In his previous life as police officer and, later, a police prosecutor, Bruce Wilde reckons he had to cut through a fair bit of bullcrap. In his “retirement” he’s dealing with sheep crap and he’s enlisted some little critters to help.
Bruce runs Cambray Cheese at Cundinup, in WA’s Margaret River region, with his wife Jane, son Tom and his daughter-in-law Maddy, eight employees and a whole team of dung beetles.
The Wildes, who first introduced the Bubus bison species of dung beetle to the farm in the late 1990s to help reduce the flies hanging around the dairy, are working with the Dung Beetle Ecosystem Engineers (DBEE) project by helping breed up the Bubas bubalus beetle.
Twice a week Bruce attends to the dung beetle factories – created out of old apple crates lined with hessian – by adding a small shovel full of sheep poo taken from the pile of manure created by cleaning out the sheep dairy.
“It doesn’t take too much effort at all and I don’t think any have escaped yet,” he said.
But the Wildes won’t mind if there are a few getaways. Bruce thinks they might be the ideal species to fill the seasonal gap (late winter to midsummer) in current dung beetle activity.
“When we first started the dairy the flies were so bad we’d be milking wearing fly nets and we had to install fans to try and move them away. The flies gave the sheep hell,” he said.
“Now we barely see a fly in there. I think it’s because the beetles bury the fly eggs so there’s never a chance for the population to get too big.”
But the real gains have been in the paddock – namely with soil improvements due to the tunnelling and burying of the manure by the beetles which supports better water use efficiency and pasture production. Bruce is exploring adding biochar to the system. Biochar would be fed to the sheep in a molasses mix and, following the digestive process, would be incorporated into the soil by the beetles.
“(If we adopted this system) by 2030, you could have soil a foot deep instead of three inches deep with the moisture going down to that depth,” he said.
“This would reduce the reliance on fertiliser. Of course, you’d then monitor the soil health with tests and tissue samples and just fertilise when you need it.”
“While I wouldn’t risk going without having a shed full of hay as back up, I’d think this sort of system could really boost pasture production.”
Good health is essential for dairy ewes to maintain high production, especially at peak times of year when the higher producing Cambray Cheese ewes are producing 1.8 litres/day in two daily milkings with twins or triplets at foot. At optimum production the best performing ewes produce enough milk to create $300 worth of cheese a week.
“They’re dairy animals, which means they’re pretty soft. You have to look after them. We use strip grazing with one or two electric tapes so they’re always moving on to fresh pastures, which we top up with a dairy pellet ration to maintain milk volumes,” Bruce said.
Quality pastures combined with the quick disposal of manure by the dung beetles helps the Wildes keep the internal parasite burden low.
“Tom’s set up to do all our worm egg counts here on the farm, so we monitor it pretty closely. We drench the young animals as needed until they get going but our mature dairy ewes can go for up to four years without needing a drench,” Bruce said.
“Once the sheep have eaten down a pasture and we’ve moved them out, the sheep poo is all gone within eight to 10 days. And you should see the pile of dirt the beetles have dug up where the poo was. They must go down deep.”
While the Wildes know their cheese sales are driven by consumers looking for a healthy alternative to cows’ milk or for a unique locally produced food experience, Bruce is seeing more and more interest in food which is produced in a clean, sustainable environment.
“Dung beetles fit neatly into that sustainability story when we are dealing with chefs and the food industry. Chefs and customers love coming out here to see what we’re doing and they always go away saying ‘keep it up’.”
DBEE project researcher Dr Russ Barrow of Charles Sturt University, Wagga Wagga, NSW, said research backs up Bruce’s claims about improved control of internal and external pests.
“For a start there is never any dung left around the farm to attract flies and while the dung beetle themselves don’t eat the fly eggs or larvae, other beetles do and healthy landscape attracts a range of beetles,” he said.
Removing the dung also removes a potential location for flies to lay eggs, Russ added.
By disrupting the breeding cycle of nematodes (round worms), dung beetles are also helping producers manage internal parasites.
“We've got a lot of producers who, with good dung beetle diversity, activity and abundance, don't drench. They monitor the situation with worm egg counts. I’m not saying stop drenching if you have dung beetles as there are a lot of compounding factors impacting the number of internal parasites, but if you have a low egg count and stock are well managed then reduce drench use if you can,” Russ said.