Supplementing Fading Pastures

As Autumn settles in, the composition of pasture grasses begins to change. The horses are still interested in grazing, and grasses may still largely be green, but the nutrition is not the same.

All grasses have a natural growth cycle and preferred growing conditions  during which they will take a few weeks to grow to full height, develop and then drop seed.  The stage of active growth and before the grass has set seed is when hay should be cut for peak nutritional value.

After full height is reached and seed begins to form, the caloric value, carbohydrate level and protein in the plant start to drop.  Fiber and lignin begin to rise, decreasing digestibility overall. Mineral levels may drop and the minerals present may be less bioavailable because of complexation with fiber.  Levels of vitamin E and fat progressively fall.  The fat loss is almost exclusively  the more fragile omega-3 fats.

For horses being maintained on pasture, the signs of declining nutritional value include:

  • Weight loss
  • Loss of “bloom” (duller, dry coat)
  • Poor hoof quality
  • Appearance of hoof abscesses
  • Low energy
  • Slowed growth in young animals

Horses with poor hind gut function may show a distended abdomen, increased gas and/or loose manure or increased free fluid with manure.

It’s better to start supplemental feeding before you see any of these signs. Offer hay in a covered feeder or in hay bags in shelters. When pasture quality is adequate, they will eat very little or ignore it. A growing interest in hay is a strong indicator pasture nutrition is lacking.

All horses should receive vitamin E, 1000 to 2000 IU/day, preferably in an oil base.  Begin supplementing a high omega-3, flax based product at 2 to 6 oz/day. Horses on mature stands of grass should all be supported with an essential amino acid supplement of L-lysine, D,L-methionine and L-threonine.  As the pasture ages and begins to lose the bright green color, a concentrated quality protein supplement based on soy and whey should be added if supplemental feeds are not meeting protein requirements.  When in doubt about protein and fiber levels, a short pasture analysis can be obtained very inexpensively. Ask your local agricultural extension agent.

If you know when and what to supplement, your pastured horses can keep that Spring glow of health all year long.

Eleanor Kellon, VMD


About Dr. Kellon

Graduate of University of Pennsylvania Veterinary School. Owner of Equine Nutritional Solutions,, industry and private nutritional consultations, online nutritional courses. Staff Veterinary Expert at Uckele Health and Nutrition.
This entry was posted in Equine Nutrition. Bookmark the permalink.

4 Responses to Supplementing Fading Pastures

  1. mary seymour says:

    This has been very helpful and explains some things I noticed but didnt understand the cause . Thank You .

  2. Pat Gauvreau says:

    Hi Dr. Kellon,
    Thanks for this information. It answered a problem Ive been having with my horses since introducing new low sugar hay this fall. They both have loose manure and one of them also has free fluid with manure as well. What would I feed for improved hind gut?

    • Dr. Kellon says:

      The first thing to try is feeding a prebiotic food such as beet pulp or psyllium husk. A broad spectrum probiotic with yeast and cellulase activity, like Uckele Absorb-All, could also help.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.