Putting the Pieces Together: A Scientific Approach to Grazing Education.

Developing critical thinking skills is a key component of education, whether one is teaching students or providing continuing education to agricultural producers and advisors. This is especially true in grazing education, because grazing systems are complex and dynamic. Since grazing systems have many interdependent components, educators need to place as much emphasis on the interdependency of the components as they do on the components themselves. Doing this requires two basic steps. First, one should clearly introduce and discuss management and growing condition effects on the forage growth curve. This can be demonstrated conceptually at first. Then, scientific literature can provide specific examples of how the growth curve of forage species compare, the relationship between forage quality and the growth curve of different species, and how leaf area development influences light interception and net photosynthesis. In this discussion, it should be recognized that the goal of optimal grazing management is to manipulate and exploit the growth curve of the pasture species (including both above and below ground biomass). Building upon this foundational concept of forage growth patterns, the second step should be to introduce the calculations for determining the number and size of paddocks. Using those two equations together, one can use a calculator or spreadsheet to examine a change or, more appropriately, changes (since changing one aspect of the system will likely alter many other aspects). This mathematical construct can be further expanded to look at additional issues. For example, the influence of grazing time, bite rate, and bite size on dry matter intake rate can be plugged into an expanded version of the model. Using this approach will provide an outline for the student, farmer, or advisor to critique new or alternative grazing systems.