Owners of horses who seem to gain weight on fresh air may find knowing how to feed a fat horse who lives out year-round a real challenge as they try to balance providing sufficient nutrition to cover their essential requirements for good health, without seeing their waistline expand.
Obesity in horses is a real risk to health, with weight-related problems including increased stress placed on limbs and joints, a higher risk of heart disease, circulation problems, digestive disorders and decreased resistance to disease, as well as increasing the likelihood of laminitis occuring.
So if you own a horse or pony who is a good doer, what steps can you take to ensure they achieve a healthy weight and then maintain it? The good news is that going into winter is a great opportunity for these horses to lose weight as nature intended.
Assuming there are no underlying health conditions leading the horse to become overweight, such as equine metabolic syndrome, the most common cause is that the horse is taking on more energy in the form of calories than they are using in exercise, which results in the excess energy being stored as fat.
One of the first things to look at when considering how to feed a fat horse is the quality of your horse’s grazing. This is going to be the primary food source for any horse living out 24/7. If you have a horse that tends to carry too much weight, then this is likely to be the root of the problem, particularly if the horse is in a large field of good quality grass.
While the nutritional value of grass will reduce during the winter months, a field of well-fertilised grazing, such as that produced by farmers for cattle, will still contain a high level of calories for horses to consume.
So how can you reduce the calories from the grass your horse has access to feeding a fat horse ? Equine nutritionist Christine Smy suggests:
- Consider the size of your horse’s field – is there a smaller field available?
- Could you use electric fencing to strip graze or set up a track system?
- Is it possible to use sheep to eat down the grass, so there is less of it for your good doer to munch on?
- If none of the above are possible, you may need to use a grazing muzzle to restrict the amount of grass your horse can eat
If you run short of grass in the winter – or there is snow on the ground – then additional forage will need to be supplied to maintain the horse’s gut health, but try to feed hay that has been a late cut if possible, as this typically has a lower nutritional value, or even better, have your hay tested so you know its nutritional value.
Another option is to mix hay with quality oat straw up to a 50:50 ratio to reduce the calories while maintaining plenty of roughage passing through the horse’s gut. Research undertaken by Redwings and the University of Edinburgh in 2020 has found this can be an effective way to help fat horses lose weight. Ruth Morgan, co-author of the study and researcher at the University of Edinburgh, does recommend that anyone feeding a mix of hay and oat straw ensures that their horse’s teeth are in good condition before introducing straw as it does take more chewing — this will also reduce any risk of impaction colic (none of the horses in the 2020 study displayed any signs of colic). Owners should also keep an eye on the horse’s droppings to ensure their digestive system is managing to move the less digestible forage through efficiently.
It’s important that horses living out full-time are getting all the key nutrients needed to maintain good health. Having your hay analysed to check its feed value will help you to ensure your horse is receiving a well-balanced diet. In terms of bucket feed, a feed balancer designed for good-doers combined with a low-calorie chaff will provide all your horse needs with minimal calories.
What feeding experts recommend
For Dr Katie Williams Ph.D. MSc (Dist) RNutr, senior nutritionist at Dengie, encouraging trickle feeding as much as possible is key for overweight horses with conditions such as equine metabolic syndrome (EMS) and Pituitary Pars Intermedia Dysfunction (PPID). A consequence of these issues is insulin dysregulation, which means the horse’s hormonal response to eating is disrupted.
“A key function of chopped fibre in the bucket feed is to slow the rate of intake,” she explains. “A study by Ellis et al. (2005) found the addition of chopped straw, at an inclusion rate of 20%, to a ration containing pellets and other chopped fibres resulted in significantly longer eating periods as well as an increased number of chews.
“Other studies have shown that feeding straw as part of the forage ration can slow the rate of intake to such an extent that no discernible insulinemic response results (Jansson et al. 2021), which makes sense when we think about the basic principle of the horse being a trickle feeder.”
While chopped straw is a useful addition to the good doer’s bucket, Katie recommends it is fed as part of a balanced diet as straw contains much lower levels of natural vitamins and minerals than grass-based forages.
“Meadow Lite with Herbs is Dengie’s ultra-low calorie feed, providing just 5MJ/kg of digestible energy,” she says. “It’s also naturally low in sugar (3%) and starch (0.5%) – levels way lower than you would find even in timothy hay. It’s ideal for mixing with a supplement or balancer to ensure the diet is balanced”
She adds: “For those worried about ulcers then Dengie Ulser Lite is a low calorie (8MJ/kg), sugar (6.5%) and starch (2%) fibre feed with added herbs, yeast and prebiotics to promote digestive health. It contains a blend of soft chopped grasses with high-quality oat straw for maximum fibre content while still keeping the calories low. Alfalfa pellets are included for natural buffering due to their high levels of bioavailable calcium.”
To reduce a good doer’s overall calorie intake, Top Spec nutrition director Nicola Tyler BSc (Hons) RNutr recommends looking at the whole diet.
“If you consider that an average 500kg horse would eat between 10 and 15 kilos of forage a day, then what type of chaff you feed at a rate of 125–600 grams per day makes very minimal difference,” she explains.
“You make a far bigger impact with the main forage, and controlling that as much as you can.”
For the good doer, Nicola recommends late-cut meadow hay. “It tends to be lower in sugar and protein, and higher in fibre,” she says.
“For horses who are competing but have got excellent forage and carry their weight well, we would recommend TopSpec Performance Lite feed balancer. For horses who are obese or whose forage intake is restricted due to a condition such as EMS, TopSpec AntiLam forage balancer is ideal. It’s very slightly lower calorie, but has a much higher level of micronutrient support, because it’s those micronutrients that are going to be massively missing in his diet due to such significant dietary restriction.”
Echoing the importance of key micronutrients in an overweight horse’s diet, Sarah Nelson BSc (Hons), product manager at Spillers, says: “Forage only diets often exceed the calorie requirements of good doers, but are likely to fall short of key nutrients including copper, zinc, selenium, vitamin E and lysine.
“Protein is made up of ‘building blocks’ called amino acids, some of which are described as ‘essential’ because they can’t be synthesised by the horse and must be provided in the diet. Lysine is considered the most important essential amino acid and may be deficient in weight loss diets,” she continues. “If a horse’s lysine requirement isn’t met, the body will begin to break down muscle tissue to try and meet demand.
“Spillers Lite & Lean balancer is specifically formulated to balance a calorie-restricted diet and is high in vitamin E and lysine.
“Feeding a balancer alongside a low-calorie short chopped fibre, such as Spillers Fibre Lite Molasses-Free, helps to bulk out the bucket and extend eating time without compromising the good doer’s waistline.”
Other considerations: how to feed a fat horse
If your horse is living out wearing a rug during the winter, it is important to regularly remove the rug to check their physical condition, as well as to allow their skin the chance to breathe and to check for any rubs or injuries that may have occurred. This is particularly important if you’re not riding regularly.
However, ask yourself if your horse really needs a rug? Many native types living out unclipped are able to cope with the worst of the British weather and are likely to be more comfortable without rugs if there is sufficient shelter — either natural or man-made — to allow them to escape from the wind. If you need your horse to lose weight then no rug will allow the horse to use its natural internal warming system to maintain its body temperature, which in turn will help burn the calories it would otherwise lay down as fat.
If your horse has a thick winter coat, it may be difficult to assess their condition by eye, so it’s recommended to get hands-on to assess their body condition score, combined with weekly use of a weight tape, to monitor weight loss or gain. Use the tape weekly at the same time of day and keep a note of the measurements. A gradual weight loss is, as it is in humans, more desirable than losing a lot of weight quickly.
Exercise is a key element of ensuring your horse loses weight. If you are unable to exercise your horse during the winter months, due to limited daylight or other restrictions, then consider the layout of your turnout to encourage the horse to move more. Track systems are becoming increasingly popular as they encouraging the horse to move naturally between areas where they can eat, drink and relax, which can aid weight loss.
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You may also be interested in:
How to calculate your horse’s body condition score – is he the right weight?
Track living: the alternative horsey set-up
Grazing muzzles – what are your options?
Feed balancers: what’s on the market?
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