How to Transition Your Horse to a New Feed Safely
Changing your horse's feed might seem straightforward — swap the old bag for a new one and move on. But if you've ever dealt with a colicky horse at 2 a.m., you know that the equine digestive system doesn't tolerate sudden changes well.
Whether you're upgrading to a higher-quality feed, adjusting for a change in workload, accommodating a health condition, or simply switching brands because your usual product has been discontinued, how you make the transition matters just as much as what you're transitioning to.
This guide walks you through the safest, most effective way to transition your horse to a new feed — step by step — so you can avoid digestive upset and keep your horse healthy and happy.
Why You Can't Just Switch Feeds Overnight
Horses are hindgut fermenters. Unlike dogs or humans, they rely on billions of specialised microorganisms in their cecum and large intestine to break down fibre and extract nutrients. These microbial populations are specifically adapted to whatever your horse has been eating.
When you suddenly change the feed, the existing microbes can't efficiently process the new ingredients. This leads to:
- Incomplete fermentation of feed, producing excess gas
- A rapid shift in gut pH, which can kill beneficial bacteria
- A release of endotoxins from dying bacteria into the bloodstream
- Colic, ranging from mild discomfort to life-threatening impaction or gas colic
- Laminitis, triggered by toxins that enter the bloodstream from a disrupted gut
- Diarrhoea or loose droppings as the digestive system struggles to cope
The microbial population in your horse's gut needs time — typically 10 to 14 days at minimum — to adjust to a new feed source. Rushing this process is one of the most common and preventable causes of digestive problems in horses.
When Do Horses Need a Feed Change?
There are many legitimate reasons to transition your horse to a new feed:
Changes in Workload or Activity Level
A horse moving from light hacking to competition work may need more energy-dense feed. Conversely, a horse being retired or turned out for the winter may need fewer calories to avoid weight gain.
Age-Related Adjustments
Senior horses often need specially formulated feeds that are easier to chew and digest. Young, growing horses have different protein and mineral requirements than mature adults.
Health or Metabolic Conditions
Horses diagnosed with conditions like Equine Metabolic Syndrome (EMS), Cushing's disease (PPID), or gastric ulcers may need a low-sugar, low-starch diet or other specific nutritional adjustments.
Seasonal Forage Changes
When pasture quality changes with the seasons, or when you switch from one batch of hay to another, the hard feed may need adjusting to maintain balanced nutrition.
Product Availability
Sometimes the feed you've been using gets reformulated, discontinued, or becomes unavailable. A switch becomes necessary, not optional.
Regardless of the reason, the transition process remains the same.
Step-by-Step Guide to a Safe Feed Transition
Follow this proven method to minimise the risk of digestive upset.
Step 1: Evaluate Your Horse's Current Diet First
Before introducing anything new, take stock of what your horse is currently eating — including forage, hard feed, supplements, and any treats or extras. Understanding the full picture helps you make smarter choices about what to change and why.
This is an excellent time to consider analysing your horse's diet with a professional tool to identify any existing imbalances or gaps. You may discover that a full feed change isn't even necessary — sometimes a simple supplement adjustment achieves the same goal.
Step 2: Choose the Right New Feed
Select a feed that's appropriate for your horse's age, breed, workload, body condition, and any health issues. Read the label carefully and pay attention to:
- Energy (calorie) content — usually expressed as digestible energy (DE) in MJ/kg
- Starch and sugar levels — especially important for metabolically sensitive horses
- Protein percentage — should match your horse's life stage and workload
- Feeding rate — the manufacturer's recommended daily amount to ensure balanced vitamin and mineral intake
If you're unsure which feed is right, consult an equine nutritionist or your vet.
Step 3: Follow the 14-Day Transition Schedule
The gold standard for feed transitions is a gradual changeover across 14 days. Here's a clear schedule you can follow:
| Days | Old Feed | New Feed |
|---|---|---|
| 1–3 | 75% | 25% |
| 4–6 | 60% | 40% |
| 7–9 | 40% | 60% |
| 10–12 | 25% | 75% |
| 13–14 | 0% | 100% |
This allows the gut microbiome to gradually adapt to the new feed's ingredients, fibre sources, starch levels, and fat content.
Important: These percentages refer to weight, not volume. Different feeds have different densities, so always use a kitchen scale or feed scale rather than relying on scoops.
Step 4: Maintain Consistent Forage
During a feed transition, keep your horse's forage (hay or haylage) as consistent as possible. Changing both forage and hard feed simultaneously doubles the stress on the digestive system.
If you must also change forage — for example, when transitioning from hay to haylage, or receiving a new batch of hay — stagger the changes. Transition the forage first over 7–10 days, then begin the hard feed transition.
Step 5: Monitor Your Horse Closely
Throughout the transition period, keep a close eye on your horse for any signs of digestive disturbance:
- Droppings: Look for changes in consistency, colour, frequency, or smell. Loose droppings or diarrhoea are early warning signs.
- Appetite: A sudden loss of interest in feed can indicate discomfort.
- Behaviour: Watch for signs of abdominal pain — pawing, looking at the flanks, lying down more than usual, restlessness, or rolling.
- Water intake: Changes in drinking habits can signal digestive stress.
- Body condition: Monitor weight and body condition score throughout and in the weeks following the transition.
If you notice anything concerning, slow the transition down. Go back to the previous ratio for a few extra days before moving forward again.
Step 6: Adjust the Pace if Needed
Not every horse transitions at the same speed. Horses with sensitive stomachs, a history of colic, or metabolic conditions may need a longer transition — up to 21 days or more.
On the other hand, if you're switching between two very similar feeds from the same manufacturer (for example, moving from a low-energy to a medium-energy version within the same product range), you may be able to transition slightly faster. But even then, a minimum of 10 days is wise.
Special Considerations for Different Transitions
Transitioning to a Higher-Starch Feed
If you're moving to a feed with significantly more starch (for example, switching from a fibre-based feed to a cereal-based competition mix), take extra care. High-starch feeds are more likely to cause hindgut disturbance if introduced too quickly. Consider extending the transition to 21 days and splitting the daily ration into smaller, more frequent meals.
Transitioning from Pasture to Hard Feed
Horses coming off good pasture and being stabled or yarded may need a complete dietary overhaul. Introduce hay first, allow the horse to settle into the new routine, and then begin adding hard feed in small amounts over two to three weeks.
Transitioning a Senior Horse
Older horses often have reduced digestive efficiency and may be more susceptible to colic. Extend the transition timeline and consider soaking the new feed to make it easier to chew and digest during the changeover period.
Switching Supplements
Even supplements warrant a gradual introduction. If you're adding a new supplement — particularly oil-based supplements or those containing prebiotics or probiotics — start with a quarter of the recommended dose and increase over 7–10 days.
Common Mistakes to Avoid
Even well-intentioned horse owners sometimes make errors during a feed change. Here are the most common pitfalls:
- Rushing the process: By far the most common mistake. Two or three days is not long enough for a full transition.
- Eyeballing portions: Feed by weight, not volume. A scoop of one feed can weigh significantly more or less than a scoop of another.
- Changing everything at once: Don't switch feed, forage, and supplements simultaneously. Stagger the changes so you can identify the cause if problems arise.
- Ignoring the manufacturer's feeding rate: Many feeds are formulated to deliver balanced vitamins and minerals only when fed at the recommended rate. Underfeeding a balancer or premixed feed means your horse may miss out on essential nutrients.
- Not accounting for forage: Hard feed is only part of the diet. Forage should make up the majority of your horse's daily intake — ideally a minimum of 1.5% to 2% of body weight in dry matter per day.
- Failing to provide constant access to fresh water: Adequate water intake is essential for healthy digestion, especially during dietary changes.
When to Call the Vet
Most feed transitions go smoothly if managed properly. However, call your vet immediately if your horse shows any of the following during or after a feed change:
- Persistent or worsening colic signs (rolling, pawing, sweating, elevated heart rate)
- Refusal to eat for more than 12 hours
- Severe or watery diarrhoea lasting more than 24 hours
- Signs of laminitis (reluctance to walk, shifting weight, heat in the hooves, increased digital pulse)
- Significant behavioural changes or lethargy
These symptoms may indicate a serious reaction that requires veterinary attention.
The Bottom Line
Transitioning your horse to a new feed doesn't have to be stressful or risky — but it does require patience and planning. A minimum 14-day gradual changeover gives your horse's gut microbiome the time it needs to adapt, dramatically reducing the risk of colic, laminitis, and other digestive problems.
Remember: the equine digestive system evolved to process a consistent, forage-based diet with very little variation. Every change we make as managers goes against that evolutionary programming, so taking it slow is always the right approach.
Take the time to evaluate your horse's full diet before making changes, follow the step-by-step transition schedule, monitor your horse closely throughout, and don't hesitate to slow down or seek professional advice if something doesn't look right. Your horse's gut will thank you.