Hay bales stacked in a barn loft above a wall of hanging tack
Guide · 5 min read

Basic Nutrition & Feeding Guidelines for Horses

First published September 2020 · Revised 2026Written by Kara Gardiner, Nzymes Equine Specialist

Almost every problem on this shelf traces back, sooner or later, to the feed room. Here's the foundation: how much hay a horse actually needs, the six nutrients that have to be there, and the do's and don'ts that keep small decisions from becoming big problems.

Start with the forage

Hay and grass are the main feeds.

Horses eat large amounts of hay and grass as their main source of food. In general, a horse should eat 1 to 2% of their body weight in hay every day, roughly 15 to 20 pounds. A 1,000-pound horse in light work might get 12 to 15 pounds a day; the same horse in a heavy work program may need 15 to 18.

Check the bales

When choosing, buying, or storing hay, make sure it has no fungal mold and minimal dust. Both can create health problems and contribute to potential heaves or respiratory infections; moldy hay is also how fungal pneumonia usually starts.

The six basic nutrients

Six boxes to check. Water is first for a reason.

If your hay or pellets come from a feed company, they should already balance most of these. The details still matter, and one of them gets forgotten more than any other:

1 · The most important
Water

About 2 quarts for every pound of hay eaten. On hot days, during hard work, or for a nursing mare, 3 to 4 times that. Keep the supply adequate and clean, always.

2 · The energy
Carbohydrates

The main energy source in most feeds. Starches and sugars break down to glucose in the small intestine; fiber ferments in the large intestine to release its energy.

3 · The builder
Protein

For muscle development during growth and exercise. Most adult horses need only 8 to 10% in the diet; nursing mares and growing foals need more. Alfalfa is a good source, but watch its sugars.

4 · The dense fuel
Fat

Three times the energy of any grain. A small amount of flax seed is a good source. Most premixed feeds run 2 to 6%; senior feeds may run 10 to 12%.

5 · Usually covered
Vitamins

They come in two kinds: fat-soluble (A, D, E, and K) and water-soluble (C and the B-complex). A horse foraging on green pasture usually has plenty of both. The exceptions: high-grain diets, low-quality hay, and horses under stress from travel, showing, racing, or illness.

6 · Plus the salt lick
Minerals

Body structure, electrolytes, nerves, muscle. Pasture and premixed rations usually cover them, but salt is the exception: keep a salt lick available at all times. Heavy sweaters may need electrolyte help; youngsters under 2 may need extra calcium, phosphorus, copper, and zinc.

The one to watch

Starch is where feeding goes wrong.

An overabundance of starch or high-sugar feed can cause colic or laminitis. Forages normally run only 6 to 8% starch, but under certain conditions can reach 30%. Timothy or bromegrass hay is the safer main diet: less soluble carbohydrate than alfalfa or corn.

The short version

Feeding do's and don'ts.

Do
Feed lots of high-quality forage
Manage your pastures carefully
Be prepared for hay shortages in your area
Feed a balanced diet
Be aware of special diet concerns for young or elderly horses
Feed extra calories if your horse needs them
Have salt licks available at all times
Don't
Feed poor-quality hay containing dust or mold
Allow easy keepers too much pasture time
Forget the exercise
Overfeed (a day of fasting can be beneficial)
Over-supplement
Ignore your horse's specific needs
Forget the water
What the hay can't carry

The two things processed feed leaves out.

Even a well-balanced feed program has two gaps: the live enzymes that heat processing removes, and the friendly gut bacteria that keep the whole digestive system working. These two, added to the daily feed, close them:

Sprouted Granules, 2 lb bag
Add to feed · daily

Sprouted Granules, 2 lb

The live sprouted superfood that puts back what processing takes out, supporting the body's own repair and maintenance work every day.

Bac-Pak Plus, 400 g tub
Add to feed · once daily

Bac-Pak Plus, 400 g

Digestive enzymes plus probiotics for the gut flora that ferment your horse's fiber into usable energy. The 400 g tub was made with horse owners in mind.

Both are covered by the 120-Day Worry-Free Guarantee: up to four months to see the difference in your own horse.

Good feeding isn't complicated.
It's consistent.

Questions horse owners ask
How much hay should a horse eat per day?

In general, 1 to 2% of body weight daily, roughly 15 to 20 pounds. A 1,000-pound horse in light work might get 12 to 15 pounds a day; the same horse in heavy work may need 15 to 18.

How much water does a horse need?

About 2 quarts for every pound of hay eaten, and on hot days, during hard work, or for a nursing mare, 3 to 4 times that. It's the most important nutrient of all.

Why is starch dangerous?

Too much starch or high-sugar feed can cause colic or laminitis. Forages normally run 6 to 8% starch but can reach 30% under certain conditions. Timothy or bromegrass hay carries less soluble carbohydrate than alfalfa or corn.

Does my horse need vitamin or mineral supplements?

A horse at normal weight on green pasture or a premixed ration usually gets enough. The exceptions: salt should always be available as a lick, heavy sweaters may need electrolyte support, and youngsters under 2 may need extra calcium, phosphorus, copper, and zinc.

What should I check my hay for?

No fungal mold, and minimal dust. Both can create health problems and contribute to potential heaves or respiratory infections.

Not sure what your horse needs?

Kara has managed feed programs through Saskatchewan winters.

Kara is the equine specialist on our customer care team, and she keeps her own herd fed through some of the hardest feeding country there is. Tell her what you're feeding and what you're seeing, and she'll tell you honestly where to start. Read Kara's story →

The consultation is free, and it always will be.

1-877-816-6500 · Orders & quick questions
Kara with one of her horses
Kara · Equine specialist