By Brad Schmitt, DVM, Four Star Veterinary Service, LLC
Biosecurity in a hog operation usually focuses on people and practices like showering in, UV irradiating supplies and filtering incoming air. But rodents and insects can bypass all those critical control points on a hog farm.
Biosecurity is only as good as its weakest link, so pest control needs to be a top priority, whether you’re operating a genetic multiplier, sow farm or a wean-to-finish barn.
Spread disease, damage property
Rodents and insects act as mechanical vectors to introduce new pathogens into naïve populations from the outside world. These pests will spread dormant viruses from a manure pit to the pig level. The viruses may include porcine reproductive and respiratory syndrome, porcine epidemic diarrhea, sapelovirus and teschovirus.
The pests can also track bacterial pathogens like Lawsonia and Brachyspira (swine dysentery) from pen to pen or crate to crate.
Rodents and insects including ticks, lice and biting flies also propagate diseases like leptospirosis, Mycoplasma suis, swine pox and African swine fever.
Rodent populations, when left unchecked, can cause significant damage to swine facilities. They can quickly deteriorate curtains, walls and insulation, leading to costly, ongoing repairs. In addition, ventilation and temperature controls are compromised when buildings deteriorate, which negatively impacts pig performance.
Feed waste erodes workplace
Feed wastage occurs from rodents eating and digging through feeders and pushing feed into the pit. This may not seem like a big deal, but a large population of rodents can really amplify the issue. In today’s economic climate, every penny counts.
In addition, pest infestations make for undesirable working conditions. In an era where steady farm labor is hard to secure, it’s important to provide an optimal work environment.
If you’ve ever inhaled a swarm of gnats, donned a mouse-inhabited boot or showered-in with cockroaches, you’ll understand the impact that pest control can have on workplace satisfaction.
Setting up effective rodent control
Effective rodent control starts with a rodent audit to assess the situation, sometimes employing the use of infrared surveillance cameras to monitor night-time activity. This process determines points of entry, heavily infested areas and paths most travelled. Once these are determined, bait stations can be strategically placed inside and outside of barns. Spacing and location of bait stations will depend on mouse versus rat infestation in addition to other factors.
Bait-station maintenance should be done on a regular basis, with frequency depending on the severity of infestation. One or two people should be designated to this task, as giving ownership of the process helps with compliance. Ongoing assessment of bait disappearance will determine if bait rotation, supplementation or adjustment of stations is necessary.
Bait rotation important
Bait rotation is periodically used to change the active ingredient, flavor and texture. Doing so prevents monotony and promotes bait intake, which prevents resistance. This can also be accomplished by rotating between anticoagulant and neurotoxin-type baits, especially in cases where the resident population becomes resistant to one mechanism of action. For example, as anticoagulant resistance starts to build, neurotoxin baits are implemented to reduce the resistant population, then anticoagulants again become an effective mode of control.
Just because one particular bait has been effective on your farm in the past does not mean it should be used continuously. Rotation of baits will preserve that efficacy for the long-term future.
While rodenticide can be an effective means of rodent control, prevention must also be practiced. Management practices to eliminate rodent habitats and feed sources are an integral part of keeping the population to a manageable level.
By removing debris and vegetation from the building perimeter and creating a 3-foot-wide buffer zone with coarse gravel, rodents are deterred from entering or burrowing under the barn. In addition, timely clean-up of feed spills and maintaining leak-free bins and augers prevent the rodent population from flourishing.
Much like rodent control, an insect-control plan starts with identifying the target and being familiar with its life cycle. Some insects such as flies lay eggs and persist in the environment, while mites and lice require a host to survive.
Insect life cycles and hatch times dictate control strategies and dosing frequencies. When selecting insecticides, look for those with a longer residual effect, reducing the need for frequent application.
Many great insecticides exist, but none are effective at killing all species. For this reason, multiple products and routes of exposure may be warranted. Combinations of premise sprays, injectables, pour-ons and feed-grade insect growth regulators may be used in addition to proper sanitation.
Sanitation is crucial as flies and other insects are attracted to manure. By thoroughly cleaning and disinfecting barns between turns, minimizing manure build-up while pigs are present and keeping pits pumped down to acceptable levels, fewer insects will reside at animal level.