How to start rotational grazing

After the drought last year, are you looking for a change for your summer pastures? Switching from a continuous grazing system to one that provides a rest period for the plants is one way to help plants recover from drought, while also helping protect plants during future droughts. A rotational grazing system can provide a rest period for plants in paddocks not being grazed.

What exactly is rotational grazing? According to the United States Natural Resource Conservation Service (USNRCS), “Only one portion of the pasture is grazed at a time while the remainder of the pasture ‘rests.’” See Pastures for Profit: A Guide to Rotational Grazing for more from the USNRCS.

To maximize the effects of rotational grazing, animals are moved through the paddocks according to the plants’ growth stages. Credit for this grazing concept goes back to a Society of Range Management meeting in 1950 where Arthur Sampson presented the concept.

Once you’re ready to start a rotational grazing system, it’s time to get a plan!

First, I suggest looking at a Google map or any other aerial photograph you might have of the specific pasture you’re looking at switching over. Take note of existing fencing. If the pasture is just perimeter fenced, how many paddocks are you thinking? Keep in mind more paddocks means more pasture moves. Where are your water sources? Is there any other infrastructure — corrals or building sites — that you need to keep in mind?

Second, you need to figure out how many animals you will be grazing. If you are grazing a 1,400-pound cow with a calf at side the AU will be 1.29. Bulls are also figured into the AU. A 2,000-pound bull will have an AU of 2.0 (numbers used from Beef Cattle Research Council).

Once you have the total AU for the herd you want to rotational graze, you can now estimate the carrying capacity for your pasture. These can either be figured by month, or for the grazing season. If you don’t know the carrying capacity for the species on your pastures, the Beef Cattle Research Council has a calculator at its website.

Next, determine the number of paddocks in a pasture. The number of paddocks in a rotation can range from two all the way up to 40 or more!

There is no “best” number. Even if you take a pasture, divide it in half and have two paddocks — you’re still resting half the pasture. Existing fences, topography and water sources often play a role in where paddocks are.

The USNRCS has a simple equation for determining the number of paddocks needed. They take the rest period required for the plants in the pasture and divide it by the grazing period you would like to use in each pasture. Then add the number of animal groups that will graze in those paddocks. On our farm, we have been practicing rotational grazing for over 20 years. Our average rest period is 45 days and we move paddocks approximately every seven days (this number is very dependent on the growing season). So for us (45/7) + 1 = 7.42. We have seven paddocks in our pasture.

When you’re designing the paddocks on the map for your rotational grazing, keep in mind where your current water sources are or where potential water sources can be. If you’re wanting to keep inputs low, try to work with existing water sources. One way of servicing multiple paddocks with one water source is by designing a laneway or a water pen. This way, multiple paddocks can use one source. The only downfall of this is these areas often become “sacrifice areas” or areas of higher use and don’t get the rest the paddocks do.

Once you have mapped (and ground-truthed) where you want your paddocks to go, next is planning fencing. There are many options for fencing these days from using permanent to temporary; running four-strand barbed-wire fences or using electric poly-wire. The choice is entirely up to you. Permanent fences have more appeal for people who have static cattle numbers and have a bit of experience with rotational grazing. One thing to keep in mind when planning fencing is how many paddocks you’re planning on moving through. If you start with a few, large paddocks, there’s always room to make them smaller and have more frequent moves. If this is an option for you, you might want to make the larger pad- docks with more permanent fencing, then add temporary fencing as time goes on. Temporary fencing allows you to alter paddocks and make changes as needed. The USNRCS says, “Don’t let your current fencing arrangement limit you. Fence in a way that makes the best use of your land.”

The paddocks are fenced and the cattle are turned out — now what? From when to make your next move, or seeing if a paddock has had enough rest, monitoring is a constant. While you can use general guidelines, having an eye on the ground is best. And since everyone has a phone in their pocket, it’s easy to take dated photos and compare not only from month to month, but year to year. Some tips on what to monitor include: grazing and rest periods, which pasture you grazed first and last, areas where animals congregate, and stubble height and regrowth rate.

There are many recommendations when it comes to rotational grazing. However, I find the best thing about it is you can make it to fit you and your farm! If you know of another producer who already rotational grazes, ask them for tips and advice. Even though I’ve been practicing rotational grazing for almost 20 years, I learn something new about our pastures every year. Hopefully, with this advice, you will be able to rotational graze and have productive pastures for years to come.

– Jill Burkhardt, her husband Kelly, and their three children, own and operate a mixed farm near Gwynne, Alta. Originally hailing from Montana, she has a range management degree from Montana State University.