When Wepar farmer Jeff Dowdell noticed some patches of his pasture were healthier than others, it got him thinking. Investigations over several years revealed that dung beetles were the source of his healthy grass.
“Back in the 1970s, the CSIRO released dung beetles in the South East to improve soil health, and they’re prolific here now,” said Jeff, who milks 250 cows in a herringbone dairy set on about 700 acres, with his son Wade.
“The dung beetles bury the cow manure to about six inches. This takes the nitrogen and phosphorus in the dung to the grass root zone, and the grass grows beautifully.
“I started buying different dung beetle breeds in 2018 as you need 2,000-odd for one dung pat, and different breeds are active at different parts of the year. But once you purchase them and rear them out, you can forget about them, and they do their thing, year after year.”
Jeff purchased his beetles from Australian dung beetle expert John Feehan, who says the key benefits of dung beetle activity in grazing paddocks include improved soil aeration and fertilisation, deepened topsoil, increased microbial activity and increased worm activity.
An added benefit is that dung beetles reduce bush fly populations by up to 99%, according to CSIRO research in Western Australia.
“I’ve read that between 2,000 and 3,000 bush fly eggs are laid in one cow pat. But they can’t survive if the dung beetle disperses it or takes all the moisture out, so the fly can’t breed,” Jeff said. “Flies don’t seem to bother us much here.”
Pest control is a critical component of all food safety programs. Effective fly control at the dairy can improve food safety outcomes by reducing the risk of contamination. Flies can carry bacteria like E. coli, Salmonella, and Listeria from manure or other environmental sources to feed, udders, milking equipment, and milk storage areas.
Fly control limits the ability for them to transfer pathogens to milk, reducing the risk of cross-contamination and strengthening sanitation practices.
Jeff said while reduced fly numbers were welcome, the biggest benefit for him was the reduction in synthetic fertiliser due to the work of the dung beetles, which was a significant cost saving.
“In my experience, adding nitrogen fertiliser makes the grass grow too quickly, and the trace elements, which are all benefits to the cattle, can’t keep up,” he said.
“I hardly ever put out fertiliser now, and while we don’t get as much grass as we used to, I think we’re getting better quality grass, and the cows are healthier – and this is where the dung beetles help – because the grass has got every bit of nutrient in it that they need.
“I’m a firm believer in healthy plants. If you have healthy plants with thick cell walls, insects like red legged earth mites can’t chew through them.”
Dung beetle expert John Feehan said dung beetles could reduce artificial fertiliser application significantly.
Burying dung positions 80% of the nitrogen in dung under the roots of the grasses in your pastures as well as many other valuable trace elements including phosphorus,” he said.
Jeff said that while his milk quantity was slightly below average, his milk quality was high, with cell counts around 100,000 cells/mL.
“We have a very healthy herd, partly due to good nutrition, thanks to the dung beetles, and partly due to our commitment to culling to keep herd genetics high,” he said.
Jeff is now focused on sourcing a dung beetle breed that is active in spring and early summer, which was a gap with his current breeds. He said there are many different varieties of beetles available from countries including Africa, South America and Europe.
“Dung beetles don’t all go all year round. They have different activity times. Some can handle heat and some can handle cold, so we need different varieties to get us through the entire season,” he said.
For more information on dung beetles, visit https://dungbeetleexpert.com.au/