Good Grazing Practices with Sarah Flack

Nationally-known grazing consultant Sarah Flack shares her childhood experiences with farming and how they’ve helped shape her ideas about good grazing practices.

Sarah Flack with cow

Sarah Flack’s lifelong experience with grazing began on the family farm as they transformed brushy fields into high-quality pasture.

Photo courtesy Sarah Flack

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Sarah Flack’s The Art and Science of Grazing (Chelsea Green Publishing, 2016) is a comprehensive guide to grazing management for ruminant farmers. Flack’s principles help farmers design and manage successful grazing systems that meet the needs of their livestock, pasture plants, soils and the larger ecosystem. In the following interview, Flack shares her history of growing up on a farm, how that has influenced her ideas about grazing practices, and offers a glimpse at what farmers can find within the pages of her new book.

You grew up on farms, and in the book, you give two vivid examples of childhood experiences that taught you the power of both good grazing management and bad grazing management. What were those experiences, and what is it you learned from them?

SF:  When I was a child my family lived on the South Island of New Zealand for a number of years.  Since both my parents were scientists interested in farming, we spent a lot of time visiting farms and talking about ecology, plants, and soils.  Once, during a night of heavy rain, a landslide happened. A big area of the neighbors’ overgrazed sheep pasture slid down the hill and hit the back of our home. I got a vividly memorable lesson in what bad grazing practices can do!  We were lucky that we all were safe and the house wasn’t too badly damaged.  We had lively family conversations over meals for the next few weeks about how different types of grazing practices can either help, or damage, plants and their roots.

When we moved back to the United States to the farm in northern Vermont, I got hands-on experience as my parents used high stock-density grazing (it was called mob stocking back then) to improve overgrown, poor-quality pasture.  Watching the poor-quality pastures on our family farm transform into high-quality, highly productive pastures through the use of good grazing practices got me even more interested in the beneficial role herbivores can play in our ecosystem.

The book is called The Art and Science of Grazing. Are the art and the science two separate things, or do farmers need to study and practice both? Which one is more important?

SF:  In the book, each chapter explains (in farmer-friendly and easy-to-read language) part of the science that addresses what pasture plants, soils, and livestock need in order to thrive.  But I didn’t want the book to be all science, all theory. I knew it would be important to include real, practical examples of how farmers are using and applying that science on their own farms.  So I wrote real-life farm profiles (one for almost every chapter in the book) that describe how farmers creatively apply the principles of good grazing to their own farms.  Really, both are important!  We need to know the science behind what we are doing, but then we need to find the most practical and creative way—the art, if you will—to apply that science on each farm.

The introduction to the book is titled Transforming the Landscape Through Grazing. That’s a big idea—that you can change a landscape simply by having animals graze. In broad terms, how does such a transformation happen?

SF:  It is incredible to watch how well-managed grazing with a herd or flock can totally change the plant species composition, improve soil health, and increase both the productivity and quality of the forage in a pasture.  When livestock are managed correctly, they remain in any portion of a pasture for only a relatively short period of time. Then they will be moved to a new part of the pasture, and the grazed area will be allowed enough time to fully regrow before being grazed again.  This relatively simple process of short periods of occupation when plants are partially defoliated, followed by long rest or regrowth periods allows the more productive “grazing-adapted” pasture grasses and legumes to thrive, while the weed species that are less tolerant of this type of management will die out.  Two of the fundamental guidelines of good grazing are:  1) short periods of occupation and 2) variable regrowth periods.  Following these guidelines allows you to use livestock to change the plant species in a pasture in a truly transformative way. 

You tell farmers to first study their pastures from the plants’ perspective, and then from the animals’ perspective. That seems backwards—aren’t the animals the more important component? After all, they’re the source of a farm’s revenue—from sales of milk, meat, wool, breeding stock, etc.

SF:  Both are important, but farmers who are raising ruminants on pasture are grass farmers.  We have to manage the pasture plants so they can in turn support the nutritional needs of the pasture.  Take care of the plants (and soils), and those plants will then feed our cows, sheep and goats.  Care and understanding of the animals needs is also essential, but as grass farmers, we start with the pasture soils and plants needs and then our livestock will be able to convert those plants into meat, milk and fiber. 

Grass farming is pretty awesome. Think about it:  We are capturing sunlight in green plants through photosynthesis and taking carbon out of the air in that process.  Then our ruminant livestock eat the plants, and they can digest the plant fibers that mono-gastric animals (humans, pigs, chickens) are not able to digest.  So ruminants can turn sunlight into milk, meat, and fiber.  As grass farmers, we need to manage each step of that conversion, starting with the plants.

 Vermont, your home state, is a moist climate. How does your experience farming and studying in a humid environment influence how you teach grazing management? Can readers from all regions of North America benefit from the information and management strategies you present in the book?

SF:  The information in my book is relevant to pastures in areas that get a reasonably well-balanced, moderate amount of rainfall (mesic ecosystems) and to farms where the pastures are irrigated.  So this does cover much of the United States and a range of climates.  What I don’t discuss in this book are the types of plants or rangeland grazing management systems found in dryland areas (brittle ecosystems) or range pastures where there is infrequent rainfall.  There are some other great books and very knowledgeable consultants who offer excellent information on dryland or range grazing systems. 

One concept you write about in the book is “paddock power.” Sounds like a new graphic novel. What is “paddock power?”

SF: I have thought about writing a fun comic book style instructional manual about this for farmers!  Paddock power is a simple way to approach improving an underperforming pasture system. More paddocks = more power to control the stocking density and the nutritional quality of what the animals are eating in the pasture. We can gradually subdivide the existing pasture into smaller and smaller paddocks.  As the number of paddocks increase, we are able to give more of the pasture plants more time to rest and regrow.  Gradual is a key point here—there’s no need to rush into setting up 90 paddocks in a day!

For farmers who have been feeding their animals primarily on purchased grains and hay, how can they make a shift to feeding grass? What’s the starting point, and how long does the transition take?

SF:  Each farm wanting to transition from a confinement- or grain-feeding system to a higher forage or all-forage system will need to do so at their own pace.  Farms currently feeding a ration that includes a lot of grain may be able to quickly add a small amount of pasture to the ration.  But that same farm would need to take much longer to transition the herd in order to replace most or all of the grain with pasture.   In my consulting work, sometimes a farmer and I have been able to spend a few months planning and setting up fencing, and then the farmer made the transition in just a few weeks.  However, other farms have taken a couple of years to gradually transition, making the change for different groups of animals at different speeds.   It is often easiest to start with just one group of animals on the farm.  For example, on a dairy farm, learning how to set up a grazing system for the heifers or dry cows is a good place to start.  Then later the farmer can develop a pasture-based feeding system for the milking herd and gradually make that transition.

Who were your best teachers, and how did their work and philosophy influence your consulting and teaching style?

SF:  I have had so many amazing mentors and teachers in my life; it’s hard to single out specific influences.  My parents were my first teachers, and they both encouraged my natural curiosity about the world around me and taught me to ask questions, to observe and learn how things are interconnected.  Over the years, I have had the honor to work with many farmers who have both taught me and learned with me about farming.  In the process of working with them, I realized that each farmer has a different learning style.  So over time, my approach to consulting has become more flexible and creative (and hopefully fun!) as I try to help each farmer learn information and find practical ways to apply it.

In the book, you write about actual farms—11 of them—and discuss their management choices. How did you choose these farms, and why did you decide to include these profiles in the book?

SF:  I wanted to include examples of many types and sizes of farms.  The farms I wrote about include a 3-cow “micro” dairy grazing system, a couple of grazing systems for 300 to 400 dairy cows, several beef farms (ranging in size from 30 to over 500 animals), a goat dairy that uses browse as well as pasture, and a sheep dairy.  I also sought to include farms in a range of climates: there are examples of farms where fescue and Johnsongrass are grazed as well as farms in colder climates that graze only cool-season perennial grasses and legumes.  Some of the example farms graze only perennials, while others creatively use annual crops for grazing, too. My goal was to describe how different farmers were able to creatively apply the basic principles of good grazing management, and then explain how that has resulted in long-term success for each farm.

The recordkeeping involved with grass farming and high stock-density grazing seems a little intimidating. What advice do you offer farmers to help make record-keeping productive and manageable?

SF:  The record keeping system doesn’t have to be intimidating.  The first thing to figure out is to what extent of records a farmer is realistically likely to keep, and what will motivate the farmer to continue to keep the records.  Then we also look at what records are required by the farm’s organic certifier or by local water-quality regulations.  Based on those preferences and needs, we seek out a system that will provide genuinely useful information for the farm and farmer, because useful records are more likely to be kept up with then a record keeping system that is redundant or full of irrelevant information.

You make it clear that working with electric fence systems is almost a requirement when setting up a good grazing system. What advice do you offer to farmers who haven’t had much experience with electric fence? Are there common mistakes you’d like to warn farmers about, or a couple of your best pointers for working efficiently with electric fence?

SF:  The development of electric fence technology made it easier for farmers to use less labor while managing pastures with variable stocking densities, occupation periods, and regrowth periods.  Electric fence, when installed correctly, gives us tremendous flexibility, especially a combination of permanent and portable fencing.  However, in order to be effective at keeping livestock in bounds, it’s crucial to size the energizer correctly for the amount of fence in use. Make sure your grounding system is large enough, too.  Inadequately grounded energizers are the most common fencing mistake that I see when visiting farms.  Luckily it is a problem we can find and fix quickly!

There are also many “tricks” of fence planning and construction, and the best way to learn those is from someone who has experience.  Many high-tensile fence dealers offer free spring fence-building clinics, or you can hire them to come spend part of a day on your farm teaching you how to build fences that work well, last a long time, and will improve your quality of life as a farmer by keeping the livestock where you want them.


Reprinted with permission from Chelsea Green Publishing, in conjunction with the publication of The Art and Science of Grazing by Sarah Flack, 2016. Images courtesy Sarah Flack and Chelsea Green Publishing.