Don’t forget rodent, insect control during biosecurity checks

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

Brad Schmitt, DVM

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.

Insect-control tips

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.

 

 

COVID-19 lesson for hog farms: Tighten up basic biosecurity

The COVID-19 outbreak reinforces what veterinarians and pork producers already know — biosecurity protocols control disease.

“I think COVID-19 has given everyone a good refresher on basic biosecurity practices,” said Brad Schmitt, DVM, Four Star Veterinary Service. “We need to keep this momentum going in the fight against African swine fever and other viruses like PRRS (porcine reproductive and respiratory syndrome) and PED (porcine epidemic diarrhea).”

As a reminder, Schmitt offers suggestions to help producers tighten up biosecurity in their hog units, from people and vehicle traffic to room biosecurity.

Premise-level biosecurity

Biosecurity at the premise level requires all vehicles entering the farm to be washed and cleaned. This includes cleaning the interior of the vehicles. Wipes containing citric acid are recommended for cleaning steering wheels, radios, leather and vinyl seats, and other high-touch areas. A phenol-based spray product works well for disinfecting other interior areas of vehicles including cloth seats.

“A great habit is to use the aerosol spray to hit your boots when entering and exiting vehicles,” said Ryan Pusey, animal protein account manager, Neogen. “Hand sanitizer also should be used when entering and exiting vehicles. A foaming hand sanitizer will last longer and provide better coverage than a gel sanitizer.”

All people including personnel entering the facility must, at a minimum, cross a clean-dirty line indicating the boundary of the hog facility. Anything outside of the line is “dirty” and could contain potential pathogens.

The simplest indication of a clean-dirty line is an entry with a physical barrier such as a bench. People leave their personal items and shoes on one side and rotate to the other side where they put on clean boots.

When entering and exiting any facility, boots should be treated with the aerosol spray and a foaming hand sanitizer used.

Many facilities require a shower when crossing over the clean-dirty line to enter the barn. All personal belongings are kept on the outside of the shower by the entry. Once through the shower, clothing and boots are available for the clean side where the hogs are housed.

“Once we master premise-level biosecurity, then we hone in on room-level biosecurity,” Schmitt said. “The goal here is to reduce the spread of enteric pathogens that cause piglet scours.”

Boot baths

Boot baths prevent tracking in pathogens from one room to another. The bath must be kept clean and filled with disinfectant.

“Keep in mind that manure should be washed from boots before using the boot bath because you can’t effectively disinfect surfaces when organic matter is present,” Schmitt said.

An iodine-based product is available for boot baths that remains viable with up to 50% organic matter. Some glutaraldehyde products are effective for boot baths as well, according to Pusey.

Crate and pen cleaning

“The key to cleaning pens is to initially use a cleaner to break down organic matter on the surface,” Pusey said. “Any organic matter must be removed first to get a proper disinfection.”

After using a cleaner and power washing thoroughly under crates and feeders, apply a good quat/glut disinfectant (a mixture of quaternary ammonium and glutaraldehyde), offering a wide spectrum of biocidal activity. Use at label rate and contact times.

In between groups of pigs, biofilms harboring disease and bacteria can grow inside water lines. A hydroperoxide product with peracetic acid will descale and clean the pipes. A chlorine dioxide water treatment system will consistently keep the water lines clean.

“Descaling is important year-round but especially important in hot, humid weather when coccidiosis ramps up,” he added.

After cleaning and disinfecting, allow the room, crates and pens to fully dry before restocking. This allows the desiccation of any remaining bacteria.

Sow washing

“If you are going to the trouble of cleaning and disinfecting farrowing crates, there’s no sense in introducing pigs to dirty sows,” Schmitt said. “Mouth-to-skin contact happens immediately after birth, and washing sows reduces the transfer of E. coli and other enteric pathogens to newborn pigs.”

Iodine-based products are gentle on skin and decrease pathogen transfer to pigs, reducing the incidence of scouring.

Control rodents, insects

Rodent and insect control is critical. “Rodents and insects that inhabit manure pits can act as mechanical vectors to re-infect sows and pigs,” Schmitt said. “Studies have shown that PED and PRRS can both survive in manure slurry for an extended period of time. This is troublesome because rodents may travel back and forth from the manure pit to feeders.”

Rodent control starts with rodenticides used in a rotation of different active ingredients throughout the year. Pusey recommends using two rodenticides with different active ingredients that are anticoagulants and one rodenticide with an active ingredient that is a non-anticoagulant. This rotation will prevent the rodent population from building a resistance to the products.

“For seasonal use, strategize with your veterinarian because some products are better for mice versus rats and vice versa,” Schmitt added.

Cockroach and insect control are also important because they act as mechanical vectors of disease too. They bring disease onto a farm and spread it around.

And last, biosecurity strategies vary greatly between farms depending on the production stage, location and risk tolerance. For help developing a biosecurity program, contact your Four Star Veterinary Service veterinarian.