Extending the Pasture Season
by Ed Ballard, Extension Educator, Animal Systems
Feed costs represent the major cost in most livestock production
systems. Typically the cost of supplying nutrients to ruminant livestock is
much greater using harvested feedstuffs as opposed to grazing pastures or crop
residues. The primary function of a grassland farm is to convert solar energy
to marketable livestock products in the most efficient manner. The fewer steps
between the animal product and the solar energy, typically, the more economically
efficient the production systems will be.
Providing grazable forage, in a cost-effective manner to the animal,
for as many days of the year as possible should be the goal of the grazing manager.
EXTENDING GRAZING IN THE FALL AND WINTER
Several strategies can be employed to supply forage into the fall
or early winter and effectively extend the grazing season by 60 to 90 days,
thus reducing the need for stored feeds. These strategies can be categorized
into two major groups:
- stockpiling (conserving cool-season forages in late summer for use in the
fall and winter), or
- utilizing forage crops that continue to grow into the fall and early winter.
Not all cool-season species are adapted to stockpiling because
most species reduce growth in the fall because of shorter day lengths and/or
lose leaves (quality) after being frosted. Tall fescue and birdsfoot trefoil
are two forage species which are suited to stockpile management because they
continue to grow into the fall and do not lose leaves as readily as other cool-season
species after frost.
Stockpiling Tall Fescue
Tall fescue is a deep-rooted, long-lived, sod-forming grass that
spreads by short underground stems called rhizomes. It is drought resistant
and will maintain itself under rather limited fertility conditions. Animals
readily graze tall fescue during the fall and winter, but show some reluctance
to graze it during the summer months of July and August. Some of this reduced
summer palatability, which results in poor animal performance, is associated
with the presence of a fungus in the plant (endophytic). Endophyte-free varieties
are now available. Tall fescue is the best-adapted cool-season grass for stockpiling.
Tall fescue will maintain more active growth at lower temperatures
than most other cool-season grasses and so will continue to accumulate yield
later into the year. In response to shortening day length and cooler night temperatures,
tall fesuce accumulates a high level of soluble carbohydrates in both the leaves
and stem bases. With up to 20 percent of the dry weight of the plant as free
sugars, the nutritive quality of fall grown tall fescue is quite high. The heavy
waxy layer or cuticle on the leaves makes the plant more resistant to frost
damage than most other cool-season grasses.
To stockpile tall fescue, don't graze it from early to mid August
through mid-October. Cattle and sheep perform less than optimally on it during
this period. Tall fescue is also very responsive to nitrogen fertilization.
To produce a high yielding, high quality stockpile, the pasture should be grazed
or clipped fairly short and 40 to 80 pounds of nitrogen per acre applied 60
to 90 days prior to the end of the growing season. Normally, that is early to
mid-August. If soil moisture is favorable, the higher rate of N may be applied.
If the summer has been dry, application of more than 40 lb N/acre may not be
If the red clover component of a mixed fescue-clover pasture is
greater than 30 to 40 percent, it is probably not cost effective to apply additional
Some recent work has indicated that a mixture of Orchardgrass
and tall fescue can be stockpiled for early fall grazing.
Stockpiling Birdsfoot Trefoil
Birdfoots trefoil is a perennial legume adapted to production
on poorly drained, low pH soils. It can reseed itself, is resistant to Phytophthora
root rot and numerous alfalfa insects, responds well to fertilization, and does
not cause bloat in animals. Birdsfoot trefoil is well suited for stockpiling
since it holds its leaves at maturity and after frost, thus maintaining a relatively
high level of quality.
To stockpile birdsfoot trefoil, avoid grazing between September
1 and the first killing frost. This period is needed to accumulate root reserves
that improve winter survival and growth the following spring. The forage that
accumulates during the stockpiling period can be grazed anytime after a killing
FALL GROWING FORAGE
The growth of some forage species is not adversely affected by
cooler fall weather and shorter day lengths, as are many cool-season forages.
The species, which seem to grow best in the fall, are perennial ryegrass, small
grain cereal crops such as rye, wheat, oats and triticale, and certain brassica
crops like turnips, rape and kale.
Brassicas are annual crops that continue to grow during the fall
and into the winter. They are highly productive and digestible and contain relatively
high levels of crude protein. Sheep producers probably more commonly use these
than cattlemen. Early to mid-August establishment is best suited for November-December
grazing. Cattle will readily consume the plant tops and will also grub the root
bulbs out of the ground. The plants tops will typically contain 16-18 percent
crude protein and the roots are highly digestible carbohydrates. These crops
are best suited for crop rotation pastures or no-tilled into light sod. Total
dry matter yield is very variable and is highly dependent upon soil type, fertility,
time of seeding, and precipitation.
Rape is more easily managed for multiple (generally more than
two) grazings than are the other brassica species. Approximately six to ten
inches of stubble should remain after the first grazing of rape; this practice
promotes rapid regrowth. Regrowth of rape may be grazed at four-week intervals.
On the final grazing, the plants should be grazed close to ground level.
When turnips are grazed twice, the first grazing should remove
only their tops. Turnip regrowth is initiated at the top of the root, so this
part of the plant should not be removed until the second and final grazing.
Like rape, regrowth of turnips can be sufficient to graze within four weeks
of the first grazing.
When using brassica crops there is potential for animal health
problems so it is recommended that brassicas be fed in combination with other
forages or roughages such as dry hay, grass pastures, corn stalks, etc. Ruminant
diets should not contain more than 75 percent brassica forage because the fiber
content is too low for maintenance of proper rumen activity. With their high
digestibility and low fiber content, brassicas actually should be considered
as "concentrates"rather than "forage"in nutritional planning for livestock.
The use of winter cereal crops such as wheat, rye, spring oats,
or triticale can provide fall or early winter grazing opportunities. However,
certain management practices need to be modified from what is normally done
for grain production. When small grains are used for grazing, plant them three
to four weeks earlier than for grain production. Increase the seeding rate to
2 1/2 to 3 bushels per acre and apply nitrogen at the rate of 40 to 60 lb/N
per acre at planting time.
Rye will be more productive than wheat or triticale for both fall
and spring production. However, grazing quality will be better with triticale
than for rye. Spring oats seeded in the fall can be very productive but will
die out over the winter. However, with adequate fall moisture, grazing should
be available from October through December and then again in early spring for
the rye, triticale and wheat.
Stocking rate and time of grazing will be somewhat determined
by the intended use of the crop. If you are planning to take a silage or grain
harvest, grazing should only be moderate. Heavy grazing can reduce grain yields.
Moderate grazing in the fall will not result in significant silage or grain
losses provided that moisture and soil fertility are adequate. In fact, fall
pasturing can be beneficial where the small grain was seeded early and has made
excessive growth and soil conditions are dry.
Spring grazing may be started when growth resumes. If a grain
or silage crop is to be harvested, grazing should be discontinued when the plants
start to grow erect, just before jointing (growth stage). Grazing at any time
after their growing points are above the ground will injure small grain plants.
In mixed crop and livestock operations, corn and grain sorghum
stalk fields can be used to supply substantial grazing days. As grassed waterways,
terraces, and field borders become more widely used, this option becomes even
The crop residues represent about one-half of the plant dry matter
and, therefore, a field producing 120 bushel corn grain will have close to 3
to 4 tons of roughage dry matter per acre. The optimal grazing allowance on
corn crop residue fields is dependent on the weight gains necessary to obtain
a desired body condition. With low supplementation, cows can maintain bodyweight
with as little as .5 acres corn crop residues per cow per month, but may need
as much as 2 acres per cow per month if bodyweight gain is necessary.
Because grazing cattle will select the portions of crop residues
with the highest digestibility and protein concentration, needs for supplemental
feeds beyond trace mineral salt and vitamin A are likely to be minimal for the
first month of grazing. Simultaneous grazing of stockpiled grass or legume forages
(late summer growth) may also supply protein and energy and, thereby, reduce
needs for supplementation. As winter progresses and crop residue quality decreases
because of grazing selection and weathering, supplementation of protein and
phosphorus may become necessary.
Grazing Dormant Alfalfa
Another option that has become increasingly popular for extending
the fall grazing season has been to graze the regrowth of alfalfa hay fields
or pastures after cold weather has ensured dormancy. Usually 2 to 3 days of
successive temperatures in the 24-27 degree Fahrenheit range should be experienced
before grazing alfalfa. It is important to graze early enough to utilize the
forage while still in a leafy palatable state. If grazing is delayed until freezing
has desiccated the plants and caused most of the leaves to drop, then the cows
or sheep had just as well be kept off. An added benefit to fall grazing alfalfa
is that research and farmer experience indicates a reduction in alfalfa weevil
populations the following spring. This is due to removal of some of the stems
where weevil egg masses overwinter. Some points of concern when grazing alfalfa
hay fields are not to graze when the soil is saturated, as this will cause long
term stand damage and roughen the field. Enough stubble, 3 to 4 inches, should
be left to catch and hold snow to reduce winter damage to the plant crowns and
minimize temperature fluctuations, which result in plant heaving.
Grazing Maize (Corn)
Grazing Maize is a selectively bred composite designed to graze
by livestock. Grazing Maize can be grazed during late summer months or allowed
to mature and be grazed as standing corn during the winter months. Also, to
prevent corn wastage, daily strip grazing is required. Some source of dry feed
should also be fed to cattle while grazing Maize.
Plant population should be nearly the same as traditional planting
rates and can be planted with a regular corn planter.
Legumes can be interseeded into grass stand by several methods.
The important criterion for success is to achieve good seed-soil contact. If
the seed never makes it into the soil, it is not likely to ever become established.
Different seeding methods are appropriate for different legume species.
Frost seeding works very well for all clovers and lespedeza. Seed-soil
contact is achieved through freezing and thawing action drawing the seed down
into the soil. If there is a heavy thatch layer on the soil surface, the seed
may never actually reach the soil. Frost seeding where cattle have grazed during
the fall or winter and disturbed the thatch is a good strategy. The clovers
tend to be more tolerant of cold temperatures in the seedling stage than is
alfalfa or birdsfoot trefoil, thus making clovers better adapted for frost seeding.
In Illinois the window of opportunity for frost seeding is between February
15 and March 15.
Frost seeding red clover into tall fescue can help improve the
quality of the pasture while also helping to keep it more productive during
the summer months. Ideally a mixture of 30 to 40 percent red clover and the
remainder tall fescues will help decrease the summer slack production of straight
The keys to frost seeding success are to graze the grass down
in the fall. Then frost seed the legume in the spring and next graze back the
early flush of spring grass and then allow for a rest period from grazing to
provide time for the legumes to become established.
EXTENDING THE SUMMER GRAZING SEASON
Cool-season Grass-Legumes Mixtures
Growth of cool-season grasses such as tall fescue, Orchardgrass,
perennial ryegrass, or smooth bromegrass is limited in the summer by both high
temperatures and soil moisture deficiency. Photosynthesis in cool-season plants
becomes much less efficient at higher temperatures. Heavy grazing without rest
also reduces total leaf area available to the plant to support maintenance and
growth. The combined effect of reduced photosynthetic efficiency and diminished
leaf area is low summer pasture production.
Cool-season legumes such as alfalfa and red clover have somewhat
higher optimum growth temperatures than do the cool-season grasses and are frequently
more deeply rooted. For these reasons, cool-season legumes tend to be somewhat
more productive in the summer months. Interseeding legumes into grass dominant
pastures can be the first step toward extending the summer grazing season. Grazing
management, which provides planned rest periods for the pasture plants, is essential
for the maintenance of legumes in pasture.
In a Management Intensive Grazing system, we can also control
grazing pressure to the extent that reproductive stems in the grasses can be
grazed off in the early stages of elongation. This will typically result in
early initiation of tillering and production of more vegetative regrowth during
the summer months. The same management used to accomplish this goal of seedhead
suppression will also encourage legume development in the sward. The combined
effect is greater levels of higher quality cool-season forage in the summer
Warm-season grass species can be used as an alternative to cool-season
pastures in the summer months. Warm-season perennial species would include the
native tall grass prairie species such as big bluestem, eastern gamagrass, indiangrass,
and switchgrass as well as introduced species such as Caucasian bluestem and
The native species are quite sensitive to grazing management and
will respond well to planned rotational grazing. In fact, some recent evidence
has shown that under control grazing systems cool-season and warm-season grasses
can be interseeded and the warm-season grasses will become an important part
of the stand and help increase production during the warm summer months.
Summer annual crops such as sudangrass, sorghum-sudan hybrids,
pearl millet, and crabgrass can also be used to supplement cool-season pastures.
The limiting factor for the use of these crops by many producers is land availability.
While overseeding and no-till establishment can be used successfully for some
warm-season annual species, many respond more favorably to seeding on a tilled
seedbed. Cost of establishment and potential for erosion losses are two main
deterrents to the use of conventionally seeded annual crops.
Because annual crops are typically high investment crops, management
to fully utilize the crop is essential. This is particularly true with the taller
growing species where wastage can be very high if feed budgeting is not tightly
followed. Animal output per acre can frequently be doubled if grazing periods
are kept to fewer than 3 days compared to periods of 14 days or longer.