The golden rule for changing horse feed is simple: go slowly. The British Horse Society recommends making feed changes gradually, ideally over 10 to 14 days, and that goes for forage too. Sudden switches can unsettle the bacteria in your horse's hindgut, which is why some horses seem gassy, loose or out of sorts after a change. A slow, steady transition gives their gut time to adjust and keeps everything settled.
Autumn is peak season for changes. Grass is on its way out, hay or haylage is coming in, and many owners tweak hard feeds for winter. It's a lot for one gut to cope with at once. Here's how to make the switch smoothly, with a simple week-by-week plan you can follow.
Key takeaways
- Make feed and forage changes over at least 10 to 14 days.
- Your horse's gut bacteria need time to adapt to new food.
- Change one thing at a time, and treat a new batch of hay as a change too.
- A forage-first winter diet is the kindest option for horse gut health.
- Healthy gut bacteria make most of the B vitamins your horse needs.
How do I change my horse's feed safely?
To change your horse's feed safely, introduce the new feed in small amounts and gradually increase it while reducing the old one, over at least 10 to 14 days (BHS). Change one thing at a time, keep forage available throughout, and watch your horse's droppings, appetite and mood as you go.
A few simple habits make every switch easier:
- Change one thing at a time. If you're switching both hard feed and forage, stagger them.
- Keep forage going in. A steady supply of fibre is the gut's best friend during any change.
- Feed little and often. Smaller meals are easier to digest than one big bucket.
- Stick to your routine. Keep feed times the same while the diet changes.
- Keep a note. Jot down what you're feeding each day so you can spot anything that doesn't agree with your horse.
How long should a feed change take?
A feed change should take at least 10 to 14 days, and some horses do better with a little longer. The bigger the change, the slower you should go. Switching from grass to hay, or from one hard feed to a very different one, needs more time than moving between two similar products.
Here's a simple plan you can follow when changing a bucket feed:
| Days | Old feed | New feed | What to watch |
|---|---|---|---|
| 1 to 3 | About 90% | About 10% | Appetite and droppings |
| 4 to 6 | About 75% | About 25% | Droppings and energy levels |
| 7 to 9 | About 50% | About 50% | Behaviour and mood |
| 10 to 12 | About 25% | About 75% | Weight and condition |
| 13 to 14+ | None | 100% | Carry on monitoring |
If your horse seems unsettled at any stage, go back a step and slow down. There's no prize for finishing early.
Switching from grass to hay or haylage
Forage changes matter just as much as bucket feeds. Grass, hay and haylage are all quite different to your horse's gut. When bringing your horse in for winter, start offering hay or haylage in the field or stable while they're still getting plenty of grass, then gradually reduce turnout time. Even a new batch of hay from a different field or supplier counts as a change, so mix old and new for a week or two where you can.
Why do feed changes upset a horse's gut?
Feed changes upset a horse's gut because the bacteria in the hindgut are specialists. Different bacteria thrive on different foods. When the diet changes suddenly, especially if more starch arrives in one go, the bacterial community is thrown off balance and the hindgut can become more acidic. That's when you might see a gassy, bloated or unsettled horse.
Your horse can't digest fibre on their own. Instead, they rely on billions of hindgut bacteria to ferment it into energy. Researchers at Rutgers University explain that when concentrates are added quickly to a forage diet, starch-loving bacteria multiply and can make conditions in the hindgut more acidic, disrupting the whole microbial community (Rutgers NJAES).
The gut is also closely linked to behaviour. If your horse seems more spooky or tense after a feed change, that usually isn't a coincidence. We explain the gut-brain connection in our guide to how gut health links to behaviour in anxious horses. The important thing is not to reactively reach for a calmer. Give it a couple of weeks and give your horse's gut time to settle after dietary changes have come into effect before deciding it's not a good switch or to add a calming product into the mix.
What should I feed my horse in winter?
Build your horse's winter diet around forage. Good-quality hay or haylage should make up most of what they eat, with a bucket feed or balancer on top only if they need extra energy, vitamins or minerals. During winter, feeding horses well is less about fancy extras and more about keeping fibre going in all day.
- Forage first. Most horses need forage of at least 1.5% of their bodyweight each day (BHS). For a 500kg horse, that's at least 7.5kg.
- Fibre keeps them warm. Digesting fibre in the hindgut produces heat, so extra hay on cold nights is like a central heating boost.
- Match feed to workload. If your horse is doing less over winter, they may need less hard feed.
- Keep an eye on weight. Fat score and weigh tape every couple of weeks and adjust as needed.
- Don't forget water. Horses often drink less in cold weather, so check troughs aren't frozen and consider offering tepid water.
Moving yards or bringing in a new horse?
Moving yards is one of the biggest feed changes of all, even if you take your usual hard feed with you. The grazing, hay, water and routine will all be different. If you can, bring a few bales of your current hay to mix with the new yard's forage, and ask about their turnout routine so you can start matching it before you move. The same goes the other way: if a new horse is joining you, ask their old yard what they were eating and change them over slowly.
Signs the winter diet needs a tweak
Once your horse is settled on their winter diet, keep checking in. A horse who's dropping condition, leaving hay, looking dull or suddenly full of beans may need a rethink. Changes in workload, weather and forage quality through the winter all affect what your horse needs, so a diet that suited them in November may not be quite right by February. Any changes you make should still be gradual.
If your horse is spending more time stabled, our guide to windsucking and winter stabling has plenty of tips for keeping stabled horses content.
What role do B vitamins play in gut health?
B vitamins help your horse turn food into energy and support normal nerve function. In a healthy horse, most B vitamins are made by the bacteria in the hindgut as they ferment fibre (Rutgers NJAES). So a settled, well-fed gut is the foundation of good B vitamin supply.
That's why B vitamins for horses and gut health are so closely linked. When the gut bacteria are balanced and well fed with fibre, they keep producing. When the gut is disrupted, perhaps by a sudden feed change, a stressful time or a period of illness, that production may be affected too.
The takeaway is simple: look after the bacteria, and they'll look after your horse. Slow changes and plenty of forage are the best ways to do that.
Your autumn feed change checklist
- Plan your changes and make one at a time.
- Switch hard feeds over a period of at least 10 to 14 days.
- Introduce hay or haylage while your horse still has grass.
- Mix old and new batches of hay where you can.
- Keep forage available as much as possible.
- Feed little and often, at regular times.
- Watch droppings, appetite, behaviour and weight.
- Speak to your vet if your horse seems unwell or uncomfortable.
FAQ
What are the signs a feed change isn't agreeing with my horse?
Watch for looser or firmer droppings than usual, a drop in appetite, gassiness, a dull mood or changes in behaviour. If you notice any of these, slow the change down. If your horse seems uncomfortable, stops eating or you're worried, call your vet straight away.
How do I switch from haylage to hay?
Haylage and hay are quite different to your horse's gut, so treat the switch like any other feed change. Start by replacing a small portion of the haylage with hay, then increase the hay and reduce the haylage over two weeks or more. Hay is drier, so make sure fresh water is always available.
Can I change my horse's feed straight away if it's the same brand?
Even within a brand, different feeds can vary a lot in fibre, starch and oil. It's best to treat any new feed as a change and introduce it gradually. If the two feeds are very similar, you may be able to go a little quicker, but slow is always safer.
A settled gut makes for a happier horse. Take your time this autumn and your horse's gut will thank you for it. If you'd like to explore further, take a look at our range of natural gut supplements.
References
- British Horse Society. Feeding horses.
- Rutgers New Jersey Agricultural Experiment Station. E375: The equine hindgut microbiome.
About the author
Alexandra Frazer, Founder of EquiNutritive, BSc Equine Science. Alexandra is the equine scientist behind EquiNutritive's all-natural equine supplements.