Optimizing Pasture Health: A Practical Guide To Implementing "Take Half, Leave Half" Grazing

When making changes to your beef cattle operation, starting with simple manageable steps is the key to long-lasting improvements. This is the case when it comes to the concept of “take half, leave half,” which is a basic rule of thumb for grazing management that can be effectively implemented in any region, in good weather years and bad.

In a recent video from the BCRC, Dr. Breeanna Kelln, adjunct professor at the University of Saskatchewan and a farmer/cow-calf producer north of Regina, demonstrated two methods to determine available forage and how to estimate when 50% has been utilized. Kelln explains, “Leaving behind some green material is important to ensure that plant can still photosynthesize and take energy back down into those roots so the pasture can persist and overwinter.”

Take Half, Leave Half – Method 1
Method 1 uses height as a quick and easy strategy to estimate the forage volume available to graze. Simply measure the height of your desirable forage in approximately 20 different spots, record the average height and then move cattle off that stand once that average height is cut in half.

Take Half, Leave Half – Method 2
Method 2 uses weight, which is more labour-intensive but more accurate to assume when 50% of the plant material is utilized. This entails cutting a few samples of forage from the pasture as close to the ground as possible, binding the bottom with an elastic band, and then finding the middle point by balancing the sample on your finger until the forage rests even and straight. Finally, cut off the plant material at the top, which allows for a visual representation of what the growing plants will look like once 50% of the plant material, based on weight, has been utilized.

Either method is an effective way to begin to recognize what you are starting with and what 50% utilization actually looks like.

Key Considerations

• Only look and measure the main nutritive forage in the pasture stand. Do not include undesirable or antinutritional weeds or plant material.
• Take measurements before cattle are let onto that field, ideally immediately before introducing them to the new piece.
• The more you graze, the more time that pasture needs to rest.
• Knowing the plant species in your pasture can help you to strategically graze throughout the season.

When taking these pre-grazing measurements, be sure you are only including the portion of the pasture that will be consumed by cattle. For example, if your pasture is half weeds and half forage, grazing the forage right down to the ground while the weeds remain untouched is not the “take half, leave half” principle. In this case, you would only consider the desirable forage portion of the pasture, which accounts for 50% of plant mass, meaning that 25% of the total plant mass on the field will be utilized to effectively apply “take half, leave half.”