Ashley Englin, Swine Specialist
Northwest Iowa has not been a stranger to rain and humidity this year. With the wet spring came several mosquitos and other insects. These insects have been causing an issue for producers when sending their pigs to market. The processing plants have been making deductions for pigs that arrive with large amounts of insect bites. Insects have always been a pest that producers must manage this time of year, but the hot weather mixed with excess moisture is making this year especially hard.
The Iowa Pork Industry Center has put together a reference sheet for growers that has best practice references to help lessen the effects of mosquitos at sites.
The first focus is site maintenance. Ensure that all manure, spilled feed, and wet bedding are managed and disposed of properly away from the barns. Any compost facilities should be checked to make sure standing water is not present and all mortalities are properly covered. Rendering boxes are best kept away from the barns and facilities.
The grass around sites should be kept short to prevent insects from having nesting places and habitat. It is suggested to have a rock buffer around the perimeter of the building. This helps to ensure that the grass does not get too close to the buildings and helps with drainage. Having proper drainage can prevent water pooling and stagnant water that can attract insects, especially mosquitoes. Make sure that the rock buffer is free of weeds because the weeds can also harbor insects.
Curtains are also a place that can hold water. Manually raising and lowering curtains to drain rainwater can prevent stagnant water in this area.
If using a sprinkler system, it is best not to run it at night and to run it on an interval timer to reduce the chances of creating standing water in the barn. Daily walk throughs should be done to ensure no standing water anywhere in the barns. Lighting should be limited at night. Adult insects are attracted to light, having barn lights turned off after sunset can prevent the insects from being attracted into the barns.
Ventilation plays a key role in reducing the effects of insects. In naturally ventilated barns there is less air flow at night due to the decrease in wind. One way to keep air moving is to have stir fans run throughout the night by adjusting the temperatures at which the fans turn on and off. This increased air movement should not create a problem for pigs over 150 pounds. For tunnel ventilated barns one option is to decrease the set point to keep air moving throughout the night. If there is poor air movement in tunnel transition, in the first tunnel stage, when the tunnel curtain begins opening, make sure the inlets are 100 percent open and in the second tunnel stage, make sure the inlets are reduced to about 50 percent open.
For more information on what can be done to control insects, please look for the detailed fact sheet at https://ipic.iastate.edu/information/InBarnInsectManagement.pdf.