• Briony Witherow BSc MSc RNutr. PGCERT FHEA

Feeding horses in winter

Independent equine nutritionist Briony Witherow, discusses how feed and management changes need to be monitored carefully


As we move into the winter months, it is worth considering feed and management changes and how these might impact our horses. In many cases, careful consideration and monitoring can help us to stay ahead of the curve and in doing so, avoid some commonly encountered problems.



Fundamental changes

Probably the most obvious changes for our horses at this time are in routine, workload and subsequently diet. The most common scenarios including; reduced turnout (and therefore movement); a change in workload (discipline dependent); and increases in concentrate feed and/or hay or haylage. The latter is often necessary as grass growth slows and ceases, and those that thrive on ‘Dr Green’ can often find this challenging, fundamentally due to grass typically being more digestible and higher in nutrients than the conserved equivalents.


For the digestive system, this represents a couple of key challenges – firstly, the change in moisture content of the diet, often moving from higher moisture (grass) to lower moisture (hay/haylage). Over the colder months, this is often coupled with reduced water intake, horses tending to dislike very cold water. Secondly, the decrease in movement through increased stabling and reduced turnout resulting in reduced gut movement. These factors combined may result in an increased risk for gut related problems such as impaction colic (the incidence of which is seen to rise over the winter months).


Several studies have identified reduced water intake and subsequent dehydration as a key risk factor for colic¹ ². More specifically water deprivation is thought to be associated with increased risk of impaction colic through the dehydration of food in the gut, an change in gut movement or both³ ⁴ ⁵ ⁶ ⁷.

Reduced water intake is also thought to be a risk factor for gastric ulcers and urinary tract infections, making maintaining water intake during the winter months a key focus area⁸ ⁹ ¹⁰.


Managing potential health risks

Maximise water and fibre intake

The relationship between fibre and water is often overlooked. Fibre acts as a reservoir for water and electrolytes in the gastrointestinal tract. In fact, fluid stored by the gastrointestinal tract can account for 9-21% of live bodyweight ¹⁵ ¹⁶ ¹⁷ ¹⁸. The choice of winter forage can assist in optimising moisture intake. For example, haylage with a moisture content of between 32-45% can supply approximately 25% of the water needs of sedentary and worked horses¹⁹. In addition to this, opting for soaked fibre additions such as Fibre Beet or Speedi-Beet in place of dry chaffs, can help to further boost moisture levels while also increasing fibre intake. Some of these soaked fibre sources can be used as partial or full forage replacement and therefore, can be useful for poor doers, picky fibre feeders or those stabled for long periods, to provide fibre enrichment and encourage intake and foraging behaviours.


Providing clean fresh water at all times is essential so, be sure to clean troughs and buckets frequently. In addition, learning your horse’s ‘normal’ water intake range is vital. Just like knowing your horse’s normal temperature or respiration rate, water intake should be recorded as part of your horse’s normal health parameters. Once settled into your winter routine, monitor your horse’s water intake over a normal week and take an average – remember to revise this whenever the horse’s routine, workload or feed changes (as this may result in a change in water intake).


When monitoring water intake, it can be easier to use buckets instead of automatic waterers. Get to know what size your buckets are in litres, which should provide a rough idea on intake. As a guide, a horse at rest would typically consume around 5 litres per 100kg bodyweight (25 litres for a 500kg horse), however the moisture content of the diet and other management and workload factors will impact this ¹¹.


Another important factor which may help to encourage appropriate water intake is ensuring your horse is receiving adequate levels of sodium. Even horses at rest or in light work are likely to require added salt in addition to their normal diet, even if they are receiving the recommended amount of a hard feed daily. For those at maintenance or light work on a diet high in forage, the provision of 0.02 x bodyweight of sodium which is 10g for a 500kg horse should meet minimum requirements. One way to adhere to this is by supplementing the diet with salt. Table salt (sodium chloride) is around 40% sodium. Feeding 30g (a heaped tablespoon) of table salt per day will provide 12g of sodium which is sufficient to meet the maintenance requirements of a 500kg horse. Requirements increase with workload and associated fluid losses and therefore for horses in moderate work provision should be increased (typically 2-4 tablespoons of table salt per day). Alternatively, salt blocks can be provided, however, this relies on the horse consuming adequate and consistent quantities which need to be monitored¹² ¹³.


In cold weather, warming up bucket/trough water by adding hot water can encourage greater intake (and potentially prevent/slow freezing). Studies have shown horses to have a preference to warm water between 20-35° in comparison to near freezing water¹⁴.


Maximise movement

Physical movement is an essential part of helping food pass through the horse’s digestive system. As such, periods of restricted movement such as box rest, fewer turnout opportunities or, perhaps less exercise can, along with other factors, culminate in higher risk of digestive issues over the winter months. Finding ways to facilitate movement, either through regular structured exercise and/or turnout on a bark paddock, arena, or other safe space is key. You can also help to encourage movement within a stable or barn by getting creative with resource placement, for example tying up nets in different corners or, using a hayball for part of the forage ration, this also helps to act as additional enrichment for those stabled for longer periods.


When looking to enrich the stable environment, optimising feed management and getting a little bit creative is key, see some top tips below:

  • Ensure your horse is receiving enough forage. All horses require a minimum of 1.5% of their bodyweight in dry matter per day.

  • Ensure that you have selected the most appropriate forage for your horse’s needs. This may be slightly different if your horse is stabled more than they might be normally. Selecting the most appropriate forage may mean that the ration does not require restriction which will help to occupy more time while stabled.

  • Try to ensure that the forage ration is divided reasonably equally throughout the day/night. Typical yard visits (8am and 5pm for example) sometimes mean that simply dividing the total forage ration in half, results in more forage being available during the day per hour than overnight.

  • Try to estimate how long the forage ration may be lasting. Time how long it takes your horse to eat a set amount of his forage ration (1 or 2kg) over a few days. Multiply this up so that it gives you an estimate of ‘eating time’ for the whole ration. With this information you can gauge whether a slow feeder or some management to extend eating time may be beneficial.

  • For those who are missing Dr Green and less than enthusiastic about the alternatives, try creating a stable-based fibre buffet. A selection of forages can help to encourage natural foraging behaviours and in doing so may help to increase the amount your horse eats.


Longer time stabled, less movement and increased intake of dry matter can lead to impaction colic

Facilitate gradual changes

Planning ahead is key and can help you to achieve a smooth transition between the seasons. Where possible, only make one change at a time. In situations where the hard feed needs changing as well as the forage, change the forage first and then, once settled in your new routine, you can think about changing the hard feed. This is not only a sensible choice for the digestive system but also avoids multiple ration changes – a common mistake during this period where the hard feed and forage is changed simultaneously is that you may end up overfeeding energy/calories.


Where possible, forage changes should be made over 3 to 4 weeks and changes in hard feed over at least 10-14 days or longer for those with a history of colic or a sensitive digestive system. While this may seem impractical, taking some care at this stage can help to avoid problems later on. Where a gradual decrease in grazing time is not possible, practices such as offering hay/haylage in the field or, bringing the horse in for a few hours a day for hay/haylage to help increase fibre and dry matter intake slowly, can work well.

During this transitional period, monitor your horse’s droppings and use this as a guide as to how well the digestive system is coping – if they change suddenly at any point this may be an indication that the change in diet or management is too quick. For those who find a change in routine/diet difficult to manage, consider using a digestive supplement to support the system through periods of change.

A change in season always presents some challenges, however recognising the fundamental challenges faced and considering these in our management can, in many cases help to avoid health issues.


References

  1. Kaneene, J.B., Miller, R.A., Ross, W.A., Gallagher, K., Marteniuk, J., and Rook, J. (1997) Risk factors for colic in the Michigan (USA) equine population, Preventative Veterinary Medicine, 30: 23-36

  2. Reeves, M.J., Salman, M.D., Smith, G., (1996) Risk factors for equine acute abdominal disease (colic): Results from a multi-centre case control study. Preventative Veterinary Medicine 26: 285–301.

  3. Williams, S., Horner, J., Orton, E., Green, M., McMullen, S., Mobasheri, A., & Freeman, S. L. (2015) Water intake, faecal output and intestinal motility in horses moved from pasture to a stabled management regime with controlled exercise. Equine Veterinary Journal, 47(1): 96–100.

  4. Cox, R., Burden, F., Gosden, L., Proudman, C., Trawford, A., and Pinchbeck, G. (2009) Case control study to investigate risk factors for impaction colic in donkeys in the UK, Preventive Veterinary Medicine, 92: 179-187

  5. White, N.A. (1997) Risk factors associated with colic. In: Robinson, N.E. (Ed.), Current Therapy in Equine Medicine, fourth ed. W.B. Saunders Co, Philadelphia, pp. 174–179.

  6. Pugh, D.G., Thompson, J.T. (1992) Impaction colics attributed to decreased water intake and feeding coastal Bermuda grass hay in a boarding stable. Equine Practice, 14 9–12.

  7. Hillyer, M.H., Taylor, F.G., Proudman, C.J., Edwards, G.B., Smoth, J.E., French, N.P., (2002) Case control study to identify risk factors for simple colonic obstruction and distension colic in horses. Equine Veterinary Journal, 34: 455-463

  8. Luthersson, N., Nielsen, K.H., Harris, P., Parkin, T.D. (2009) Risk factors associated with equine gastric ulceration syndrome (EGUS) in 201 horses in Denmark, Equine Veterinary Journal, 41 (7): 625-630

  9. Dusterdieck, K.F. (2007) Equine Urolithiasis. Veterinary Clinics of North America Equine Practice, 23: 613-629

  10. Frye, M.A., (2006) Pathophysiology, diagnosis and management of urinary tract infection in horses, Veterinary Clinics of North America: Equine Practice, 22: 497-517

  11. Groenendyk, S., English, P.B., and Abetz, I. (1988) External balance of water and electrolytes in the horse. Equine Veterinary Journal, 20: 189-193

  12. Jansson, A. and Dahlborn, K. (1999) Effects of feeding frequency and voluntary salt intake on fluid and electrolyte regulation in athletic horses. Journal of Applied Physiology, 86, pp. 1610-1616.

  13. Jansson, A., Rytthammar, A. and Lindberg, J.E. (1996) Voluntary salt (NaCl) intake in Standardbred horses. Pferdeheikunde, 12, pp. 443-445.

  14. Kristula, M.A., and McDonnell, S.M. (1994) Drinking water temperature affects consumption of water during cold weather in ponies, Applied Animal Behaviour Science, 41:155-160

  15. Robb, J., Harper, R.B., Hintz, H.F., Reid, J.T., Lowe, J.E., Schryver, H.F., and Rhee, M.S.S. (1972) Chemical composition and energy value of the body, fatty acid composition of adipose tissue and liver and kidney size in the horse. Animal Production, 14, 25-34

  16. Coenen, M. and Meyer, H. (1987) Water and electrolyse content of the equine gastrointestinal tract in dependence of the ration type. Proceedings of the Equine Nutrition and Physiology Symposium 10, 531-536

  17. Gee, E.K., Fennessy, P.F., Morel, P.C., Grace, N.D., Firth, E.C., and Mogg, T.D. (2003) Chemical body composition of 20 Thoroughbred foals at 160 days of age and preliminary investigation of techniques used to predict body fatness. New Zealand Veterinary Journal, 51 (3): 125-131

  18. Sneddon, J.C., Boomker, E., Howard, C.V. (2006) Mucosal surface area and fermentation activity in the hind gut of hydrated and chronically dehydrated working donkeys. Journal of Animal Science, 84:119-124

  19. Muhonen, S. (2008) Metabolism and hindgut ecosystem in forage fed sedentary and athletic horses. PhD thesis, Swedish University of Agricultural Sciences, Uppsala, Sweden.


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