9 min read Last updated: January 2026 If your ex-race Thoroughbred turns fizzy after hard feed, youre not alone. This guide shows how to calm behaviour and add condition by building diets around adlib fibre, low starch and added oildelivering slow-release energyso you can feel a cooler brain within 24 weeks. Quick Summary Short on time? Here are the key takeaways. Area: Prioritise fibre & oil What To Do: Feed adlib hay/haylage and build the bucket with lowstarch, highfibre/oil feeds; add linseed or soya oil gradually. Keep mixes small and frequent. Why It Matters: Slowrelease energy avoids sugar/starch spikes that drive fizz. Common Mistake: Relying on cerealheavy or molassed feeds for calories. Area: Adlib forage What To Do: Provide continuous access to hay/haylage; if restricting, use smallhole or multiple nets and feed littleandoften. Why It Matters: Forage buffers stomach acid, keeps the gut moving and steadies behaviour. Common Mistake: Allowing long fasting periods, especially in winter. Area: Swap to superfibres What To Do: Remove barley, molassed mixes and sweet feeds; use highfibre, highoil cubes or soaked lowstarch options with unmolassed beet pulp/soybean hulls. Why It Matters: Maintains calories without postfeed fireworks. Common Mistake: Choosing starchy mixes instead of lowerstarch cubes for hot TBs. Area: Condition without fizz What To Do: Use highoil, lowstarch conditioning cubes or soaked feeds alongside adlib forage; add unmolassed beet pulp if more calories are needed. Why It Matters: Adds weight and work energy without winding the horse up. Common Mistake: Adding cereals for condition or pairing Soothe & Gain with barley/molasses. Area: Gut first, calmers What To Do: Fix forage access, cut starch and stabilise routines before adding a calmer; pick clearlabel products (e.g., magnesium, Ltryptophan). Why It Matters: Calmers only help once the base diet and management are correct. Common Mistake: Expecting a calmer to offset a cerealheavy ration. Area: Winter management What To Do: Lean on fibres central heating, keep turnout and work regular, feed small frequent meals, and rug appropriately for changeable weather. Why It Matters: Comfort and routine reduce stress and excitability when stabled more. Common Mistake: Using heating cereal mixes or poor rug fit/weight instead of fibre and management. Area: Safe feed changes What To Do: Transition over 710 days, swapping 25% every 23 days; keep TB meals under 2 kg, add oil slowly, soak as directed, ensure fresh water. Why It Matters: Protects the hindgut and prevents digestive and behaviour upsets. Common Mistake: Abrupt switches or oversized feeds. Area: Monitor & seek help What To Do: Log body condition, girth, behaviour, droppings and appetite weekly; call your vet for ulcer signs or sudden behaviour change. Why It Matters: Tracking shows progress early and flags issues before they escalate. Common Mistake: Ignoring girthiness, teethgrinding or intermittent colic. In This Guide Why fibre and oil calm excitable Thoroughbreds Build the diet around ad-lib forage Swap starch for superfibres and oil Conditioning ex-racers without the fizz Support the gut first, then consider calming supplements UK winter management to keep Thoroughbreds chilled How to transition feeds safely Monitoring progress and when to seek help If your ex-race Thoroughbred feels like a firecracker after hard feed, youre not imagining it. What you feed and how directly affects behaviour, especially in sharp, stressy types.The calmest TBs are built on ad-lib fibre, low starch and added oil not cereal-heavy mixes.Why fibre and oil calm excitable ThoroughbredsFibre and oil deliver slow-release energy without the sugar/starch spikes that drive fizz.Fibre is digested in the hindgut and provides steady energy thats rarely linked to excitability, unlike sugar and starch which act like rocket fuel. High-energy fibres (think unmolassed beet pulp and soybean hulls) and oils supply extra calories for work or weight gain without the behavioural blowback you often see with grains. Oil is especially efficient it provides roughly 2 times the calories of cereals, making it ideal for adding condition to hot TBs without winding them up.Choose super-fibre concentrate horse feeds rather than starchy grain-based concentrate feeds, as some horses become too excitable when eating moderate to high intakes of starch. Clare Macleod, MSc Nutritionist (Your Horse)In practice, this means shifting calories from cereals to fibre and oil. The result: a horse that holds weight and work better, with a cooler brain for schooling, hacking and competitions.Build the diet around ad-lib forageFor a hot TB, adlib hay or haylage is the foundation to buffer stomach acid and keep behaviour steady.Continuous access to forage keeps the gut moving, promotes saliva (a natural antacid), and reduces the gastric discomfort that can make horses anxious, girthy or sharp. If you must limit intake for weight reasons, use small-hole nets or multiple nets and feed little-and-often to avoid long fasting periods.UK winters add pressure: wet weather and reduced turnout raise the risk of stress and ulcers. The British Horse Society (BHS) emphasises fibre-first rations to mimic grazing and support welfare for stabled horses over winter. Fortunately, fibre also acts like central heating; hindgut fermentation helps keep horses warm, so you can lean on forage rather than heating cereal mixes during cold snaps.Turnout remains essential for mental wellbeing and natural energy release, even if its short, daily sessions between showers. When turnout is limited, plan ridden work and in-hand walks to break up stabled time. Good rugging supports comfort without resorting to high-starch feeds browse our proven winter options in winter turnout rugs and cosy stable rugs to keep your TB comfortable in changeable UK weather.Eliminating digestive discomfort needs to be a primary concern whenever you are feeding an excitable horse... Base your horses diet around ad-lib fibre, supported by a balanced diet low in sugar and starch, which is also whole cereal and molasses-free. Anna Franklin, Equine Nutrition Advisor, Blue Chip (Your Horse)Swap starch for superfibres and oilReplace molassed, cereal-rich mixes with lowstarch, highfibre/oil feeds to stop post-feed fireworks.Start by removing barley, molassed mixes and sweet feeds. Then build your bucket with super-fibres (e.g., unmolassed sugarbeet pulp or soybean hulls) plus added oil for calories. Many ex-racers do best on a high-oil cube or a soaked, low-starch conditioning feed:Allen & Page Soothe & Gain: only 14% combined starch and sugar, yet high in calories (13.25 MJ/kg), making it suitable for ulcer-prone or fizzy horses needing condition. The manufacturer advises avoiding barley or molasses alongside it to prevent intolerance or behavioural issues (Allen & Page).Baileys Ease & Excel: a high-fibre, high-oil, low-starch conditioning feed designed for stressy Thoroughbred types out of training (Baileys).GWF Fibregest: less than 10% total starch and sugars; use as a non-heating fibre base or topper to add condition without spikes.Cubes tend to contain less starch than a mix of a similar nutrient specification so, if your horse is prone to being a bit fizzy, which is fairly typical of Thoroughbreds out of training, feed a cube rather than a mix. Baileys Horse Feeds Nutrition Team (Baileys)Layer in fats such as micronised linseed or soya oil for slow-release calories (remember: oil delivers 2x the calories of cereals). Introduce oil gradually over 23 weeks and balance vitamin E if you feed higher oil levels.Quick tip: If a feed bag lists cereals (barley, maize, oats) or molasses high on the ingredient list, its likely to heat your horse more than a super-fibre or high-oil cube will.Conditioning ex-racers without the fizzUse highoil, lowstarch conditioning cubes or soaked feeds to add weight without lighting the fuse.Many UK ex-race Thoroughbreds come out of training lean and bright-eyed and they often stay that way when stabled more over winter. The goal is to increase calories without escalating behaviour.Feeds like Baileys Ease & Excel or similar conditioning cubes deliver calories via fibre and oil instead of cereals. For ulcer-prone horses, soaked low-starch options such as Soothe & Gain (14% combined starch/sugar) add safe energy and promote better chewing and hydration. Pair your bucket with ad-lib hay/haylage your most important conditioning tool and add super-fibres (unmolassed beet pulp) if you need a further lift.Pro tip: If you choose Soothe & Gain, dont feed anything with barley or molasses alongside it the Allen & Page nutrition team explicitly warns this can trigger intolerance or behavioural blips (Allen & Page).Support the digestive tract with a broad-spectrum balancer or probiotic if feed or management has changed recently. Youll find proven options in our curated range of horse supplements for digestion and calm, including popular UK brands such as NAF.Support the gut first, then consider calming supplementsFix forage and starch first, then add targeted calmers if needed.Once the base diet is right, some horses benefit from calmers containing magnesium, Ltryptophan or calming herbs like chamomile. In the UK, reputable calmers typically cost 2040 for 1.53 kg tubs a monthly top-up for many horses. Choose products with clearly listed active ingredients and introduce them only after youve addressed forage access, starch load and turnout.Remember: a calmer cant outrun a hot, cereal-heavy ration. Its a finishing touch, not a fix. Our customers often find that moving to super-fibres and oil removes most of the fizz, while a targeted calmer simply smooths the edges for competitions or box rest. Explore bestsellers in our supplements collection and filter by calming to compare options from leading UK brands such as NAF.To get the best results from Soothe & Gain, please make sure that you do not feed any other products that contain barley or molasses, as these ingredients can cause feed intolerance or behavioural problems. Allen & Page Nutrition Team (Allen & Page)UK winter management to keep Thoroughbreds chilledIn cold, wet months, rely on fibres central heating and turnout to calm energy rather than heating feeds.As UK temperatures drop and rain sets in, stabling increases and so can stress. Double down on fibre (adlib hay or haylage) and keep meals small and frequent to avoid starch slugs. Hindgut fermentation generates heat, so you can reduce reliance on cereal mixes while staying warm under rugs.Comfort equals calm. Rug appropriately and adjust weight as weather swings from damp chill to brief mild spells. For outdoor time, pick robust, breathable layers from trusted brands in our WeatherBeeta rug range or explore broader options in turnout rugs. In the stable, choose insulating, well-fitted options from our stable rug collection to keep muscles warm for training the next day.When hacking on gloomy afternoons, stay safe and visible with our rider and horse hivis favourites. Couple that with consistent routines turnout, work, forage, then rest to dial down anxiety in sharp TBs.How to transition feeds safelyChange feeds over 710 days, increasing fibre/oil while cutting starch to protect the gut and behaviour.Shift a quarter of the ration every 23 days until you reach your target bucket. Keep meal sizes modest (ideally under 2 kg per feed for a TB) and feed at least two, preferably three to four, small feeds daily if extra calories are needed. Introduce oils slowly, and soak beet pulp or specialised low-starch feeds exactly as directed for hydration and safety.Watch for early warning signs of digestive discomfort girtiness, reluctance to eat, mild colic signs or loose droppings and pause changes if they appear. If youre using Soothe & Gain, do not pair with barley or molasses as per the manufacturers guidance. Ensure fresh water is always available, especially with soaked rations.Monitoring progress and when to seek helpTrack weight, behaviour, droppings and appetite weekly; involve your vet if you suspect ulcers or sudden behaviour change.Keep a simple log: body condition score, girth measurements, how the horse feels to ride or handle, appetite, manure consistency, and any signs of stress. Many ex-racers improve within 24 weeks of moving to a fibre-and-oil plan, but some need veterinary input especially if you see repeated girthiness, teeth-grinding, cribbing or intermittent colic. Discuss gastric ulcer risk with your vet and follow welfare guidance from UK bodies like the BHS.At Just Horse Riders, we recommend pairing nutrition changes with consistent management: daily turnout, clear routines, careful rugging, and steady work. If youre competing, consider packing a calmer from our supplements range and check your tack fit while youre at it. A comfortable, dry horse is nearly always a calmer horse.FAQsWhy does my anxious TB get more excitable after hard feed?Starchy grains cause blood glucose and insulin spikes that can trigger hyperexcitability. Switch to fibre and oil as your main energy sources first, then reassess behaviour.Can I feed oil to calm a hot Thoroughbred in UK winter work?Yes. Oils such as soya or linseed provide slow-release energy and roughly 2 times the calories of cereals, helping maintain condition in cold months without adding fizz.Whats the first feed to cut for a fizzy horse?Eliminate high-sugar, high-starch concentrates e.g., sweet feeds, molassed mixes and barley and replace with super-fibres like unmolassed beet pulp plus a high-oil cube.Do calming supplements work without diet changes?No. Calmness starts with adlib forage and a low-starch ration. Magnesium, Ltryptophan and herbal blends can help only after the base diet and management are corrected.How much forage for a calm TB at a UK livery yard?Provide adlib hay or haylage where possible. If you must manage intake, use small-hole nets or multiple nets and avoid long fasting periods to keep the stomach buffered.Are cubes better than mixes for ex-racers?Yes. Cubes generally contain less starch than similar-spec mixes, reducing the risk of fizz in Thoroughbreds transitioning to ridden work.What else can I do in winter to keep my TB chilled?Maximise forage, maintain turnout, use appropriate rugs, and keep routines steady. For safety on dim hacks, kit out with rider and horse hivis and ensure rugs fit well browse proven options from WeatherBeeta and our wider turnout rug collection. Shop the Essentials Everything mentioned in this guide, ready to browse. Shop SupplementsShop NAF SupplementsShop Turnout RugsShop Stable RugsShop WeatherBeeta