Dung beetles accelerating cow patties' decomposing process are beneficial to beef producers, allowing nutrients to return to the soil sooner than would happen without them.
"Dung beetles may have a questionable reputation due to their name and their 'home,' but they are very beneficial in pasture ecosystems," said Dirk Philipp, associate professor of forages at the University of Arkansas System Division of Agriculture.
The process starts when the beetles feed on the patties by sucking out the moisture. If it's a warm day, the dung beetles move in soon after the patch has been dropped on the field. If the beetles work quickly, a patch can decompose within hours.
Quick removal of the patties means cows will not need to avoid grazing close to patches, so there will be more forage growth even as nutrients are distributed across a larger area.
"It has been shown that if patties sit undisturbed, up to 80% of the nitrogen may be lost," Philipp said. "If the dung beetles can do their work, most of it is recovered."
The beetles also reduce the patties' methane emissions by digging holes and little tunnels in the patties that aerate them and prevent the production of methane. The soil benefits from quicker incorporation of organic material and aeration that helps increase water infiltration rates.
The bad news is that dung beetle populations appear to be declining in recent years, Philipp said, possibly as a side effect from treatment of cattle for parasites with internal drugs.
Helpful alternatives would be to use pesticides formulated in cattle's ear tags, spray-on insecticides or treating the animals with the drugs during colder months when dung beetle populations are already low. Check with a veterinarian for the optimum treatment for your animals.
The beetles' population level is also affected by grazing management that determines over how wide an area the patties are distributed. If the patties are concentrated in a small area, the convenience of an abundant food source will cause the population of beetles to be higher than would be present in patties spread across a larger area.
Philipp advised producers that they can find out whether dung beetles are present by checking the patties in their fields to determine if they have holes in them, if they appear to be shredded and if they're disappearing quickly.
Source: University of Arkansas