Fly Management Practices in Livestock Herds without Using Pesticides

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July 1, 2019

By Greg Judy 

CLARK, Missouri:  We use a multiprong approach with our management to limit the number of flies that attack our livestock.  I will cover each of these practices in detail.    

 Hair coats.  The first practice that has paid huge dividends is selecting cattle that have very slick oily hair coats.  Flies hate landing on oily surfaces that make it tougher for them to take off when a swishing tail comes their way.  The oily surface is an awesome defense mechanism for any cow.  There should not be one trace of any winter hair coat left on your animals when you reach summer heat.     

Walk through your herd and see if you have any hairy animals that have not shed off.  The hairy animals will be covered in flies and they will not be performing very well.  It is almost like the cow is sending out a signal to the flies, come and suck all my blood out.  In natural settings anything that does not shed off gets eaten by a predator.  The animal gets thin, fails to reproduce and becomes food for a predator.  This is natures way of selecting for adapted animals that thrive in the natural environment in which they were born.       

We call these cows fly magnets and they must be sold immediately no matter what.  All they are doing is costing you money in the form of lost production and forage consumed.  Worse than that is the fact that they are a huge breeding site for additional flies to repopulate and attack the rest of your good animals.  Just by culling these animals from your herd, you have already made good progress in eliminating flies from your herd in the future.     

Rotations.  Next practice that really helps put pressure on flies is to manage your rotation such that you are distancing your herd from the previous cow pats.  We constantly stay ahead of the fly hatch that is taking place in the manure pats by moving our animals forward each day with full plant recovery periods before returning to graze again.       

In our area of the Midwest the fly hatch in the manure pats happens two to three days after the manure pat has been deposited on the ground.       

If you take your foot and push open a two-day-old manure pat, there are hundreds of white fly maggots squirming around in the juicy mixture.  This is the next army of flies that you are trying to out run with your grazing rotation.  If animals are kept in the same area for two to three days, the fly population absolutely explodes over the whole herd.     

Skip paddocks.  If you do not have another empty farm to walk your livestock and to escape the fly pressure there is another method that definitely helps with fly pressure.  Skip every other recovered paddock around your farm in your rotation and graze those paddocks that you skip on your return as you come back across your farm.  Every day you are putting a fresh un-grazed paddock between your animals and the previous grazed paddock with fly load on it.             

The skipping paddock method has another huge benefit attached to it in the form of not having a huge long cattle drive from one end of your farm back to the other end where you started your grazing rotation.  Because you skipped every other paddock on your first rotation across your farm, you have paddocks to graze on your return trip through the farm.     

High energy plants.  Grazing high energy plants that contain enormous amounts of oxygen is paramount to success.  With our twice daily moves of animals through our farms we are leaving one half to two thirds of the plant.  Our animals only select the best part of the plants.  They trample or leave the rest of the plants.  If we get in drought conditions, which seems to be happening more frequently, the longer grazed plants ensure that we have something in our pasture for our livestock's next rotation.     

Don't make the mistake of leaving the herd an extra day to make them graze the paddock like you think it should be grazed.  There are several bad consequences of leaving them an extra day.  First and foremost is that fact that the animals will go over the paddock and take a second bite off the plants that they grazed that first day.  Now you have done serious harm to the health of the palatable plants within that paddock.  By taking the second bite, these plants will need a much longer recovery period before they are ready to graze again.     The next bad consequence of leaving the animals an extra day is the fact that animal performance will plummet.  All the high energy plant tips were harvested on day one.  

Now you're making the animals eat portions of the plant that contain very little energy.  The final negative consequence of leaving the herd an extra day in the paddock is the fact that the flies have caught up with your animal herd and are sucking the blood out of them.     The high levels of daily animal performance ensures that your animals have the best immune system possible to ward off pests of all kinds.  If an animal has a compromised immune system the flies will find that animal and attack it with gusto.  If your plants get mature and all go to seed because of lack of grazing pressure, animal performance will go down.  Animals can select a perfect diet every single day if we allow them to with our management.  Want an open cow?  Limiting their daily consumption will accomplish this.     

Tree Swallows.  Our next line of defense against fly populations is our tree swallow bird populations.  I had never seen a tree swallow in my life until I put up my first tree swallow bird house.  Within two days a pair of tree swallows were nesting in it.  An adult pair of tree swallows can eat 8000 flies per day.  These guys enjoy eating flies and are the ultimate natural predator.  It is pure joy watching them dart around the field over the top of our livestock picking off flies in the air.     

These birds look like F-16 fighter jets in their aerial maneuvers.  Insects have no defense against these agile birds.  I went a little nuts on building and putting up tree swallow houses on all of our farms.  We now have 450 tree swallow houses up on the various farms.  Definitely getting some stares and coffee shop gossip about those crazy Judys with their bird houses!  I kind of get a chuckle out of it because most folks really think we have gone to the birds.  Before you try any tree swallow houses on your farm, google the nesting range of the birds to ensure that your farm is in it.     

Chickens.  While we are on the bird subject, we also have 550 laying chickens that are moved across the cattle farms.  It is impossible to keep up with our cattle rotation with our chickens because we are moving the cattle mob over large areas very quickly.  The fertility the chickens bring to our farm is mind boggling though.  Former broomsedge ridges are now lush grass/legume forage mixtures.  Am I concerned about the chickens eating the dung beetles?  No.  The dung beetles are mostly gone by the time the chickens are scratching through the manure pats.  If you don't have chickens on your farm, brainstorm a way to get it done.  Offer your farm for free to a young energetic couple looking to start their own egg laying operation.     

The dung beetles certainly help with fly control, but dung beetle populations have been decimated across the USA.  We still have dung beetles but not like we did when I was a kid growing up on the farm.  I remember going out to milk the family milk cow twice a day and seeing the enormous populations of dung beetles that thrive in our cow pats.     

These guys were monsters that rolled up the dung in nice round balls and buried it in deep tunnels.  We have never used any type of wormer on our own cattle because it destroys dung beetle populations and does not allow the cattle to build up resistance to parasites.  No fly tags or rubs are used against flies as well.     

Folks, the fly control tools that I discussed in this article work.  Don't get hood winked into thinking that your only option for fly control is purchasing something to pour on them or in them.  Whatever you put on your animal ends up in the soil with devastating effects on your farm's soil life.  You can do it, keep your money in your pocket not someone else's. 

Greg and Jan Judy graze South Poll beef cattle, parasite-resistant hair sheep, pastured hogs, and layers on 1620 acres in Clark, Missouri.  The farm includes 13 leased farms and three owned.  All animals are direct marketed as meat and seed stock sales.  Contact Greg at or visit

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