There is much more to the grazing land we use for our horses than might first meet the eye. Part the grass and with any luck you’ll find a complex ecosystem of flora and fauna that helps support the land itself. To celebrate this amazing creature, we take a close look at the dung beetle, its role in our pastures and why we need to take greater care of these amazing creatures.
Herbivore dung is a rich resource of food and shelter for beetles, flies and wasps. These insects have evolved to rely on an animal waste product that is in plentiful supply and in return they play a major part in the decomposition process; without them we would all be knee-deep in it! Turn over a fresh dung pile and there should be hundreds of dung beetles and other insects present.
MORE ABOUT THE DUNG BEETLE
There are around 60 species of dung beetle in the UK with approximately 50% of which are rapidly declining and are listed as threatened. According to ecologist, farmer and TV presenter, Dr Sarah Beynon, the dung beetle population is “a great indicator of the environment and how healthy that system is” (podcast for National Insect Week 2014). The more the merrier!
Dung beetles can break down large quantities of faecal matter by eating and nesting in it, some species tunnelling it into the ground to use as food and insulation for eggs. These actions are categorised into three groups of dung beetles: Dwellers, Tunnellers and Stealers. The dweller beetles will live and reproduce within the dung, using it as a food source and a place to lay eggs. Tunnellers make burrow into the ground, taking dung with them for their larvae to feed on. This type of dung beetle helps to improve the soil structure. These actions increase organic matter in the soil, improving its ability to retain water and increasing nutrient availability to plants as well as aerating the land - beneficial for both root structures and other organisms. The stealer type will take advantage of tunneller beetles by using and living in existing tunnels, laying their eggs in the previously buried dung.
Horses can produce around 3-5% of their body weight in dung every day. For an average 16hh horse that’s around 18kg of dung a day or 6.5 tons every year! If we spend half an hour poo-picking every day, that is over 182 hours a year on removing dung from our pastures! Making these insects a healthy habitat in your pasture will reap rewards over the coming years. Dung beetles are very helpful pasture friends and worthy of your consideration- some species will fly in from up to 10 miles away for the right poo!
Despite the minimal study of the Dung Beetle in the equine industry to date, the Dung Beetle has also been credited or their role in reducing helminth (worm) transmission. These clever creatures feed on liquid-rich faeces, therefore, increasing the chance of ingesting the helminth eggs and could lower pasture contamination with infected larvae. Helminth eggs generally hatch within 3-4 days in their optimal conditions.
Ideally, when we are actively poo-picking twice a week (and bearing-in-mind the Dung Beetle prefers fresh dung); the Dung Beetle is working simultaneously at reducing the parasite infection on the pastureland alongside us every day.
These invaluable insects are a crucial part of our grassland ecology and certainly deserve to be considered when we are considering our pasture management and parasite control efficacy; let alone our wider ecosystem where the dung beetle is integral for many ecological functions such as nutrient cycling, secondary seed dispersal and the loss of N2 due to ammonia volatilization and a valuable food source for many species in our ecosystems.
HOW CAN WE PRESERVE OUR DUNG BEETLE POPULATION?
To poo pick for parasite infection or to preserve habitat for dung beetles, it’s a tricky conundrum! The two can seem counterintuitive at the outset.
On one hand poo picking is the best way to break the lifecycle of parasites on the pasture without having to rely on chemicals. But fresh dung is also essential for our dung beetles, these little critters play an important role in managing animal waste naturally, negating the need for all that heavy labour and giving a host of added benefits to the land, if we let them.
So how do we get the balance right?
Horse health and the environment are both equally important considerations.
- Start by making sure your parasite control programme is working. A regular testing programme will identify any problems in the herd and allow any ‘wormy’ individuals to be treated accordingly. Avoiding blanket treatments to the whole grazing herd means there is always some non-toxic dung available to dung beetles. You may need to worm more often and poo-pick with greater frequency in the beginning to reduce infection levels.
- Knowing that worm eggs in the dung hatch within 4-5 days; if we poo-pick twice a week this offers the dung beetle their optimum time for carrying out their integral work (up to 48hrs) to work harmoniously on the pasture. Start by leaving the freshest piles on the pasture and clearing them after roughly three days.
- Be aware of which chemical you’re using and which parasite you’re treating for. Where you do need to give a wormer, consider stabling horses for 48-72 hrs afterwards or at least restrict to smaller paddocks that can be easily and more regularly poo picked. This is both to limit exposure to chemical toxins for dung beetles and to reduce incidences of reinfection particularly of tapeworm for the horse.
Of our five licenced wormers for horses, ivermectin is the most toxic to dung beetles and moxidectin is also moderately toxic to them. Non-metabolised excreted ivermectin for example, can have a harmful impact on our environment too! Fenbendazole is considered to be a “safe” chemical for Dung Beetles! [Read more about ecotoxicity in our Info Zone] - If you can, worm when dung beetles are less active – during winter months (November to February).
- Is my muck heap enough of a habitat? In short, no! Dung collected from treated horses can be placed in carefully situated manure piles and allowed to rot down. Although dung beetles are attracted to muckheaps, they generally don’t breed in them.
It might seem counterintuitive at the outset, but if we can focus on our pasture management to reduce parasite infection and preserve a habitat for dung beetles; there are wins all round for horse health and the wider environment!
Prepared by Westgate Labs in partnership with Dr Beynon's Bug Farm & Dung Beetles Direct.
Find out more
We loved this helpful article in Horse and People by Mariette van den Berg, and while it talks about dung beetles in Australia there are some great takeaway messages for UK horse owners too: https://horsesandpeople.com.au/encouraging-dung-beetles-on-horse-properties
National Insect week is run every two years by the Royal Entomological Society and supported by a large number of partner organisations with interests in the science, natural history and conservation of insects. More information at www.nationalinsectweek.co.uk