The ultimate test for plant quality or acceptability is to feed it to an animal. Essentially, an animal doesn’t care if you produced 40 bushels/acre or 400 bushels/acre…it just wants to be fed. However, total yield is not sufficient and is a poor indicator of nutritive value (9). Instead, the goal is to create a highly nutritious plant (e.g., sugars, amino acids, fiber, micronutrients, calcium, etc.) that is easily digestible and 100% available. If a crop is poor in quality, it might take more food to satisfy the nutritional needs of the animal. Conversely, if the plant is fortified with essential elements, the animal would get more out of eating less!
Animals also give back to the soil, thus completing the nutrient cycle. In many production systems, crop yield benefits from manure application because it increases plant nutrient availability and it improves soil structure (8). Essentially, you are what you eat…what goes into the soil, goes into the plant, and goes into the animal also goes into you!