Why “Take Half, Leave Half” Is Not a Universal Rule By Jim Gerrish

🎙️ Episode Title: Why “Take Half, Leave Half” Is Not a Universal Rule
📝 Featured Speaker: Jim Gerrish

In this episode, Jim Gerrish, a renowned grazing management expert, challenges the traditional “take half, leave half” rule and explores why it may not be the best approach for every grazing situation. Drawing from his vast experience as both a researcher and practitioner, Jim explains how this guideline can vary greatly depending on environmental factors and management goals.

🔑 Key Points Covered:

1. Understanding Utilization Rates: Jim clarifies the difference between seasonal utilization rate and temporal utilization rate, explaining how they impact grazing management in different contexts.
2. Missouri Research Insights: He shares findings from his time at the University of Missouri, where initial studies on pasture mixtures showed that achieving exactly 50% utilization was challenging and not always optimal.
3. Lessons from Idaho: Moving to Idaho, Jim observed that irrigated pastures allowed for higher utilization rates, sometimes up to 70%, without detrimental effects—contrary to what he experienced in Missouri.
4. Rangeland Realities: In arid environments of the West, Jim found that the “take half, leave half” rule was too aggressive and recommended a more conservative approach, with utilization targets as low as 20% in low-biomass production areas.
5. Impact on Animal Performance: Jim discusses how different utilization levels can affect individual animal performance, emphasizing the need to balance plant health with livestock productivity.

🌱 Actionable Insights:

1. Adapt Strategies to Environment: Adjust your grazing management approach based on local precipitation and forage production, rather than following a single rule.
2. Monitor and Measure: Use tools like clipping and weighing residual forage to accurately measure utilization rates and refine your grazing plan.
3. Prioritize Plant Recovery: In low-biomass environments, focus more on what you leave behind rather than what you take, to support plant community resilience.
4. Consider Animal Needs: Balance grazing intensity with the nutritional needs and performance goals of your livestock.
5. Use a Sliding Scale: Develop a sliding scale of utilization targets based on your specific environmental conditions and forage productivity levels.

To learn more about Jim Gerrish’s work and his approach to adaptive grazing management, check out the show notes for links to his books and resources on Management-intensive Grazing. Be sure to explore our monthly magazine, live events, and latest specials. 

For more insights and resources, be sure to check out our monthly magazine, live events, and the latest specials here.