.
Overall, a winter-feeding programme should be based on pasture availability and good-quality forage, supplemented with appropriate sources of digestible energy, protein, vitamins, and minerals. A high fibre diet should meet the increased heat demands for an equine during winter. If you want to find out, which Chestnut Feed is most suitable for you horse(s), all you need to do is complete our nutrition request form.
Water Intake
As crucial as forage consumption is during the winter months, water intake is equally important. Horses lose water from their body through faeces, urine, sweat and even through exhaling air, as dry cold air increases water loss from the respiratory tract and lungs. On top of this, forage consumption in winter increases resulting in extra water being required for fibre metabolisation in the hindgut.
The accepted water requirement for horses is around 60ml/kg/day (Freeman, 2021). Thus, an average 500 kg horse requires approximately 30L of water per day as a minimum requirement. In addition, summer grass has moisture levels of approximately 60-80%, contributing to the horse’s water intake. In contrast, in winter, hay (and concentrate feeds) are fed more abundantly and these contain less than 15% moisture and so, do not contribute as highly to the horse’s daily water intake (Cymbaluk, 2013). Water is necessary for maintaining moisture levels in the horse’s gastrointestinal system therefore decreased water consumption causes ingesta to dry up, increasing the risk of impaction colic or intestinal blockages. (Bihonegn, 2018)
Kristula et al. (1994) performed a study consisting of two trials to compare ad lib consumption of ambient near-freezing water (ranging from 0℃ to 1℃) and warm water (46℃ to 49℃ when provided) to 14 ponies. The study concluded that on average, 40% of the ponies drank more warm water compared to ambient, near-freezing water. Based on this study, providing warm water for horses may encourage them to drink and help maintain hydration levels. Another factor to consider, is that low temperatures encourage water to freeze, therefore through correct management water troughs / buckets should be checked at least twice a day to break and remove any ice, if the water supply has frozen. Supplying warm water may minimise this risk, although for many owners this may not be practical.
A Balanced winter ration
A balanced winter ration will provide an horse with suitable amounts of digestible energy (DE), protein, fibre and vitamins and minerals, together with adequate water levels. Fibre-based feeds should always form the basis of any ration, and are especially important in the winter for ensuring a healthy hindgut environment, thermoregulation and the correct nutrient levels.
Try to keep a horse’s ration simple. Most horses (even those in high levels of competition) will do well on an ad-lib forage diet, plus additional concentrate feeds containing chaff, soluble fibre-based feeds, possibly some additional high-calorie oil-based feeds, such as micronised linseed meal; and finally, the correct level of vitamins and minerals. The Chestnut Lifestyle range provides a selection of fibre based, fully balanced complete feeds specifically formulated to meet the requirements of a wide range of horses and to help horse owners keep feeding simple. If you have any questions or want to find out more about the range, just get in touch.
REFERENCES
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