Thinking of ranchers as “grass farmers” is a useful starting point, but it’s even more accurate to think of them as Net Energy farmers. Here’s why.

Most people measure grass or forage by weight or by the acre, but not all grass or forage is created equal. An acre of irrigated clover is not equal to an acre of dryland sagebrush, nor is  one ton of alfalfa hay equal to one ton of rice straw. Any rancher can appreciate that the value of these feedstuffs to grazing animals varies dramatically. How should the value of the grass resource be measured? What makes forage useful and valuable to grazing animals? 

The answers lie in animal nutrition. Animals live and grow by having their nutritional needs met, and the most critical nutrient provided by forage is energy. Therefore, the most meaningful way to measure the value of a forage is by the energy it supplies to grazing animals.

Not all energy in a feedstuff is available to the animal. Some is indigestible or lost during the digestion process. The energy that remains available after digestion and assimilation is called Net Energy. 

That brings us to the core insight: Ranchers are not just growing grass, they are producing, managing, and converting Net Energy into marketable products through their grazing animals. Net Energy is the true foundational resource of a grazing operation. This is why we say ranchers are Net Energy farmers. 

The National Research Council (NRC) has extensively studied the Net Energy requirements of animals in different physiological states–such as maintenance, pregnancy, lactation–under different environmental conditions,weight gain scenarios, and more. Ranch Vision incorporates this research along with user-provided inputs to calculate the Net Energy demands of the animals on a given ranch. 

To quantify this, Ranch Vision uses a unit called the Grazing Unit Month (GUM). One GUM equals 304.375 megacalories (Mcal)–the amount of forage needed  to provide 10 Mcal of Net Energy per day for one-twelfth of a year. 

While comparable to the traditional r Animal Unit Month (AUM), GUMs provide a more precise, nutrition-based metric that accommodates for differences in species, body weight, and production stage.

Your ranch’s projected forage consumption, measured in GUMs, is shown in the Grazing Demand Reports. These reports offer a clear baseline for evaluating forage use, supporting better decisions around grazing management and profitability.