Page 14—Foraging Around, Lancaster Farming, Saturday, July 15, 2000
Duane E. Pysher
Grassland Management Specialist
Natural Resources
Conservation Service
Harrisburg
Recently, I conducted a discus
sion on horse pasture management
with a group of graziers
As part of the dis
cussion, I explained
why it is important
to provide a rest
period for the
forages. I empha
sized that in a con
tinuous grazed
pasture, there is no
rest period; how
ever, if you split a
pasture in two, then
each paddock is
rested 50 percent of
the time.
If you split a pas
ture into 16 pad
docks, each paddock
is rested 94 percent
of the time.
I had just finished
this discussion when
one of the partici
pants offered this
comment: “If I split
my pastures in half,
my horses would
ruin my pastures
twice as fast.”
It quickly became
apparent to me that
grazing control con
cepts are not as
easily understood as
perhaps I though
they were.
I will devote this
column to explain
ing some of the basic
concepts of grazing
management and
control.
First, let’s define
some of the termi
nology. The term
“rest period,” refers
to the amount of
time a specific land
area is allowed to
regrow before ani
mals are allowed to
regraze it. “Grazing
period” is the length
of time that grazing
livestock occupy a
specific land area. A
“grazing cycle” is
the total time be
tween the beginning
of one grazing
period to the begin
ning of another or,
in simple terms, the
grazing period plus
the rest period.
The “specific land
area” referred to
above denotes a pas
ture, a paddock, or
whatever subdivi
sion of land that the
animals have access
to at that point in
time.
There are three basic ways to con
trol grazing management of forages.
The first control is by changing the
number of livestock that will graze a
piece of land, commonly called
“stocking density.” The second con
trol is applied when we have a set
number of animals and we change
the size of the piece of land we allow
them to graze. The third control is
that of time; when we have a set
number of animals and a set size of
land for them to graze, we alter the
time they have access to graze. The
three controls are the numbers of
livestock, the size of grazing unit,
and the time to graze. Most grazing
systems use time and size to control
their grazing because most produc
ers do not have the ability to easily
change herd numbers.
Generally, a paddock should be
grazed for no more than three days.
The reason for this is that by day
four, regrowth is occurring. This re
growth is very palatable and the
livestock usually seek them out for
this reason. Overgrazing then be
comes a problem and often causes a
stand to be destroyed.
The shorter the grazing period,
the better utilization of the forage.
The reason for that is that the longer
the livestock are in a paddock, the
more fouling and treading that will
occur. There will also be much less
selective grazing occurring when the
grazing period is short. The live
stock generally eat the highest qual
ity forage first and eat the less
desirable stuff second. They also
tend to eat more when introduced to
fresh forage, so there are animal
performance reasons to move live
stock to new paddocks in addition
to maintaining forage quality.
A quick and easy way to deter
mine if your system is operating
properly is to simply walk a pad
dock from which you just removed
the livestock and observe what has
occurred. If there is a lot of unhar
vested forage, you may need to
reduce the size of the paddocks. If
the stubble height left is too low for
(Turn to Pago 15)