Creative Application of Grazing Science
By Sarah Flack, Grass-based and organic dairy livestock
production consultant, Sarah Flack Consulting
Added April 29, 2016. In the last few years, while working on writing a book, I’ve had the opportunity to visit many successful organic dairy farms and learn more about how farmers in different climates have successfully designed and managed their pastures. I visited farms providing all or most of the herds dry matter from pasture during the grazing season, as well as farms on more limited land bases where grazing only provides 40 to 50% of the herd’s intake needs. Some used only perennial plants, while others used innovative mixtures of both annuals and perennials. The successful grazing systems were each unique and creatively designed to meet the farm and farm family goals.
In the process of visiting all these farms, I was reminded that all successful pasture systems are based on some basic and essential guidelines. These guidelines aren’t new, they’ve been known for at least 200 years, and during that time farmers and researchers have used them to develop different types of grazing methods, and given those grazing systems and methods a bunch of different names.
Regardless of the name of the grazing system, the successful ones use relatively short periods of occupation so the dairy cows aren’t left in the same paddock for too many days. They also provide enough time to let the plants fully re-grow after each grazing (variable recovery periods). By studying grazing systems currently in use which are working well on a variety of farms, we can learn more about these grazing principals and how to apply them so that we are caring for the pasture plants, livestock, soils, farmers and our ecosystem. Along the way, we can be better informed and inspired by the many creative ways that these basic grazing guidelines are in use on different farms.
Grazing adapted plants, and our organic dairy cows, each have requirements, which complement each other synergistically. Plants respond best to short periods of grazing followed by long regrowth periods. Livestock do best in pastures that are managed so each paddock is grazed quickly and which are full of high-quality forage, given sufficient time to regrow. Good grazing management is a win–win system for plants and livestock. It is also good for our soils and the larger ecosystem we all live in and share. Good management supports the development of healthier soils, sequesters carbon, and prevents erosion.
As we manage the plants according to their needs, we encourage the growth of the more desirable, productive and palatable pasture species. Good management also increases pasture plant density. As plant density increases, there is more green leaf area photosynthesizing so more sunlight is utilized. This in turn produces even more forage, and allows the livestock to more easily maximize dry matter intake from pasture because they are able to get more forage in each bite. Additional results of this good management are that we are also protecting soils with more vegetative cover and healthier plant root development.
As climate change brings us more unpredictable weather events, particularly high rainfall events and extended dry periods, it is essential that our pastures be full of healthy plants with well-developed root systems growing in healthy soils. These well-managed pastures will produce better in a drought because the soils will be healthier, and plants will have more extensive roots. These healthy pastures will also absorb the rainfall from those 5-inch extreme rain events, instead of letting it runoff. There are so many benefits from managing our pastures better, including improved ecosystem resiliency, higher quality and quantity of forage, more sustainable farm income, improved animal welfare, human health benefits from grass fed products, protection of our precious soils, and decreased use of harmful agricultural chemicals.
In order to be able to do this good grazing management, we need to know what the basic essential guidelines of how to care for grazing adapted pasture plants are. But grazing isn’t just about plants and soils, so we also need to know how to practice good animal husbandry of our grass fed livestock. The deeper our understanding of the basic guidelines of good grazing management and animal husbandry, the easier it will be for us to design practical grazing systems which can succeed in the long run.
Farms following the essential guidelines in grazing management are able to prevent overgrazing damage to plants by letting the plants regrow sufficiently after each grazing, and not leaving them in each paddock for too long. Regrowth periods are varied depending on how fast the pasture plants are growing to assure that plants have always had enough time to regrow before being grazed. In addition, animals are moved out of the paddock before they either graze the pastures down too short, or are able to re-graze plants that have started to regrow again.
Some of the “tools” of grazing which we can use include the stocking rate (number of animals on the whole farm), stocking density (number of animals at a specific time in an individual paddock), hoof impact/trampling effect, choice of what pre grazing height to graze at, and how short to graze it (post grazing residual).
In the last few years I visited many well-designed and successful grazing systems on dairy, beef, sheep and goat farms and have seen creative ideas on how these “good grazing guidelines” and the “graziers tools” are being applied. Each of these farms is grazing on different types of soils, in different climates, using different types of pasture plants, so they have each had to adjust their management accordingly. Farms are using higher or lower stocking densities depending on the nutritional needs of the livestock, the time of the year, soil conditions, and types of plant species. Some farms have moved to a taller or shorter pre-grazing height, but the good managers also vary this based on what growth phase the plants are in and the class of livestock they are grazing. These good graziers I visited also clearly see stock density, pre-grazing height and post-grazing residual as “tools”, and don’t approach them dogmatically. This allows them to make what may seem like subtle changes in how cattle are rotated through the farm, which result in very noticeable improvements in pasture quality and livestock performance. To really be able to see good managers using these tools successfully and creatively, you need to visit the same farm several times during the grazing season. Then you will see how an understanding of these tools allows them to use them much more successfully than a simple dogmatic decision to pick a specific “ideal” pre-grazing height, stocking density or post-grazing residual height. When you ask these skilled graziers what their ideal stocking density or pre-grazing height is, they will probably tell you “it depends”, and they are right about that!
The proof is in the results which, as predicted by Andre Voisin in the 1950s, shows us that farmers practicing good grazing management have pastures which can improve steadily and continuously over many decades. In the last few years, I have visited farms using good grazing management systems to create impressive short-term improvements in pasture quality and productivity. But I have also visited farms where, after several decades of good grazing management, there is still improvement in the health and productivity of their pastures.
Andre Voisin, author of Grass Productivity (Conservation Classics) 1959, used the term rational to describe good grazing systems. Rational thinking can be helpful in planning and managing grazing. Rational grazing can also refer to the importance of “rationing” out the pasture instead of releasing the herd into the whole area. Voisin’s book is full of technical information, but also shares his obvious passion for the subject, which he expresses here, along with a good description of what a well-managed pasture landscape should look like:
“What loveliness! What shades of colour all blending to form an even more magnificent picture where rational grazing is applied. The different paddocks, at different stages of regrowth, are not all of the same hue. Moreover, in a well-managed system the paddocks are not grazed in the same order as they stand, and so the colour tones, like reflections on the sea, do not gradually and uniformly diminish in intensity. Between two dark greens one glimpses a paddock lighter in colour, like the depth of a wave. A part where the grass has already begun to flower takes on an undulating, wavy aspect. What enchantment a pasture grazed in this way offers they eye!” Grass Productivity, by Andre Voisin (Conservation Classics), 1959.
Sarah Flack is a consultant specializing in grass-based and organic livestock production. She is the author of Organic Dairy Production, co-author of The Organic Dairy Handbook and her new book The Art & Science of Grazing will be available from Chelsea Green Publishing in the spring.
Contact Sarah at www.sarahflackconsulting.com