Cow-Calf Certification Practice Exam

How do nutrient levels in grazed corn stalks change over time after harvest?

1. Nutrient levels steadily increase

2. Nutrient levels decline after initial grazing

3. Nutrient levels remain unchanged

4. Nutrient levels are significantly higher if grazed shortly after harvest

The correct answer is: Nutrient levels are significantly higher if grazed shortly after harvest

Nutrient levels in grazed corn stalks do tend to be significantly higher shortly after harvest due to the fact that the remnants of the corn plants, including leaves and husks, still contain a considerable amount of nutrients immediately following the harvest. During this initial period, the plant material is typically still green and has not yet begun to decompose, thus retaining higher nutrient values, which can benefit the grazing livestock. As time progresses after harvest, the quality of the stalks can decline because microbial activity and environmental factors begin to break down the plant material, leading to nutrient loss. This deterioration can negatively affect the nutritional intake of grazing animals. Grazing later, when the plant material has dried out and decomposed, can result in lower nutrient availability. Hence, grazing shortly after harvest maximizes the nutrient intake for the cattle. This is why options regarding nutrient levels steadily increasing or remaining unchanged are not accurate, and while nutrient levels may initially be high, they will decline after the initial grazing period rather than significantly improving.