Simplifying Rotational Grazing
Published on Tue, 02/06/2018 - 2:31pm
Simplifying Rotational Grazing
By Michael Cox for American Cattlemen
Management intensive grazing, controlled grazing, buffer grazing, deferred grazing, creep grazing; the list is endless. For many ranchers, trying to get to grips with the many forms of rotational grazing can leave us in a tailspin. Perhaps it’s no wonder that the 2012 Census of Agriculture found that only 30% of producers used rotational grazing, with most using extensive rather than intensive grazing.
Rotational grazing does not need to be a complicated process. The tried and trusted method of rotationally grazing paddocks, developed by the original pioneers and master graziers of New Zealand and Ireland, is based on a few simple principles listed below. A basic understanding of these key principles is all that is required to begin rotationally grazing and improving the profitability of your ranch.
• Stocking rate: Under the New Zealand/Irish system, the stocking rate of the farm is set so that herd demand equals the average daily growth of the farm over the year. For example, if the average growth per acre is 30lbs Dry Matter, then the farm could be stocked at 1 cow to the acre. As a result of having enough animals to eat the average daily growth rate, surpluses and deficits will naturally occur during high and low growth months. Surpluses can be removed from the pastures as bales and fed back during deficit periods when grass growth is low. The desired stocking rate can change if warm season or cool season crops are grown. For beginners, it can be useful to start rotationally grazing a large group of animals on your best pastures, especially irrigated pastures. The stocking rate can be adjusted as necessary on this area of your ranch by moving cows on or off to the other land area of the ranch.
• Measurement: ‘You can’t manage what you don’t measure,’ is a saying that is certainly true for rotational grazing. A weekly ‘grass walk’, where the amount of pasture dry matter available in each paddock is measured and recorded is crucial to making informed grazing decisions. Measurement can be carried out using a variety of tools. A Pasture Stick is the simplest method of measuring grass. Plate meters or using the ‘cut-and-weigh’ method are also straightforward tasks that will offer more accuracy for estimating dry matter availability. Once all the paddock measurements have been recorded, it is hugely beneficial to enter the data into a ‘grass wedge’. A grass wedge is a visual tool which ranks paddocks in order from high to low based on the amount of forage available in the paddock. A simple grass wedge computer system is available from the University of Missouri Extension website. Agrinet.ie is an online grass wedge system used by Irish and New Zealand grazing farmers. The wedge allows farmers to see how much grass is on the farm, what the growth rate was for the previous week, what the herd demand for forage is, and whether there is a grass surplus or deficit on the farm.
• Rotation Length: The length of the rotation from paddock to paddock across the farm area will change during the season based on growth rates. When grass is growing fast, it will be necessary to ‘skip’ long grass paddocks and keep consistent quality forage in-front of the herd. The long grass paddocks can be baled as surplus forage. When grass growth slows down in the Fall, the rotation length will increase greatly, and hay or other supplement will be needed to fill the feed deficit. Rotation length also allows a rest period for grasses to recover and regrow to the optimum stage before the next grazing event.
• Infrastructure: Grazing infrastructure can be off-putting to rotational grazing newcomers, but the key is to keep the system as simple as possible. For ranchers starting out in rotational grazing, they should utilize their existing infrastructure as best they can. For example, temporary fences can be set up around watering facilities and drinkers, around shade and windbreak areas etc. Using temporary polywire fences for the first few years can help ranchers plan where they would like to place permanent paddock fencing in the future. At a minimum, there should be 8 paddocks used in the rotation, but the more drinkers and paddocks available, the better. Ideally a lane or farm road running through the farm will allow easy access in and out of paddocks. Again, this can be easily set up using some polywire and pegs.
• Mobs: Having a small number of similar-class animals in a group or mob will help simplify the system. A few large mobs is far easier to manage than several small mobs scattered across the farm.
The benefits of rotational grazing are too large to ignore. Research from South Dakota State University says it simply as; ‘Rotational grazing increases long-term profit and improves soil conditions.’ Some of the other main benefits include;
Improved pasture quality; Pastures have rest periods to recover under rotational grazing, which offers high quality plants adequate time to recover between grazings. In continuous grazing situations, cows will continually eat the most palatable grasses, which will eventually lead to selective overgrazing and a reduction in high quality grasses in the sward.
Improved total forage growth; Rest periods allow grasses to recover properly in comparison to continuously grazed pasture. ‘Grass-grows-grass’ – a common phrase among graziers, implies that rested grass has a larger leaf surface area for photosynthesis, and therefore will grow more leaf area, which in turn will grow even more leaf area. By moving cows from paddock to paddock, the rotation will protect re-growing pastures from overgrazing and increase the overall forage available over time.
Increased Stocking Rate; The above benefits will allow more stock to be carried per acre. Stocking rate has a direct effect on Net Profit, however increased stocking rate is most profitable when the additional animals are fed home-grown forage, rather than purchased feed.
Better Animal Performance; By grazing rotationally, animals are offered high-quality forage regularly. For Moma cows being allocated fresh pasture every 24 hours, it is similar to a daily trip to the candy store! A fresh grass allocation daily or every few days will supply animals with energy dense grass at the top of the plant, resulting in better liveweight gain and overall performance. Pinkeye issues can be reduced if vegetation is maintained at the leaf stage and seed heading-out is delayed or reduced as much as possible. Fly problems and worm burden for young calves will also be reduced, as the majority of flies and worms will have died or be in the incorrect stage of their life cycle to infect stock when the herd returns to the paddock after a number of weeks.
As ranchers, we are price-takers of a commodity product. The only market factors under our direct control is the cost of production inside the ranch fence-line. Rotational grazing is a proven method of lifting animal and farm output, while lowering cost of production. Home-grown feed is our cheapest feedsource available and rotationally grazing pastures will improve the quantity and quality of this feed. Life can sometimes be as simple as we make it, rotational grazing is no different.