Is my horse overweight?
Determining whether your horse is overweight isn’t always easy. You see them every day so it can be difficult to spot the pounds gradually piling on, plus it is impossible to tell by eye alone how much fat your horse is carrying. The most convenient way to weigh your horse is to use a weigh-tape, ideally every fortnight. Although this might not be accurate in terms of your horse’s exact weight, it will help you to monitor if they are gaining or losing weight. In addition, body condition scoring (BCS) your horse regularly will help you to keep an eye on the amount of body fat they are carrying.
In a recent study where horse owners were asked to estimate their horse’s BCS using a scale of 1-5, findings showed that just under half the owners scored their horse at least one score lower than when the horse was assessed by an independent researcher. One of the reasons why horse owners commonly underestimate their horse’s BCS is that often fat is confused for muscle. With practise it is possible to distinguish the feel of these two very different tissues and BCS our horses according to their fat cover, and not their muscle or topline.
When BCS your horse pay special attention to any regional fat accumulation such as cresty necks. Ponies especially, are particularly prone to these regional fatty deposits. Fat accumulations are a characteristic often associated with an increased risk of metabolic laminitis. As a result scientists have developed a cresty neck scoring (CNS) system. The CNS system is on a scale of 0 to 5 where zero equals no visual appearance of a crest and five equals an enormous, permanently drooping crest. Whilst not all horses prone to laminitis will have a cresty neck research suggests that horses and ponies with a history of laminitis are more likely to have a CNS score of 3 or greater.
What are the health risks associated with equine obesity?
The link between obesity and/or regional fat deposits and laminitis remains contentious. However, there is increasing evidence to suggest that adipose tissue (body fat) is more than merely a calorie storage organ for fat. It’s an active tissue that can impair the body’s ability to regulate cell signalling proteins secreted by fat cells (e.g. adiponectin) and hormones (e.g. insulin). This is important as it is believed that insulin resistance (IR) may be the cause of many cases of pasture-associated laminitis. In healthy horses insulin is responsible for the uptake of glucose (sugar) into the cell, but in horses suffering from IR the cells become resistant to the glucose uptake action of insulin. Initially, higher levels of insulin (hyperinsulinemia) are needed to keep blood glucose concentrations within normal limits. However, in some cases resting insulin levels are elevated and even exceptionally high levels of insulin are ineffective at controlling blood glucose levels, this is called insulin dysregulation or dysinsulinemia.
Whilst Whilst the role of obesity and insulin dysregulation in the development of laminitis are still not fully understood there appears to be a link between excessive body fat, hyperinsulinemia and some cases of laminitis. This has led to the term ‘Equine Metabolic Syndrome’ (EMS) being used to describe horses and ponies that suffer from IR, are obese and/or have regional adiposity and have a history of, or are currently suffering from, laminitis. It is however important to bear in mind that not all obese horses suffer from insulin dysregulation and likewise not all horses suffering from insulin dysregulation are overweight. Consequently, many researchers are now questioning the usefulness of the term EMS.
In addition to increasing the risk of insulin dysregulation, obesity also contributes to other problems including joint issues, poor performance, reduced fertility and an increased risk of lipomas, which are a common cause of colic particularly in older horses and ponies.
How to feed the good-doer
When it comes to keeping your horse at a healthy weight and BCS, diet and appropriate exercise play very important roles.
Even horses prone to being overweight need plenty of forage. Total daily forage intake (including grazing), should not be restricted to less than 1.5% bodyweight, unless under veterinary supervision. Restricting below this level may increase the risk of problems such as colic, gastric ulcers and oral stereotypies (e.g. crib-biting). Research has also found that more than a few hours without forage may actually exacerbate IR as the body goes into ‘starvation’ mode. Acute starvation can also result in hyperlipemia, where the body releases large quantities of stored fats into the bloodstream. This cause the liver to work excessively and could be an extremely serious, potentially fatal, condition.
Whatever type of forage you are feeding it’s important that you try to avoid your horse spending long periods of time (greater than 4hrs) without forage. There are several excellent strategies you can implement to make preserved forage last as long as possible including; dividing the preserved forage into several small servings and/ or feeding it in multiple, double netted, small-holed haylage nets.
Haylage: Haylage is typically not recommended for horses or ponies that are prone to weight gain as it is usually more digestible and nutritious compared to hay or straw. Whilst there are high fibre, low sugar haylages that have been specifically produced with good-doers in mind, hay and/or straw is usually preferable.
Hay: A late-cut meadow hay is ideal for good-doers and, if necessary, it can be soaked in plenty of tepid water to further reduce its sugar and calorie content. Generally it is recommend hay is soaked for 6-8hrs in very warm climates, such as in the Middle East.
Straw: Replacing a proportion of the normal forage (up to 0.28kg per 100kg bodyweight) with fresh oat or barley straw can be helpful when trying to achieve weight loss. Straw must be introduced gradually and should never be fed to horses with dental issues as this can increase the risk of impaction colic. Straw is not recommended as the sole forage source for horses as a recent study has found that this can significantly increases the risk of gastric ulcers. The exact amount of preserved forage a horse needs is difficult to determine. As a rough guide if your horse is never turned out, or is turned out only for few hours, then the entire forage portion of the diet should be provided as preserved forage. However, for horses that spend 50% of their time at grass, or that are permanently out on a semi-starvation paddock, this can be reduced by half.
Limiting access, especially to lush grazing, is important to reduce the risk of obesity and laminitis. However, daily turn out on a sand paddock or arena with access to a suitable preserved forage, remains beneficial as this allows the horse to exercise freely.
It’s a common misconception that the hard-feed is the cause of obesity, in actual fact the majority of overweight horses receive very little in the way of hard-feed. Recent research has provided increasing evidence that improved forage and lack of exercise, not the hard-feed, are the two most common contributing factors in equine obesity. That said, the trouble with most commercially available feeds is that when they are fed at the recommended rate they often provide the good-doer with unnecessary calories, whilst feeding them at lower rates can mean that your horse does not receive optimal levels of essential vitamins and minerals. Feeding a balancer or a good supplement providing vitamins, minerals and amino acids presents a good solution.
Balancers are low intake, nutrient dense feeds packed full of all the essential micronutrients needed to balance the forage portion of the diet. They are specifically formulated to be fed in very small quantities (e.g. think about a cup, not scoop, per day) providing a calorie controlled ration for good-doers. Ideally, the balancer contains good levels of quality amino acids to support lean body tissue development. The ideal balancer is also low in starch and sugar, and low in cereals or even cereal-grain free, meaning that it is ideal for horses and ponies prone to laminitis, IR and EMS. Some balancers also contain additional ingredients such as prebiotics to help maintain a healthy digestive system.
Once your horse has lost any the excess weight and/ or their workload has increased, you may find that they need more energy. In these situations some people find that their horses respond well to being fed a small amount of a higher energy mix in addition to their balancer. The most suitable mix or cube will depend on a number of factors including the work your horse(s) is doing and whether they suffer from any clinical concerns. It is recommended that you contact the Connolly’s RED MILLS Nutrition Team if you wish to discuss your horse’s individual needs.
Fat acts as an insulator that raises the body’s core temperature as a result overweight horses may not regulate their body temperature efficiently. This can mean that during exercise an overweight horse will sweat more than normal. If the water and salts lost in sweat are not replaced, horses may become dehydrated which can lead to poor performance, lack of stamina and even muscle dysfunction. To keep your horse well hydrated you should always ensure that they have a plentiful supply of fresh, clean water. If your horse is a good-doer on very little hard feed, additional salt may be required in the diet. This can be provided as a salt-lick or by adding some salt to their daily feed. Plus, if your horse has sweated heavily, we recommend feeding a specific equine electrolyte supplement (e.g. Foran Equi-Lyte G) for at least 2 days.
The importance of exercise
Exercise is another important factor to consider when trying to keep your horse’s weight in check. Provided your horse is not currently suffering from laminitis try to exercise them for at least 30 min daily. Initially an overweight or unfit horse may find exercise tiring, but as their fitness gradually increases and/ or any excess weight begins to drop off their energy levels will improve. Remember that low–intensity exercise (e.g. walk and trot) is more effective weight loss for weight loss than short bursts of high intensity work, plus it may also help to improve insulin sensitivity.
Feeding the good-doer can be challenging and requires constant attention. You will need to carefully consider the quality and quantity of forage and hard-feed being offered along with your horse’s body weight and BCS. If your horse is overweight it may take several months for him to slim down and you should not become discouraged if visible changes are not readily obvious. Remember, the excess weight and condition did not accumulate overnight, so it will not disappear overnight. Time, patience and consistency are key!
If you would like to discuss your individual horse’s feed and management in more detail the Connolly’s RED MILLS Nutrition Team are on-hand to offer expert, practical advice.