Agronomy Degree Practice Exam

Which forage crop is associated with a risk of prussic acid poisoning for livestock?

1. Sorghum stalks

2. Tall fescue

3. Alfalfa

4. Winter wheat

The correct answer is: Sorghum stalks

Sorghum stalks are known for their association with prussic acid poisoning in livestock, particularly when the plants are stressed by conditions such as drought, frost, or rapid growth. Prussic acid, or hydrogen cyanide, is produced when certain compounds in the sorghum plant break down. This risk is particularly heightened in young, freshly cut plants or when livestock graze on regrowth after cutting. Understanding the conditions that lead to prussic acid accumulation is crucial for anyone involved in livestock management. For example, if sorghum is allowed to recover after a stress event or is not properly managed during growth stages, the potential for toxin buildup increases significantly. This toxicity can cause serious health issues or even death in livestock, making it critical for farmers and agronomists to recognize the risks associated with this forage crop. In contrast, other options like tall fescue, alfalfa, and winter wheat do not typically pose a similar risk of prussic acid poisoning. While they may have their own concerns regarding livestock grazing, they are not associated with the same level of prussic acid risk as sorghum. This highlights the importance of crop selection and management practices to ensure animal safety.