Harrowing Pastures
“Feldarbeit” by Rebel, licensed via Adobe Stock
Is harrowing pastures an effective way to control parasites in horses?
Harrowing horse paddocks for parasite control involves using a harrow to break up manure piles and expose them to sunlight and air, which helps kill parasite larvae. This method is most effective when pastures are harrowed at least once a year, ideally after the grazing season. Harrowing can also help smooth out areas where horses dig up the soil on wet ground. Harrowing pastures can be a useful tool in parasite control, but it's not a complete solution. It's important to understand the limitations of harrowing and combine it with other management practices for effective parasite control.
Here's a more detailed look at how harrowing helps with parasite control:
Breaking up manure piles:
Harrowing disperses manure, preventing the formation of concentrated piles where parasite larvae thrive.
Exposing larvae to sunlight and air:
Sunlight and air exposure dehydrates and kills many parasite larvae.
Spreading manure:
Harrowing helps spread manure evenly across the pasture, which can help reduce the number of manure piles. It can be beneficial for nutrient cycling and preventing overgrazing in certain areas. But harrowing can also spread parasite eggs and larvae further across the pasture if not timed correctly.
Improving soil aeration:
Harrowing can improve soil aeration, which can further help reduce parasite populations. It also encourages grass growth, and removes dead grass and weeds, which can improve pasture health overall.
When to harrow:
Late winter or early spring:
This allows the ground to dry out before harrowing, which can help avoid damage to the soil.
After the grazing season:
Harrowing after the grazing season can be particularly effective in reducing parasite populations.
Dry conditions:
Harrowing is most effective when the pasture is dry, as this allows the manure to dry out and be exposed to the sun and UV rays, which can kill parasites.
After grazing a paddock:
Harrowing after moving horses from a pasture can help spread manure and reduce parasite numbers.
Before resting pasture:
Harrowing before resting pasture can also help break down manure and allow it to be exposed to the elements.
Harrowing is not a substitute for other management practices: Harrowing is most effective when combined with other strategies, such as pasture rotation, dung removal, and appropriate deworming programs.
Other methods of pasture management for parasite control:
Moving horses to new pastures regularly:
This helps prevent the build-up of parasites in a specific area.
Removing manure piles:
Regular removal of manure piles can help reduce parasite populations.
Using sheep as "paddock cleaners":
Sheep can help consume some weeds and can also help to clean up some of the parasite burden.
Consider using a fecal egg count (FEC) to identify and target high-shedding horses for treatment:
This can help reduce the overall parasite burden in the herd
In conclusion, harrowing can be a helpful tool in parasite control, but it's not a standalone solution. By understanding its limitations and combining it with other management practices, you can create a more effective parasite control program for your horses
Reference: Information adapted from equine pasture and parasite control guidelines from Virbac Australia, the American Association of Equine Practitioners (AAEP), and various Australian state agriculture departments (e.g. DPI NSW, QLD DAF).
See also: https://aaep.org/guidelines/internal-parasite-control-guidelines
