Feeding to achieve weight loss
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Horses have evolved to graze up to 22 hours per day and, in the wild can typically cover 20 miles per day in search of fresh grazing and water. This serves as a good reference point for what a healthy horse can accommodate under natural conditions and why, in domesticated conditions, management often leads to weight gain. This also highlights that exercise plays an essential role in any weight loss regime.
Is my horse fat?
First things first, we need to establish whether the horse is fat and, if so, how fat!
The difficulty with many methods such as weightapes, formulas and weighbridges is that they just provide you with a number. This number then needs to be put into context as, on its own, it tells us very little. Just like in humans, weight on a set of scales, for example, is not only reflective of body fat but also muscle (which, incidentally, weighs more than fat), hydration status, gut fill and amount of bone (density). As such, you can imagine how any slight change in reading could be misleading.
The best method to ascertain a horse’s fat distribution is body condition scoring (BCS), also known as fat-scoring, where the fat covering of the horse is palpated, visually assessed and given a score. The 0-9 system incorporates more areas for evaluation and more increments upon which to score. This system involves scoring 6 areas (neck, withers, back, tail-head, ribs and behind the shoulder) from which an average is taken to obtain the overall BCS.
With regards to what is considered a healthy BCS, this varies depending on the scale used, personal perception, health considerations and purpose of the horse. It is generally perceived that between 4 and 6 on a scale of 0-9 is ideal.
How did we get here?
Generally speaking, weight gain occurs where a horse’s nutritional intake is greater than the physical energy demand, however there are a number of factors which can intensify this process, like changes in food availability or activity levels and genetic influences. A lack of knowledge or appreciation of how the horse has evolved may also be to blame. Unlike its feral counterpart most domestic horses undergo minimal work yet are receiving a relative abundance of forage, provision of shelter and rugs resulting in increased calorie consumption and reduced calorie burning.
This is intensified by the animals’ naturally adaptive behaviour of building up stores of body fat in the summer as a buffer against the ‘inevitable’ shortage of winter feedstuffs.
As the majority of the horse’s diet should be comprised of forage, this is likely to be the main source of calories. Since the majority of leisure horses (in rest to light work) consume sufficient calories from their forage alone to maintain weight (in many cases concentrate feed just serving the purpose of balancing the forage), this is where the focus should start when considering weight loss.
A misjudgement of workload may also be a factor. Recommended amounts of concentrate feed are typically based on bodyweight and workload – as such, if the workload is overestimated, this can result in an oversupply of calories/energy.
The use of rugs, stables and winter feed all offset the natural winter weight loss which horses and ponies have evolved to do. Over a number of seasons this weight accumulation can cause a horse or pony to go from moderate fatness to obese.
How to ACHIEVE weight loss
Forage should still represent the majority of the good-doer’s diet but the difficulty with forage is that it is much trickier to assess its calorie content and how much is being consumed, particularly with grass. Forage analysis may reveal part of the picture but can be expensive and will only represent a snapshot in time and therefore may be misleading. One thing that you can do is opt for a later cut hay or haylage which tends to be coarser and stalkier, contains a larger percentage of indigestible fibre and therefore fewer calories.
It is rare to be able to feed ad lib forage to a good-doer and, as a general rule, for weight loss we would look at providing a total daily intake of the equivalent of 1.5% of ideal bodyweight of forage, on a dry matter basis. Reducing to this amount should be achieved gradually and, to further reduce the calorie content of your hay, soaking is the next option as this "washes" out water soluble carbohydrate (wsc) calories leaving the insoluble fibre for the horse to chew on.
Soak time should be increased gradually, to allow the horse to become accustomed to the taste (like reducing the sugar in your tea!), with a target of 8 hours when maximum wsc reduction can be achieved. Initially, soaked hay can be mixed with dry, to help get the horse used to it, while spraying soaked hay nets with cooled herbal tea can also tempt the fussy eater.
Care should be taken when soaking hay in hot weather; find a shady spot for the soaker to reduce the risk of mould and bacterial build up, and use clean fresh water each time. It's also a good idea to rinse the soaked net with fresh water and allow it to drain in the shade too.
When it comes to grazing, you have a number of options. As research shows that stabling for a period of time and then turning out is ineffective – the horse/pony adapting and increasing his intake accordingly - we have to look to other strategies to promote movement and increase chew time while reducing calorie intake.
Strip grazing
Offers a relatively easy way to control consumption of grass. A ‘forward fence’ and a ‘back fence’ provide controlled amounts of fresh grass whilst also allowing grazed pasture to recover. Overgrazing can expose plant crowns, containing higher levels of sugar and starch, as well as preventing effective regrowth. Moving the forward fence as a whole, having the water trough at the opposite end to fresh grass, an L or U shaped paddock, or natural obstacles will all encourage movement.
Grazing Muzzles
Can help to control bite size, and in doing so reduce intake by up to 80%, but must be used with care and be introduced slowly. Most manufacturers recommend grass is at least 2 inches long and that the muzzle is not worn more than 12 hours a day. Bare paddock turnout/stabling can be utilised in conjunction with suitable hay/haylage to reduce calorie intake. This is ideally combined with a grazing muzzle during the time spent at grass to prevent horses compensating for reduced time at pasture.
Extending chew time, and therefore the amount of time the horse is occupied, is key to effective and safe weight loss. Good-doers therefore need strategies to control the quantity of forage they eat AND prolong its consumption.
• Use small holed nets, or simply double net haylage nets.
• Use a number of haynets at different points around the stable
• Use different fibre types (hay /chaff /Beet) to encourage natural foraging behaviour
• Use feed balls to entertain while also ensuring a steady trickle of fibre
• Use compressed fibre blocks
Energy and Calories, one and the same – how to achieve one without the other
When looking at appropriate concentrate feeds there are two main factors to consider; calorie level and how much by weight is fed. The calorie level of a feed is described by the Digestible Energy (DE), which is the measure of the estimated energy/calorie content. When assessing calorie contribution, it is important that you are aware of both the calorie level AND the weight of the feed being provided.
For example:
2kg of High Fibre Cubes @ 8MJ/Kg
= 16MJ per day
0.45kg of Lo-Cal balancer @ 11MJ/Kg
= 4.95MJ per day
In order to ensure a balanced diet while encouraging weight loss, your horse must be fed the full recommended amount for bodyweight and workload. A product designed to be fed by the Stubbs scoop will not deliver a balanced diet when fed by the hand or mug full. Choosing a concentrated low calorie balancer, which is designed to be fed by the mug-full, is generally the best option to support a diet based on controlled amounts of forage, especially where this forage is being soaked, as this washes out essential nutrients as well as calories.
Balancers are designed to supply those nutrients already known to be lacking in modern forage and pasture and do this while supplying only negligible levels of calories. Alternatives include low calorie "fortified chaff", fully balanced chaff-based feeds but care must be taken to ensure these are fed at recommended levels to ensure the horse or pony is not missing out on essential nutrients. When feeding these high fibre feeds, the overall forage intake may need adjusting, to account for the additional fibre and calories supplied. If in doubt, contact our Nutrition Team!
