Fact Sheet
020SA
All Horses
(Dressage / Hacks / Show
Horses / Racing / Harness)
Keeping Horses on Small Acreages
By Dr. John Kohnke BVSc RDA
The Horse at Pasture
Over the past 20 years, many owners of pleasure and equestrian horses have moved onto a 5 acre (2 hectare) block in rural
subdivisions surrounding a city or town. The combination of drought and high stocking rates has increased the need to rely
less on grazing and more on “hard” feeds and hay to maintain their horses. Over the last 15 years, the demand for hays and
hard feeds has doubled, largely as a result of the increased horse numbers on semi-urban properties. There has also been
a change in feeding attitudes due to the wide availability of prepared, complete feeds.
Grazing Habits
Horses, by nature, are selective feeders, choosing pasture and species that they find palatable, leaving other plants that they
decide are less palatable. Horses are always hungry, and find enjoyment in eating, and because of their digestive structure,
they are almost continuous grazers, eating for up to 21 hours per day when at pasture. Horses rarely stand still to graze,
they graze “on the move”. As a horse grazes, it bites off a mouthful of pasture, taking one or more steps whilst it is chewing,
before taking the next mouthful. Exercise in this way is important to maintain efficient digestive movement and action.
Horses damage or spoil around 7.5% of their available grazing area each month from hoof damage as they walk fence lines
or congregate in gateways waiting to be fed. Spoilage by urine and manure also reduces the available grazing area in a
small paddock. Horses prefer to graze young succulent pasture between 50-150 mm in height, tending to overgraze and
damage shorter pasture and leave longer, more mature grasses. In grazed out areas, further erosion by heavy rain can
reduce the available grazing area.
Historically, horses graze on grass dominant pastures, selecting shorter young growing grass and succulent plants rather
than mature fibrous dry feed. They have a teeth structure that is suited to grazing close to the ground that can limit pasture
regrowth, as well as pick up fine sand on sparsely covered sandy soil which can accumulate in the hindgut to cause sand
colic.
Once a horse is put into work, the diet is often less reliant on pasture, and grains and stored fodder in the form of hay and
chaff must be provided to meet the increased energy needs in a less bulky feed. Unfortunately, pasture is often limited or
under-utilised as a feed source for pleasure and horses in light work. In many cases, this is due to the restricted area of
available pasture on semi-urban 2.5 hectare (5 acre) hobby farms where the largest population of equestrian and pleasure
horses are kept.
Pasture Variation
On many small acreages, it’s either a feast or famine for most grazing horses. During spring and early summer, provided it
is warm enough for the pasture to grow, regular slashing of pasture to maintain growth and delay maturity is necessary if the
pasture gets ahead of the horses. During the late summer, autumn and the onset of the colder weather winter season,
pasture alone may not provide sufficient energy and other nutrients, even at a stocking rate of one horse per hectare, or 2
horses on the average 2.5 hectare hobby farm to meet their total needs from grazing. In most cases, up to 30-40% of the
grazing area is lost to driveways, buildings, laneways, gardens and yards, and often, 2 or 3 horses effectively are restricted
to 1-1½ hectares.
Rotational Grazing
Under overgrazed conditions, plant competitiveness is reduced when pasture is unable to keep ahead of the horses on a
continuous grazing plan. Horses prefer to continue to graze and will eat out pasture when paddocks are almost bare, even
when they are given hay and hard feeds to meet their needs. Their selective grazing habits result in the more palatable,
succulent plants being eaten out. The less palatable species, which usually include weeds and dry, long mature grass are
avoided by horses, unless the horses are starving and are forced to graze. This is one of the problems of a small acreage
‘all horse’ property where other less selective grazers, such as cattle, cannot be rotated through the pasture to clean-up the
“leftovers” that horses avoid.
Rotational grazing can increase pasture productivity by 50% because plants are not eaten down and made less
competitive if horses are moved on a 2-4 day cycle over a 10 day period to allow pastures to regrow and maintain
their competitiveness.
‘Lawns’ and “Roughs”
Besides being selective in their choice of food, horses by their nature, also develop very defined areas for grazing (called
“lawns”) and pass their dung on rank areas (called “roughs”) of a paddock that they create as they graze on more succulent
pasture species. Often the “roughs” consist of less palatable plants and with the higher density of droppings and recycled
minerals and nitrogen. These plants and weeds are encouraged to grow and become rank or dominant over the remaining
pasture.
In a normal horse pasture, after a 6 month period of continuous grazing, up to 52% of the total pasture area in the paddock
can develop into non-grazing pasture with roughs (31%), camping areas, play and rolling areas, fence line walking and
‘hassling the neighbouring horse’ areas as well as waste areas around feed bins and gateways (21%), leaving only 48% of
the area to be grazed.
Young horses tend to walk more in search of companionship than older horses and a single horse in a one hectare paddock
may walk up to 7kms daily when grazing or seeking companionship.
Paddock Shape
Paddock shape also has an effect on the density of ‘horse traffic’ as well. Horses are more likely to walk the fence lines in
rectangular paddocks, as compared to a square paddock of the same area, although the centre of a square paddock is likely
to be overgrazed. You can actually save around 25% of the cost of fencing a square paddock than a rectangular
paddock of the same area, because rectangular paddocks of the same area have a longer total fence length.
Obviously the position of trees, water courses, dams and topography can affect the subdivision of 5 acres into paddocks. In
stables, on the other hand, horses are more comfortable in rectangular stables as they can lie down lengthways, but
most stables are still designed as squares.
Did You Know That…
The average 500kg adult horse eats about 3750kg of dry feed as hay, chaff or dry feed and drinks 9200 litres of water over a
12 month period. It passes round 5500kg of manure (average 15kg daily) and 5000 litres of urine (average 12-13 litres daily)
onto its grazing area per year.
Nutrient Recycling
70% of the droppings and 80% of the urinary volume is passed at night. Although 80% of the electrolytes and trace minerals
are recycled back into the soil by worms, dung beetles and bacterial and fungal breakdown, acid and nitrogen compounds,
as well as odour, can become concentrated and cause ‘souring’ of the soil. This leads to the development of typical ‘horse
sick’ areas on small overgrazed paddocks. The availability of trace-elements in the soil is also reduced due to changes in pH
and compaction, also upsetting the balance required for optimum plant growth. Only renovation by opening up the soil
with a disc plough or sod seeder and spreading agricultural lime will help to recondition the soil profile and pH to a
level that encourages plant growth. However, seek advice on the application rate of lime as high pH of the soil can
reduce trace-mineral availability by growing plants.
On restricted area “hobby” farms, extra nutrients largely concentrate due to the importation of hay and other feed on the
property as supplementary feed. This may help provide useful organic matter in sandy, poorer soils, but often increases the
nitrogen and other trace-elements that can cause rank, unpalatable growth around the feeding area on heavier soils. Often
feeding areas become compacted when horses stand around eating in wet weather, facilitating ‘run off’ to the edges of the
feeding area. In turn, this provides more moisture for ‘fringe’ dwellers, such as weeds, increasing the rank areas and
“roughs” around feeding areas.
Weed Growth
As a horse owner, you may have wondered why the small flowered mallow (known as small marshmallow), wild turnip,
fireweed, capeweed, fat hen, paterson’s curse and thistles seem to grow on the edges of bare areas in horse paddocks, and
around the fence lines?
These species have very small seeds that can be eaten with feed and passed in horse manure for up to 13 days after being
consumed in hay, although most are passed out in 4 days. Small weed seeds, which have a tough outer seed coat, miss
being chewed by the horse and are not digested in the small or large intestine because of their resistant protective coat,
resulting in a 95% chance of germination when passed in the droppings.
When eaten by a cow or sheep, which chew their cud, only 5% of the weed seeds are viable in the droppings as most are
crushed up during the regurgitation and ruminating process. They float on the surface of the rumen and are the first to be
returned to the mouth for grinding as a cow or sheep chews its cud.
The increased moisture in low spots and build up of nitrogen and fertility from the droppings, which are washed to the edges
during rain, encourages rank, weedy growth. Because their dung contaminates this area, horses will often not graze the
pasture, unless forced to do so by reduced pasture elsewhere.
Quarantine Newly Introduced Horses
When horses are introduced from another property, or you buy a new horse, it is good husbandry to worm it out and leave it
in a yard and hand feed it for 24-36 hours to pass out worm eggs in its droppings prior to being turned out onto your own,
hopefully, worm free pasture. If the horse was grazing on a weedy pasture with mature small seed weeds, then allow a
minimum 4 days, and preferably up to a fortnight of “quarantine” period to avoid weed spread onto your pastures.