Feeding for Weight Gain in Thoroughbreds

Feeding for Weight Gain with Nicole Groyer, Nutritionist at Connolly’s Red Mills .

Feeding for weight gain
Many excitable horses are poor doers and they tend to burn off more energy than laid back individuals. Weight loss will negatively impact performance and without intervention, a horse’s body condition score will continue to fall. The first step to addressing unwanted weight loss is to determine possible causes such as a parasitic burden, poor dental condition or equine gastric ulcer syndrome. Alongside a feeding regime, it’s also vital to ensure that your horse is given plenty of forage, ideally ad lib, to help maintain a healthy digestive system. Regularly weighing and assessing your horse’s body condition score (BCS) will help you to spot the signs of weight loss early. Body condition scoring assesses accumulated body fat, both visually and by touch in six areas and assigns a score to describe its body condition. Loss of body fat should not be confused with loss of muscle mass. Your horse may also look like it is losing condition if muscle mass reduces, for example, due to injury, lack of adequate exercise or if the diet does not provide sufficient levels of nutrients such as high-quality protein and vitamins to maintain and support muscles. Knowing if the horse is losing body fat and or muscle mass can help to determine the cause and most suitable method to address the issues. Check out the Connolly’s RED MILLS Instagram post here for information on how to carry out a BCS on your horse.

Causes of weight loss

Consider the main causes of weight loss and what can be done to rectify the problem. Simply put, weight loss occurs due to a negative energy balance. A horse will maintain condition when the calorie intake matches the horse’s energy output. If your horse is using up more energy than he is taking in, the balance will shift, and the horse will start to lose weight. To identify the cause of weight loss consider the horse’s lifestage, environment, climate, health status, and diet.

Older horses often have trouble holding condition. They may have difficulty chewing forage due to dental issues, and old age may compromise the efficiency of digestion. An older horse with chewing difficulties may require switching to a feed which can be fed soaked such as hay cubes, beet pulp, Comfort Mash or a hard feed which could be fed soaked like Horse Care Ultra in order to support feed intake and digestion. If your older horse does need a ‘forage replacer’ we recommend you speak to our expert team, who will be able to recommend a suitable diet for your individual horse’s needs. If an older horse is losing weight due to compromised digestive efficiency a more energy- and nutrient-dense diet providing increased levels of high-quality protein, calories and vitamins and minerals may help the horse regain weight.

The environment the horse lives in will also impact their body condition. Horses use calories to keep themselves warm and cool themselves down, so very harsh winters or very hot summers can exacerbate weight loss. Herd pecking order will also influence feed intake. Horses low down the pecking order are often chased away from feed sources leading to a decreased overall intake of feed. Or soundness issues could make it more difficult for the horse to access feed in a group situation. Another factor to consider is climate as this will influence pasture quality and intake. Hot summers and drought will result in less grass being available and decreased pasture quality. During winter pasture quality will similarly decline. It is important to always keep an eye on pasture and hay/ haylage quality, so that you can adjust the diet accordingly whenever necessary to ensure adequate calorie intake.

Underlying health issues leading to weight loss
Some horses may be underweight due to health problems which may require veterinary attention. Parasites, dental issues, infectious disease, ulcers, and chronic pain must be ruled out as the cause of unwanted weight loss before making any changes to the diet. Some underlying medical conditions such as ulcers will require the support of a special dietary regime to help the horse gain weight and condition. Dietary management of a horse suffering from ulcers should include ad-lib access to hay/ haylage or pasture wherever possible, providing an energy-dense and low-starch diet and feeding smaller concentrate meals. The concentrate feed should provide calories from non-cereal grain sources such as highly digestible fibres, for example, beet pulp. At Connolly’s RED MILLS our Horse Care range includes a variety of low-starch feeds relying on alternative energy sources.

What do I need to feed for weight gain?
Like humans, horses gain weight by consuming more calories than they use. Therefore, when selecting a feed for weight gain one of the most important factors to consider is its energy (calorie) content, which is measured as mega joules of digestible energy per kilogram of feed (MJ/ kg DE) – the higher the number, the more calories it contains. Typically, feeds marketed at promoting condition, such as Conditioning Mix or Horse Care Ultra Cubes, contain around 12-13.5 MJ/kg DE. It is also important to consider the recommended feeding rate. A low intake balancer is obviously going to provide less calories, because you feed relatively small amounts, than a feed designed to be fed at a higher rate. The only exception to this are products that have been specifically formulated to be very high in calorie, even when fed in small amounts. For example, Define & Shine is a calorie dense (15.5MJ/kg) pellet that can be added to an existing diet to provide an extra source of calories, whilst keeping meal sizes small.

Which ingredients are most effective for weight gain?
Almost all the ingredients in a bag of feed will contribute to the overall calorie content including; cereals (e.g. oats, barley, maize), fibre (e.g. sugar beet, soya hulls, wheatfeed) and oil (e.g. linseed oil, soya oil). Of these ingredients, the most calorific ingredient is oil, which provides approximately 2.5 more calories than cereals. Horse Care Ultra Cubes are formulated to be high in oil. When extra, nonheating calories are needed Define & Shine can be added to the ration. Define & Shine contains 18% oil and includes beneficial omega-3 fats. It is important to consider the quality of the ingredients and the processing techniques used to make the feed to ensure it is as digestible as possible for your horse. All of Connolly’s RED MILLS feed are produced using only the best natural ingredients and our manufacturing processes of steam cooking, extrusion and double pelleting ensure maximum digestibility and that all nutrients are readily available to the horse during digestion.

My horse is excitable, what feed ingredients should I avoid?
Cereals (for example oats and barley) provide what is commonly referred to as ‘fast release energy’, as they are digested and absorbed into the blood stream relatively quickly. High cereal feeds may exacerbate ‘fizzy’ behaviour in horses that naturally have an excitable temperament, although the reasons for this are not fully understood. On the other hand, fibre and oil are broken down and absorbed relatively slowly. Consequently, they are known as ‘slow release’ energy sources. Nervous, excitable, or stressy horses can often ‘waste energy’ and as a result may lose weight. To help these horses maintain optimal weight and promote an even temperament a feed from our Horse Care Range that provides energy from fibre ingredient (e.g. sugar beet, soya bean hulls, alfalfa meal) and oil will be more suitable than a cereal-based ration.

How quickly will my horse put weight on?
Weight gain will not happen overnight, it takes time and will depend on how much weight the horse needs to gain. The National Requirements for Horses suggested that it takes 16-20 kg of weight gain
to change a horse’s body condition score by 1 unit (based on a 500 kg horse; 1-9 scale). Consequently, it will usually take at least 3-4 weeks before horse owners can see noticeable weight gain. It should be noted that severely emaciated horses will require specific dietary and veterinary support as they can suffer from an often fatal condition known as re-feeding syndrome.

My horse’s weight is ok but he is lacking muscle, what can I feed him to help him develop topline? 
Topline consists largely of muscle, which is predominately made from protein. Protein is made up of non-essential and essential amino acids. The latter cannot be made in the body and must be provided in the diet. Good quality protein is rich in these essential amino acids and plays an important role in building and maintaining muscle tone, as well as repairing exercise-induced muscle damage. When selecting a feed to help support topline development it’s important to look at both the crude protein level and the list of ingredients, both of which will be listed on the bag/label. This will help you ascertain the overall protein content of the feed and, more importantly, the quality of this protein. Good quality protein sources (e.g. Hi-Pro Soya or Full-Fat Soya) should appear high up on the list of ingredients. For horses needing additional support to maintain condition and develop topline Define & Shine is ideal. This high calorie and protein pellet aids weight gain and supports muscle development. It is rich in branch chain amino acids (BCAAs) which, alongside exercise, help your horse’s topline by limiting muscle soreness and preserving muscle mass. For good-doers needing topline a conditioning feed is likely to be too calorific and in these situations a feed balancer such as PerformaCare Balancer is an excellent choice. This will provide a concentrated source of quality protein (30% crude protein) and essential vitamins and minerals, whilst limiting calorie intake. It’s important to remember that it can take a few months to build topline on a weak horse and feed is only one piece of the puzzle. A suitable exercise regime that targets the correct muscle groups is also essential


Thanks to Nicole Groyer at Connolly’s RED MILLS for sharing her invaluable knowledge.


Check out the other articles done by Nicole: Reduced Workloads for ThoroughbredsFeeding for a Balanced TempermentFeeding the off the track thoroughbred.


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