nodpa logo
resources banner


Organic Checkoff
Field Days Archives

NODPA Industry News
National News
Feed & Grain Prices Organic Pay Price
O-Dairy ListServ

Farmer Classifieds
Business Directory
Contact Us

Transitioning •   
Certification •   
Production •   
Recommended Books •   
Research Updates •   
Renewable Energy •   
Organizations & Links •   
Business Issues •   

Featured Farms

Support NODPA















Managing Flies on Your Organic Dairy Farm

By Dr. Paul Dettloff and Dr. Sarah Slaby

Added May 20, 2013. Flies (musca domistica) have been around since man appeared, and are not going away anytime soon. We have learned to cope with them the best way we can.

What is it that they do to irritate a dairymen?

Well, number one, they spread disease. Pinkeye, a bacterial infection, is spread from eye to eye by flies. Staph and strep plus, other mastitis-causing bacteria, are spread from teat end to tea end. You see, there is always a little residual milk at the end of the teat after milking. Flies gravitate to this very shortly after milking. Post dipping is a tool used to decrease this. There are now residual essential oil teat dips on the market that repel the fly for about 12 hours.
BVD and BRSV are viruses in nasal fluids that can be transmitted easily by flies.

There are basically three types of flies:

  • Face flies that hang around the face, muzzle, nostrils and eyes. Face flies lay eggs in fresh manure.
  • Horn flies are on the neck and especially the back area. Horn flies lay eggs in any organic matter - manure, rotted feed, wet bedding and uncleaned gutters throughout the summer.
  • Stable flies are the pesky ones on the legs and bottom side of the animal. They reproduce same as the horn fly. The stable fly is very irritating as they suck blood daily, though only for a short time. The rest of the time they fly around.

It takes about two weeks once a fly lays eggs until you get a new batch.


Kelp fed to animals, over a long term, will build significant iodine levels in the tissue of an animal, and flies don’t like iodine. Kelp-fed animals definitely have less pinkeye. A farm must use a multifaceted approach to attack flies. First, clean up the breeding area of manure and old organic matter.

Sticky tapes, the narrow reels you can uncoil, are really good. Avoid the very wide ones, as birds can get stuck on them. Various jars and baited jars also work well. A very good one is the Flies-Be-Gone fly trap. That one is a dandy.

Predator wasps that are let out periodically during the summer work well also. There are numerous companies supplying parasitic wasps. The mechanical walk through fly traps that vacuum them off collect literally thousands of flies. North Carolina State University is a leader in research in this area along with other companies of late.

A very ingenious farmer in Wisconsin by the name of Jahnke took a 55 gallon plastic barrel and put 2” PVC elbows in it with the elbows facing down. The elbows are on the sides ½ of the way down. Put a lid on it with a plexiglass window in the lid. Place a piece of placenta, chicken butchering leftovers or whatever will rot, and you have a fly trap that will last years. Just clean it out and hose it down! If you have any questions on this, contact either author of this article or Lancaster Ag Products for barrel design.

[Editor’s Note: You can go to NODPA’s website (under Resources) for an article on Jahnke’s Fly Trap: production_healthy_jahnke_flytrap_02_03_11.shtml]

Barn swallows are wonderful! Don’t destroy their nests as they eat their weight daily in insects, flys and mosquitoes. Purple Martins are beautiful insect eaters. Many farms have the manufactured white gourds above the calf hutches. They look really attractive and give a farm a humane touch. Encourage bats by putting up bat houses as they live on insects and flys. Muscovy ducks are notorious fly catchers. They were very common in the Midwest in the 1950’s.

The other tool for to keep down your fly population is the new essential oil fly sprays that have been developed recently. They have gotten better and better. Essential oils are safe for humans to touch and breathe. The era of toxic, long lasting fly-deadly sprays needs to come to a close as the side effects show up down life’s highway.

As you can see, there are a lot of tools. Cherry pick this list for your farm with sanitation being first.

Dr Paul Dettloff has a large animal practice in Arcadia, Wisconsin, and has worked with CROPP Cooperative (Organic Valley) as a consulting veterinarian since 2002. He is the author of a popular book titled ‘Alternative Treatments for Ruminants Animals’ and has his own product line of Dr Paul’s Health products for livestock. You can reach Dr. Paul Dettloff by email at: or call: (608) 323-3047.

Dr. Sarah Slaby is located in Arcadia, Wisconsin, and specializes in Organic and Sustainable Agriculture. She has her own line of natural products for treating dairy cows and shares a holistic approach to her practice not only for her organic and biological clients, but for her conventional herds as well. You can reach Dr. Slaby by email, phone, or visiting her website:, (608) 323-3005,

NODPA, 30 Keets Rd, Deerfield, MA 01342 FAX: 866- 554-9483 PHONE: 413 772 0444