On/Off Grazing can Minimize Pasture Damage in Wet Conditions

Spring grazing often involves managing wet conditions. Pugging (also called poaching) is hoof damage that creates divots in a pasture and exposes grass roots and bare soil. This kind of damage can reduce pasture yields, and the uneven surface may make haying operations difficult. Not grazing during these wet conditions is an option, but with rapid spring grass growth delayed grazing makes managing grass quality even more difficult. Research in Ireland has shown that cattle with unrestricted access to pasture spent only 37% of their time grazing (Kennedy et al., 2012). Livestock do the least amount of pugging damage to a field when they are grazing. Other activities, such as visiting the water trough or mineral source, lying down, or socializing cause more damage.

Researchers studied restricting the amount of time that cattle spent on pastures to try to reduce pugging damage. They found that cows can eat their daily forage dry matter intake during two 3-hour periods each day, and spend 98% of their time on pasture grazing under this type of management (Kennedy et al., 2012). This has led to the development of a management technique called on/off grazing, where cattle are let out to graze for three hours in the morning, then brought into a barn or dry lot until they are turned out to graze for another three hours in the afternoon or evening. For each grazing interval they are only given access to the amount of grass the herd can eat in that time, so it is a modified form of strip or block grazing. The Irish study showed that when cows were not restricted in the time they could graze, pugging damage resulted in 20% less grass yield compared to the on/off grazing management.

Another way to minimize pasture damage is to use several gates. If the herd enters the paddock through one gate and leaves through a different gate the traffic through each gate area is cut in half. This decreases the amount of pugging and soil compaction around gates. Leaving behind more residual grass can also help protect the field from pugging damage. In tame pastures, leaving 10 - 15 cm (4-6 in.) might be appropriate under wet conditions.

References

Kennedy, E., O'Donovan, M., Delaby, L., and Boland, T. 2012. Strategies to increase the length of the grazing season for spring and autumn calving cows. Teagasc Technology Updates.


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