Managing pastures for sheep
The pasture (or range) resource is often the most neglected part of the sheep
enterprise, yet it usually provides the majority of nutrients
to the stock. Pasture that is properly managed has
the potential to minimize feed costs and increase profits. Pasture
is the most natural diet for sheep and other ruminant animals.
Though pasture is not without its own risks, fewer digestive problems
are usually encountered when sheep and lambs spend the majority of their time grazing.
A pasture can be comprised of many different kinds of plants.
Which species to plant depends upon the purpose of the pasture,
the climate, and soil type. Soil survey maps can help with the
latter. The best pastures usually contain a mixture of grasses
and legumes. Commercial pasture mixes usually contain several grass and legumes and sometimes forbs.
Cool season grasses
In many climates, cool season grasses form the basis of most sheep pastures. Cool
season grasses are annual or perennial plants that begin growth
during the fall or winter and grow to spring or early summer.
Cool season grasses are not damaged by sub-freezing temperatures.
However, they go mostly dormant during hot weather. Common cool season
grasses include orchardgrass, Kentucky bluegrass, tall fescue,
timothy, reed canarygrass, ryegrass, brome grasses, and wheat
Tall fescue is the most important cool season grass in the United
States. Most tall fescue is infected with a fungal endophyte
that reduces performance in grazing animals and causes reproductive
problems in horses. Sheep appear to be less affected by the
endophyte than cattle and horses. Animal performance is superior
on endophtye-free fescue, but plant persistance suffers. MaxQ
tall fescue contains a non-toxic endophyte which improves animal
performance while maintaining plant performance.
Tall fescue is the most desirable grass to stockpile for late
fall and winter grazing. Unlike the summer forage, fall-saved
fescue is palatable and high in digestibility. Forage quality
losses after frost are less for fescue than other forages. Endophyte
toxicity of stockpiled fescue declines with time.
Legume plants are known for their ability to fix atmospheric nitrogen.
Legumes have a higher protein content than grasses. They fall
into two classes: forage and grain. Forage legumes include alfalfa,
clovers, birdsfoot trefoil, lespedezas, Sunn hemp, and vetch. Grain legumes
include beans, peas, lupins, kudzu, and peanuts. Pasture legumes
improve summer pasture productivity.
Legume pastures (alfalfa and clover) are also a common cause of bloat.
The phytoestrogens contained in some pasture legumes (e.g. red
clover) can cause a decline in ewe fertility. Newer cultivars have greatly reduced this risk.
The high tannin content of sericea lespedeza gives it an anitiparasitic
effect. Fecal egg counts tend to be lower among small ruminants
grazing sericea lespedeza pastures, as adult worms lay fewer
eggs and the eggs that are produced have reduced hatching ability.
Though it shows great promise for helping to control internal
parasites in sheep and goats, sericea lespedeza is classified
as a noxious weed in some states.
Warm season grasses
Warm season grasses are annual or perennial plants that begin
growth during the spring, and grow to summer or fall until frost.
Common warm season grasses include bahiagrass, bermuda grass,
crabgrass, eastern gamagrass, big bluestem, indiangrass, switchgrass,
sudangrass, and pearl millet. Most native grasses are warm season
grasses. Sheep have generally not performed as well on warm
season grasses as cattle. Warm season annuals are usually favored for sheep.
An annual is a plant that completes its life cycle in one year.
Annuals must be planted every year in order to produce forage
for livestock feed. Summer annuals complete their life cycle
between spring and fall. Summer annuals include crabgrass, pearl
millet, sorghum, sudangrass, and sorghum x sudangrass. Winter
annuals complete their life cycle between fall and spring. Winter
annuals include wheat, barley, winter oats, rye, and triticale
(rye x wheat).
Brassicas are annual crops which can be grazed by sheep. They
include rape, kale, swede, and turnips. They are most commonly
used to extend the grazing season. Performance on brassicas
is improved if dry hay is offered. Lamb performance on brassicas
When properly managed, small grain crops can be used for grazing
by sheep and other livestock. Small grains can provide excellent
pasture in the fall and early spring. The effect of livestock
grazing on small grain yields ranges from yield reductions to
increases in yield.
Forbs are non-grasslike, non-woody, flowering herbaceous plants.
Forbs are commonly called weeds. They may be classified as annual
or perennial, warm season or cool season. When grazing a mixed
sward, sheep prefer forbs. Sheep's preference for forbs makes
them well-suited to landscape management.
Browse includes buds, twigs, leaves, fruit and flowers of woody
plants (trees and shrubs). While sheep will eat varous browse
species, goats are best known for choosing these types of plants.
Crop residues are the materials left in a field after the crop
has been harvested. Residues include stalks and stubble, leaves,
and seed pods. Crop residues offer a low-cost feeding alternative
for sheep, while sheep grazing helps to control pests by disrupting
insect life cycles.
Planning for a successful pasture establishment should begin
months in advance. It can take years to correct severe soil
acidity. If lime is needed, it should be applied six to 12 months
prior to seeding.
Different seeding methods can be used to establish a pasture:
drilling, cultipacking, and broadcasting. No-tillage involves
using herbicides to kill the existing vegetation and then seeding
directly into the residue. The seed bed is usually prepared
by hay removal or hard grazing
The best time to establish cool season grasses is in the late
summer and early fall. Spring plantings have enough moisture
for seed germination, but weed pressure is high. Warm season
grasses should be planted in late spring to early summer after
the soil temperature has reached 65°F or above. Seeding
rates depend upon the plant species and seeding method. Certified
seed is recommended.
Legume seed may need to be innoculated with the proper bacterial
strain. New seedings should not be grazed until the plants have
developed sufficient root systems. If you can easily pull a
plant from the ground, its root system is not sufficiently developed.
Pasture renovation is when you "renew" a pasture by
introducing a desired forage species into the existing plant
stand. It should be done on a regular basis, as most legumes
tend to be short-lived in a pasture. Overgrazing, poor fertility,
and other adverse conditions tend to favor grass plants over
Frost seeding is a common method of pasture renovation. This is
when seed is broadcast into existing pastures during the late
winter or early spring when the soil freezes at night, but thaws
during the day.
Maintaining a pasture is similar to maintaining a car. If you
want good, long-term performance of your pasture, you need to
take steps to properly maintain it. Soil sampling a minimum
of every three years is a must. Lime and fertilizer should be
applied according to soil test results. Excess lime can cause
mineral deficiencies. Excess fertilizer pollutes ground water.
Pastures which are composed of predominantly grass plants should
receive nitrogen fertilizer every year. There are numerous sources
of inorganic and organic nitrogen. Sheep grazing pastures fertilized
with poultry litter or pig manure may be at increased risk for
copper toxicity. Pasture which contain 30 percent or more legumes
usually do not require nitrogen fertilization.
Broadleaf weeds can be controlled with herbicides and mowing.
Controlled grazing and proper soil pH will also help to surpress
Numerous plants can be poisonous to sheep. Toxicity usually
depends upon the growing conditions and stage, plant part, and
amount consumed. As a general rule, sheep usually avoid poisonous
plants. Problems arise when desirable forages are scarce and
poisonous plants are abundant.
The effects produced by the ingestion of poisonous plants are
extremely variable and depend upon the poison consumed in the
plant. Some poisonous plants cause rapid death. Others produce
gastro-enteritis or cause nervous symptoms or locomotion problems.
Treatment is usually unrewarding.
<== SHEEP 201 INDEX