A couple weeks I was speaking with someone about our farm and they mentioned that driving around the county they mostly see cattle wandering through large fields (aka continuous grazing), rather than being moved daily or every couple of days to new paddocks (aka rotational grazing). It’s true that continuous grazing is the norm, not just in Fauquier County but across the country and probably across the world.
But continuous grazing is not ideal for the soil, the pasture, or the animals. I’ve written before (and I’m sure I will again!) about the benefits of rotational grazing, but I thought it would be interesting to share a bit about what goes into a successful rotational grazing plan. Of course, to know what constitutes success in any realm one has to know what the goals are. The fundamental goals of grazing is to produce delicious, nutrient-rich meat and improving soil health. These two goals are connected – the better the soil, the easier it is to produce great meat.
To achieve the first goal (producing great meat) the cattle need a nutritious and diverse array of plants to graze. The nutritional value of a plant changes over the course of the plant’s growth cycle. The current consensus opinion is that when a plant is just beginning to grow there is little nutritional value available to the cattle. As the plant grows it increases in nutritional value until it produces a seed, at which point the nutritional value of the plant drops of quite sharply. So the key is the have the cattle graze plants that are still growing vigorously (the vegetative state) and have yet to produce a seed. Once a plant does produce a seed, even if the cattle graze it, the plant will not regrow nearly as vigorously as it would if the cattle had grazed it before it seeds out. So a primary consideration when creating a grazing plan is moving the cattle frequently enough to that they can keep a large majority of the plants from seeding out. That ensures that (1) the cattle have as nutritious a diet as possible and (2) the pasture produces as much forage as possible.
This also helps achieve goal number two, which is improving soil health. Improved soil health, to put it very simply, is the result of photosynthesis. Plants exude carbon-rich molecules (often carbohydrates/sugars) out through their roots, which become food for the soil micro-organisms, namely bacteria and fungi. The bacteria and fungi in turn provide plants with many of the nutrients they need to grow. This is called the nutrient cycle. Photosynthetic activity is greatest while plants are growing the most vigorously. So if the cattle are able to keep plants from seeding out while also not grazing them too short, the cattle help maximize photosynthesis and thus maximize the nutrient cycle. And the more the soil is fed through the nutrient cycle, the healthier it becomes.
It’s just as important, or maybe even more so, to not re-graze a plant too soon after the previous grazing. This is called over-grazing.
The challenge of keeping much of the pasture in the vegetative state is increased because plants do not grow at the same rate year-round. Some grow very quickly in the cooler months and slow down considerably in the summer heat. Others do not begin growing much at all until the summer. So timing the rotation from paddock to paddock is dependent on the time of year.
Once the growing season comes to end in the fall and temperatures begin to drop, the plants will largely stop growing. With the change in plant activity comes a change in grazing strategy. In the fall and winter we intended to manage the cattle rotation so that they harvest as much of the available forage as possible. This means smaller paddocks and more frequent moves, even several moves to a new paddock each day. This requires the cattle to be less selective in what they graze. This strategy necessarily means the cattle will move more slowly through the pasture, increasing the density of the manure that they put down on the pasture.
Those are the main considerations of a grazing plan from the plant’s and the animal’s perspectives, but of course we also have to factor in the farmer, too! So a grazing plan needs to take into account the other, non-grazing, day-to-day responsibilities of the farmer and what is feasible without burning out. Successful grazing is the result of good planning, constant observation of the pastures and the animals, and an intuition that only comes with experience and attentiveness (both of which I’m still working on!). Good grazing involves a lot more than just keeping the cattle in one big field year-round.