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Volume 6 No.4 Fall 2002
Editor: Laurie Ball-Gisch
Intensive Grazing: Experiences and tips from our resident experts
Susan Mongold wrote:
When I was figuring out intensive grazing for the cattle that we used to raise, we would
figure a cow and her calf as a unit during the growing season. If you want to stock pile
grass so as to graze into the fall winter and spring then you need enough so that you have
extra grass at the end of the season and plan for this.
So it would be the same for sheep. The rule of thumb is that you can graze 5 to 7 sheep
and their lambs on the same amount of pasture that it takes to support one cow. Using
intensive grazing you can get far more from your grass in a normal rainfall year.
With the cows we were using 1 to 3 breaks a day and grazing them at an intensity of 24
to 56 cows per acre!!! If you figure out the sheep equivalent using 6 sheep and their
lambs that would be 144 to 336 sheep and their lambs per acre. At that rate the
sheep are not fussy eaters but gobble every blade of grass and weeds. In the spring the
cows were moved twice a day but later on when the calves started to eat we moved the herd
3 times a day. This was done because the calves would only eat for an hour and then lay
down. The cows would continue to eat and when the calves would get up to eat again
there would be only poor quality grass left. Moving the fence 3 times a day gave the
calves three lush grass meals and higher gains. You can also do this by making a
creep for the calves and let then graze the next break ahead so they always have access to
fresh lush grass. The other reason for giving more breaks a day is to minimize
bloat. With a large amount of cows or sheep on a very small amount of pasture no one sheep
can get enough of the very lush clover or alfalfa to cause them to bloat. Moving the
break several times a day gives them fresh feed and the highest nutrition possible while
minimizing the risks.
Doing this we were getting 409 lbs of gain on each calf plus maybe 100 lbs or more gain
on the cows for each acre. That is a gain of about 2 lbs of gain a day for each calf.
At these stocking rates your management has to be intensive too. Our pastures are
irrigated so we can control the grass growth more easily. With pastures that are not
irrigated you have to be aware of exactly how much grass you have at all times in reserve
and how long it will take to grow more. Every 3 to 4 days each pasture was rated as to how
high the grass growth was and the quality of that grass and then I could figure out just
how many grazing days I had left for the herd. If the grass is getting ahead of you, then
skip a pasture and hay that one and jump the sheep up to one that is in the perfect
grazing stage of about 6 inches of leaf. This happens in the spring. The excess grass is
used for hay by most graziers.
When you intensive graze at this rate the animals eat everything and it looks like a
mowed golf course. The grass that grows back is all leaf and no stem. The grazed area has
at least 30 days to regrow and sometimes it needs 60 days to regrow. However
drought, heat and cooler days all affect the grasses growth and has to be figured in. This
is where taking a grass inventory helps. I believe that I figured that in inch of leaf
(don’t count the stems is about 1000 lbs of feed). If your grass is slowing in growth
and your next pasture is not quite ready you start slowing them down by keeping them
in a break a bit extra longer.
Since every pasture and region is different you will have to get the stocking rate for
the average pasture in your area and use this to do your initial figuring. You will get
better with practice.
In most average rainfall areas it takes about 2 to 2 1/2 acres to support a cow and her
calf for a year. So that means that that same pasture will support say 6 sheep and their
lambs for a year. Intensive grazing can allow you to increase the stocking rate, sometimes
double. We ran almost 200 cows on about 100 irrigated acres but only for the growing
season from mid April through September. The cows were taken off the farm in October.
Barbara Webb wrote:
To weigh in on sheep/acre, specifically regarding weeds - it is my experience that by
grossly overstocking a weedy pasture, the sheep will be forced to eat the weeds, which
they may or may not do otherwise, even the less palatable weeds. Thankfully,
Icelandics love to eat just about anything, but by making smaller paddocks in the
beginning, a.) weeds are heavily chewed down which most cannot tolerate for long,
and b.) if the green stuff is chewed right down, all that sunlight reaching the soil
will encourage the pasture plants to fill in. I have had very good results
letting them graze the clumping grasses right down, as native white clover then fills in
beautifully in the empty spaces, no seeding required.
A good model is the huge herds of Bison that would range the west. Huge numbers
of animals traveling together, their stocking rate per acre would be very high.
Important though is an adequate resting period. I would worry about the
rest time more than the stocking rate. Also, if overstocking, keep the time in
the field very short. Then they can't actually eat down to the dirt, which can
stunt the plants and damage their teeth. I have also read that by grazing closely to
the ground, parasite eggs are subjected to sunlight, which can kill some/most of them.
I run about 250 sheep, adults and lambs, on about 25 acres of pasture, maybe 28.
I also move them either daily, or at most, every 2 or 3 days. The pastures have been
improving steadily since we came, both in density and in desirable plant species.
I've read that it is better to keep up an aggressive rotation schedule, even if it
means occasionally removing them from the fields onto dry lot hay for a few days to
fill in gaps between fields. A few days of hay in the grand scheme is much
less costly, both monetarily and in terms of the pasture conditions, than rotating into a
field that is not ready. I find that the doldrums of August when it is likely that
the pasture will run low, is also a good time to bring the ewes in for weaning anyway.
Susan Mongold wrote:
The tighter you run the sheep and the more often you change them the less selective they
become. Same for cows. But as Barbara says the trick is to give the pasture adequate rest
and NEVER come back on that grass until it has grown again to it’s ideal state of 5
to 7 inches no matter whether it takes 3 weeks or 8 weeks or 2 years as in the
prairie dryland. To graze before this point will stress the grass and cause your pasture
to become damaged and much less productive or even die or winterkill. The other
point to remember is to stay on one break for no more than 3 days. One day or less is
best. If the break is too big the sheep will, as Ann says eat the ice cream and leave the
cardboard and you will be left with big clumps of grass and weeds that will grow too
coarse and lignified for anything to eat them. At this point you can mow or grow this
pasture for a hay field and get rid of it that way.
I have noticed however that our sheep will clean up this wolfy stuff in the early
spring when the new grass is washy and they need some fiber to balance their
digestion systems. Stuff that they wouldn’t touch disappears in the spring.
In figuring the animal units a calf after being weaned is considered * a unit and as a
yearling is * of a cow unit and remains this till she calves at which time she starts
eating more and she and her calf is 1 cow unit. So a sheep would be 1/6th of this amount
for figuring pasture usage.
These are rough ways to figure out pasture usage, as there are many variables
including the weather, season, rainfall etc.
When you are just beginning to graze intensively, it is a good exercise to measure off
a 10 foot square with stakes and string in a pasture when the forage is lush and green and
about 5 to 7 inches high and hand clip all of the grass/ clover weeds on that plot.
Don’t include any stems or dried stuff, just the succulent forage. Dry this on a tarp
till it is as dry as hay and then weigh it.
Then you can figure out how many 10’ X10’ squares there are in the field that
you have, roughly. Multiply this number by the weight of the dried forage that you clipped
and you will get a pretty good of how much pounds of forage per acre you are looking at
when your pasture is 5 to 7 inches high.
My sheep eat 7 to 10 lbs of hay a day in the winter and they will eat about that
equivalent of grass in the growing season. So if your 10’ X 10’ yielded a pound
of dried grass then it will take about 10 of those 10’ X10’ patches to feed your
sheep for one day. Measure this off and eyeball it. This way you can start to get a feel
of how large to make your breaks.
The sheep will also tell you if the break is too small or when it is time to move to a
new break. They will utilize the forage better and complain less if they are moved
frequently to small just right sized breaks. Practice will tell you what that size is and
the size will change from pasture to pasture and from season to season. If one pasture has
scant vegetation then you will need a bigger break for them or move it faster.
In the spring and late fall the grass will be tender and will not stay in their
digestive systems very long so they can eat more so the breaks need to be small to prevent
trampling and moved very frequently, at least once a day. In summer the grass lignifies
even if it is green and lush and takes more time to go through the digestive system which
means that the sheep can stay in the breaks longer as they will not trample the grass as
much and it will take less grass to fill them up. It is interesting and a real workout for
your brain. The Holistic Resource Management workbook helps you learn to track these
things on a worksheet that you can buy from them. We found it very helpful to put this all
down so you can see it all visually. These sheets are invaluable for reference also and we
are always going back to them as a reference.
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