Feeding Horses in Spring: Balancing Fibre, Pasture Risk, and Supplements

Megan McKenzie
Oct 2
5 min read

Introduction

Spring is a critical season for horse nutrition. The shift from winter feed to growing pasture, warming days and cool nights, and the temptation of lush green grass all combine to create both opportunity and danger. A sound feeding strategy in spring must prioritise fibre, manage the risks of spring pasture, and, when needed, supplement with energy and protein feeds—ideally selecting safe and well‑balanced options such as those offered by Green Valley Grains.

Why Fibre Is Foundational

Horses are hindgut fermenters: their digestive system is adapted to handle high volumes of fibrous material (forage). Fibre maintains gut motility, stimulates chewing, supports healthy microbial populations, slows sugar absorption, and reduces digestive upsets. In spring, it is essential to keep hay or mature forage in the diet to balance lush pasture and maintain gut health.

The Risk of Spring Pasture

Spring pasture is lush but can be dangerous due to high sugar and starch levels. Risks include laminitis, colic, and metabolic disorders. Contributing factors are cool nights, sunny days, sudden diet changes, and overgrazed pastures. To reduce risks: introduce grazing gradually (strip grazing), restrict turnout during high‑risk hours, use muzzles, manage pasture height, and monitor for laminitis signs.

Here’s why:

High non-structural carbohydrate (NSC) levels: Cool nights and warm, sunny days contribute to accumulation of sugars, fructans, and starch in rapidly growing grass.
Risk of pasture-associated laminitis: Overconsumption of sugar-rich pasture can trigger a laminitic episode in susceptible horses.
Sudden diet shifts: A horse that has had limited pasture all winter may not have the microbial adaptation in the hindgut to process an abrupt influx of rich pasture.
Overgrazing and low pasture height: The lower leaf sheaths (closer to the ground) often hold more stored sugars; if pasture is overgrazed, that risk is amplified.
Time-of-day variation: NSC concentrations tend to rise during the day (peak in the afternoon) and decline overnight. Grazing in early morning (or overnight) is safer.

To reduce risk:

Introduce grazing gradually, starting with short periods (e.g. 30 minutes) and increasing slowly.
Use grazing muzzles, restrict turnout during high-risk hours (afternoon), or keep the horse on a dry lot during adverse conditions.
Mow or manage pasture to keep grasses in an actively growing stage (less sugar accumulation).
Test pasture forage or use hay known to be low in NSC (e.g. < 10–12 %) as a safer base during risky periods.
Monitor horses daily for signs of early laminitis (e.g. warm hooves, increased digital pulses, “walking on eggshells”).

In many regions, spring poses one of the highest laminitis risk windows of the year.

When Supplementary Feeding Is Needed

There are many cases when just pasturing or hay may not be enough to maintain body condition, especially for:

Performance horses in work
Mares in late pregnancy or lactation
Horses recovering from illness or weight loss
Horses on restricted pasture (to manage laminitis risk)

A supplementary grain or concentrate can help “fill the gap.” But it must be chosen and fed wisely—never at the expense of fibre, and always balanced to avoid sugar or starch overload.

When selecting supplementary grains, look for:

Moderate to low starch content
High digestibility
Good protein (or complementing protein)
A known, clean source
Compatibility with other dietary ingredients

This is where Green Valley Grains comes in. As an Australian, boutique, FeedSafe-accredited feed manufacturer, they offer a range of quality grains that can be used to create your base ration.

Some relevant products and grains:

Steam rolled (steamed & rolled) barley – by steaming and rolling, digestibility improves while still keeping fibre integrity
Lupins (cracked and steam and rolled) – a high-protein, high fibre complement; useful for balancing amino acid supply.
Oats (or steam rolled oats) – a moderate energy grain that also contributes fibre.
Black sunflower seeds – a source of fat and some protein, useful for coat condition and caloric density.

By combining these grains judiciously, one can tailor a supplementary feed mix that boosts calories and protein without overwhelming the horse’s system.

Example approach:

Using a small amount of steam rolled barley as an energy source.
Add cracked lupins to contribute protein, especially if pasture or hay protein is marginal.
Oats can be used as a “safer” grain supplement, balancing the cereal load.
Black sunflower seeds supply fat (energy-dense) and help with coat and condition without spiking insulin as much as pure carbohydrate sources.

(Note: Always check with a qualified equine nutritionist or veterinarian before formulating a custom mix.) you can contact megan@greenvalleygrains.com to find out more

Balancing the Diet: Supplements, Minerals, and Salt

Supplementary grains should not be “dumped in” without thought of the broader diet. Some key principles:

Mineral and vitamin balance - Grains are typically low in certain trace minerals (e.g. selenium, copper, zinc) and vitamins (such as vitamin E). Use a high-quality equine mineral/vitamin supplement or balancer that complements your mix.
Salt (sodium, chloride)- Horses must have free access to plain salt (white, iodised or coarse feed salt) to satisfy sodium chloride needs. Work, heat, and sweat losses can significantly increase salt demand, especially in spring turnout days. Some feed mixes provide moderate salt, but free salt should still be available.
Meal / frequency- Rather than feeding a large concentrate once daily, partition the grain into 2–4 smaller meals to lessen the glycaemic load and spread digestion demand.
Maintain a fibre base- Never replace all forage with concentrates. Even if pasture is good, horses should still have access to hay, straw, or older pasture fibre to ensure chewing, salivation, and gut buffering.
Monitor body condition- Regularly check body condition score, muscle tone, and weight (via weigh tape or scales). Adjust grain intake or pasture access accordingly.
Transition slowly- When changing feed ingredients or levels (e.g. introducing steam-rolled barley or lupins), make the change over at least 7–10 days (often more for sensitive horses).

Sample Feeding Strategy

Example for a mature horse in moderate work:- Early spring: Hay (1.5–2% BW DM) + small grain supplement- Gradual turnout: Short, early-morning grazing- Peak grass: Restricted grazing, low-NSC hay- If condition drops: Increase grains (barley, lupins, oats) and add sunflower seeds- Always: Provide salt and mineral supplements

Time / Period	Feed Strategy	Notes / Cautions
Early spring (grass just sprouting)	Maintain moderate hay allowance (e.g. 1.5–2 % of bodyweight DM) + small grain supplement (steam rolled barley + lupins)	Don’t rush to full pasture access
Gradual turnout	Begin with 30–60 min grazing in early morning; use grazing muzzle if needed	Monitor behavior, hoof heat, or soreness
Peak spring grass (rapid growth)	Restrict pasture to early morning; reduce grain slightly if condition is firm; offer low-NSC hay during the afternoon	Use fibre buffer to reduce risk
If condition falls	Increase concentrate (barley/lupins ratio) or add oats, plus sunflower seeds for healthy fat	Watch overall NSC load
Always	Offer free salt + balanced mineral supplement or balancer	Keep fibre constant; monitor BCS

Final Thoughts and Cautions

No one-size-fits-all: Every horse is different. A good feeder works in consultation with veterinarians or nutritionists.
Don’t overdo grain: Too much cereal, too fast, is a common path to colic, laminitis, or hindgut disruption.
Pasture is a resource—but a risky one in spring: Respect its power, but don’t overexpose.
Choose quality grains: Using reputable suppliers like Green Valley Grains ensures you begin with clean, Australian-grown, dust-reduced ingredients.
Balance is everything: Fibre, protein, energy, minerals, vitamins, and salt must all align for a healthy, spring-feeding strategy.