Energy: Buzz Word or Buzzy Horse?
Keep a close eye on your spring pastures
to avoid weeds and possible equine health problems.
By Edgar
A.. Ott PhD, PAS
University of Florida Department of Animal Sciences,
Institute of Food and Agricultural Sciences
Spring comes to the Southeast at different
months. In some areas, spring arrives in February, while in
other areas it doesn’t
show up until May or June. Perennial grass pastures respond to
increased temperatures and moisture with a flush of new green
growth. If the soil has been properly nourished, that growth
provides a rich source of nutrients to the horse. Capitalizing
on that asset is a challenge to every horse owner.
Spring grass growth can have 65% as much energy as oats and more
than alfalfa hay on a dry matter basis. It is also a rich source
of protein and minerals (Table 1). Remember that these are typical
figures and can vary widely, depending upon soil fertility, moisture
and maturity. Although the nutrient content of the spring growth
on a dry matter basis is very impressive, this growth also has
a lot of water in it (sometimes as high as 80%), so the animal’s
ability to meet his/her nutrient requirements from the forage
might be limited
by the ability to consume enough dry matter.
The flip side of this restriction is that this grass usually
has a high concentration of soluble carbohydrates (sugars). Overeating
this forage can result in nutritional laminitis due to excessive
carbohydrate intake. Managing the intake of spring grass is very
important.
When you look out over the pasture in the spring, the green might
convince you that winter is gone and with it the need to feed
hay. Not yet. If you walk the pasture you might find that the
green is only tiny shoots of grass mixed with a flush of spring
weeds. Continue to feed hay until the horses start refusing
the hay. This will get you through the transition period and
the first part of the early spring grass growth. Horses that
are exposed to this smorgasbord continually will usually not
overeat the grass and will meet part of their dry matter needs
with both the pasture and the hay. The hay serves one other
function. Fresh green grass is very laxative. Hay will slow
down the passage rate in the digestive tract and increase the
digestion of the forage.
Stalled horses present another challenge. Because they are not
out on the grass continuously, care must be taken to not let
them overeat the spring grass when they are turned out. Fill
the horse with hay before turning him out. Restrict his grazing
time to ensure that he does not overeat. An hour might be suitable
the first day. Gradually increase the time but be sure to fill
him with hay each day before he is turned out. An aggressive
grazer can consume a lot of nutrients in a four-hour turnout.
Poisonous plants
Along with the flush of spring grass, you might get a some poisonous
plants. Although most of the poisonous plants that grow in
horse pastures are not very palatable, they will be consumed
if the forage available to the animal is inadequate. Drought
is often the cause of poisonous plant intake. Be sure to feed
plenty of hay during drought conditions.
Many of the poisonous plants of concern to horse owners in the
Southeast are transported by birds. Watch along fence rows for
Nightshade, which is distributed by bird manure. This plant looks
like a tomato plant with small black berries. Tomatoes, peppers
and Nightshade are all in the same family. Pull Nightshade and
other annual plants that might be toxic and discard them where
livestock are not present.
Showy crotalaria is an upright plant with multiple yellow flowers.
It is easiest to identify when it is mature enough to flower.
Crotalaria is common in fields that have been renovated. Turning
the soil brings seeds to the surface that might have been dormant
for years. Mowing and spraying will suppress the plant, but the
best solution is to pull and discard the plant when it is old
enough to identify.
Other toxic weeds showing up in pastures: jimpsonweed, purple
rattlebox, bitterweed, Carolina-jessamine, Chinaberry, bagpod
or coffee weed, pokeweed, bracken fern, castor bean, black cherry,
Carolina laurel-cherry, Johnson grass and cocklebur. Most of
these will be in the fence rows.
Care should also be taken to keep horses away from some ornamentals.
Ornamental plants that are known to be toxic to livestock include:
boxwood, hydrangea, lantana, castor-bean, elephant’s ear,
oleander, Easter lily, and poinsetta.
Well established perennial grass pastures will suppress the establishment
of poisonous weeds. Mowing the pasture on a regular interval
will also suppress or kill most poisonous plants. Fence rows
and any area where the established sod is destroyed are the most
likely areas for poisonous plants to develop. A regular walk
along the fence will let you see and destroy these plants. Pulling,
cutting and spraying are useful control techniques.
Editor’s Note: A thorough online listing of poisonous plants
in the Southeast (including photos of each plant) can be found
online at: www.caf.wvu.edu/~forage/library/poisonous/index.htm
References:
West, E. and M. W. Emmel. 1995. Plants that poison farm animals.
Fl Ag Exp Sta Bulletin 510A