Crusting: Manure & Flies | Healthy Farms

At Bioverse we understand that fly issues are more than what they seem. We know that barns with massive fly issues are not just an annoying issue. It can lead to maintenance issues not being resolved due to nobody wanting to spend another second inside the barn or anywhere near it.

Pig health and biosecurity are suffering due to flies. Flies are great carriers of disease and can help spread it throughout the barn but can also help spread disease from barn to barn and site to site. If you’ve ever been to a site with truly horrific fly issues, within the span of opening and closing the door of the vehicle, you’ll already have a dozen flies inside, ready to hitch a ride to the next barn.

It’s commonly known in the hog industry that one of the biggest underlying causes of a fly issue is dry manure. In a deep pit barn that has manure that stays liquid on top, the flies are at a normal amount for a hog barn. But once there’s dry manure on top (i.e “crust”), the normal amount of flies have just found a perfect habitat to lay their eggs. The entire life cycle of a fly from egg to adult can vary based upon temperature. In hot weather, it can be as low as 7-10 days, with it doubling and tripling in length in colder weather. The two most seen stages are the adult stage and the larva stage, otherwise known as maggot. These are the two stages we can do the most about.

Options of treatment:

  1. The Adult stage: Targeting the adult stage of the flies seems like the obvious choice. There are great insecticides out there like Tempo that have some residual and can make a world of difference. The problem though is it not only takes a lot of time to apply regularly, it can be difficult to apply to the most important area of the barn, the crust, where flies are constantly spawning the next generation.
  2. The Larva stage: The larva stage is the next generation that will replace the adults. There are some great larvicides out there that will reduce maggot populations considerably. Some like clarifly are available through the feed. The problem though is the disconnect between barn worker/contract grower, and the people who can actually change the ration. It’s also extremely expensive. At Bioverse we have a cost effective product in Biocide. This all-natural larvicide is safe to use and will not harm a single pig or even a fly, but it will harm the maggots. It’s a bacteria (Bacillus Thuringiensis, commonly known as Bt) that releases endotoxins for the maggots to eat. Application is easy as well. Simply spread the granules throughout the barn. It can also be rinsed in while power washing the barn between turns for complete convenience.
  3. Treat the Crust: At Bioverse this is what we specialize in, breaking down organic matter. Anyone who uses AgraSpheres or AgraSlats will already have a liquid top so there’s limited fly habitat. We also guarantee that if you do have any crusting, we’ll take care of it with our crust eliminating products for free. This is the easiest of all since it takes care of your manure pit but also only requires two quick applications a year.

If you have any questions or have a unique or particularly difficult crust to take care of, give us a call at 877-948-0303 or send an email to