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.



Slaughter checks pinpoint subclinical disease like atrophic rhinitis

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Slaughter checks performed at a packing plant are an underutilized tool for diagnosing subclinical disease, says Brad Schmitt, DVM, Four Star Veterinary Service, Rushville, Indiana.

“We as swine veterinarians do a really good job of recognizing and treating clinical diseases that may be causing an obvious morbidity and mortality in the population,” Schmitt said. “I think we’ve got room to grow in recognizing subclinical issues that may not jump out at us, but they’re still there and affecting finishing performance.”

Atrophic rhinitis shows up

One disease Schmitt sees frequently on slaughter checks is atrophic rhinitis, a disease that was easily spotted by twisted snouts in the past.

“Now it’s become more of a subclinical issue where you might not see it in your live pigs, but essentially, it’s a damage to the filter that’s removing particulate going into the lungs,” he explained. “It’s predisposing those pigs to more pneumonia and respiratory issues.”

During a slaughter check, Schmitt tries to observe at least a couple of loads of hogs. Standing on the processing line, he is able to scan the viscera, cut snouts and determine the types of lesions in pigs. Other pathogens and disease processes that might be detected during a slaughter check include Mycoplasma hyopneumoniae, Mycoplasma hyorhinis and roundworm infestation. These often go undetected while still affecting growth and efficiency.

“It gives us a good idea of what’s going on with the overall population rather than just a few sick pigs that you might normally do a post-mortem on,” he said.

Setting up slaughter checks

Slaughter checks must be scheduled ahead of time with the processor. Schmitt said some packers are more willing to work with veterinarians than others, and Covid-19 fears will certainly play into this as well.

“You are right there on the line interacting with the USDA veterinarian and other inspectors,” he explained. “Sometimes it is difficult to get in there without disrupting a production line.”

The extra effort to organize and perform slaughter checks is well worth it, according to Schmitt.

“I think it’s a very underutilized tool,” he said. “[Because] we’ve had ractopamine removed from our toolbox to help promote performance, I think we need to focus on other ways to do so. And this is one of those ways to fine-tune the health of our animals. Without knowing what kind of subclinical issues the pigs may have, they’re difficult to improve upon.

“We need to do a better job of promoting [slaughter checks] and making them a routine occurrence,” Schmitt concluded.

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.



Bull calves: Maintaining health and consumer confidence

By Brad Schmitt, DVM, Four Star Veterinary Service, LLC

Brad Schmitt, DVM


Where there are dairies, there will undoubtedly be bull calves. It’s what we make of those calves that differentiates progressive dairy farmers from the rest. In the past, bull calves were seen as an inevitable byproduct of the dairying process, but that ideology has since evolved. Dairy bulls now go on to be reared for either high quality veal or “dairy beef,” which there is great consumer demand.

To ensure that this demand continues, we need to remain vigilant in producing a safe and healthy product that consumers can trust. This requires health maintenance from birth to harvest, as well as judicious use of antibiotics in order to maintain consumer confidence.

Maintaining health

Whether a heifer or bull, the calf is contributing to our food supply and should be given every possible opportunity to thrive. From the time the calf hits the ground, to when it leaves the dairy farm is arguably the most critical period in terms of setting that calf up for a lifetime of health and productivity. Regardless of sex, calves should be treated with identical husbandry practices. Vaccination strategies will vary, but basic husbandry needs to be the same. Here are a few non-negotiables:

    • Colostrum

Timely colostrum intake is crucial for immune development, as calves are born with naïve immune systems. Unless administering oral vaccines at birth, colostrum or quality colostrum replacer needs to be the first thing that enters the stomach. A good rule of thumb is to feed at least 2 quarts by 2 hours of age, followed by another 2 quarts by 6 hours. This allows for adequate absorption of maternal antibodies, which will protect the calf in the short term and set the stage for long-term immunity. Ensuring early colostrum intake prevents Failure of Passive Transfer of Immunity (FPTI), thereby greatly reducing treatments, morbidity, and mortality after leaving the dairy.

    • Navel care

It’s important that navels are dipped shortly after birth, creating a barrier between the umbilicus and any environmental pathogens. Use of a 7% iodine tincture or chlorhexidine/alcohol product disinfects the navel and accelerates drying of the cord to prevent future infection; don’t hesitate to repeat this action if necessary. By dipping, rather than spraying, we avoid the “shadowing effect” and make certain that the entire navel is coated. Proper navel care effectively reduces the incidence of septicemia, septic arthritis, and umbilical hernias.

    • Suitable environment

The first week of life is stressful enough without having to battle the elements. Minimizing environmental stress by providing a warm, dry place for the calf to lay goes a long way towards health and welfare.  Shade, bedding, wind blocks, etc. should be strategically used for both heifers and bulls. Keep in mind that the thermoneutral zone for a newborn calf is between 55-70 oF; any variance from this, and they’re expending valuable energy to heat or cool themselves. Two areas of focus are bedding and ventilation management. By maintaining clean, dry bedding, navel infections are greatly reduced and significantly less body heat is lost through conduction. Appropriate ventilation directly affects respiratory health; by getting down to the calf’s level, we can determine if air exchange and ammonia levels are within acceptable limits.

Maintaining consumer confidence

It will come as no surprise that plant-based protein has continued to gain market share in recent years. The Good Food Institute has cited a yearly increase in plant-based “meat” sales of about 18% since 2017. As more options become available to consumers, we in the animal agriculture industry must continue working to instill confidence in our rearing practices and final meat products. This boils down to upholding welfare standards and avoiding drug residues, two topics that should not be taken lightly.

    • Welfare

If you see something, say something. The vast majority of producers take excellent care of their animals, practicing proper welfare with pride. Unfortunately, a few bad apples remain and give the industry a black eye from time to time. When willful acts of abuse or neglect are detected, it’s important that we address them immediately to prevent future incidents.

See it? Stop it! is a resource to share with your employees. To confidentially report concerns, call the See it? Stop it! hotline at 833-207-7457 or email:

    • Drug residues

Labeling meat as “Antibiotic-Free” and “No Antibiotics Ever” has become a popular marketing tool because it conveys a sense of safety to the consumer. We in the animal agriculture industry know well that all meat going into the food supply is free of appreciable amounts of antibiotics, as long as appropriate withdrawal times are observed. Alarmingly, drug residues are still commonly detected in cull dairy cows and bob veal, as referenced by the 2019 USDA National Residue Program. It’s our responsibility to prevent drug residues, so that we may continue using these valuable tools in the future.

The United States FDA outlines a T.A.L.K. method for preventing drug residues.

T: Talk with your veterinarian before giving any drug to your animals.

A: Ask if the drug is FDA-approved for use in food-producing animals. Extra-label drug use should only occur under the order of a veterinarian, who is responsible for establishing an appropriate withdrawal time.

L: Look at the label. Know the drug you are giving and the approved dosage regimen. This includes dose, frequency, duration, and route of administration.

K: Keep complete treatment records. It’s important to know which animals were treated, what drug was used, dosage regimen, why they were treated, and when the specified withdrawal time allows those animals to be harvested.


These basic health and welfare routines are required by both Veal Quality Assurance (VQA) and Beef Quality Assurance and are expected of every producer. Proper care and attention early in the calf’s life is vital for success after leaving the dairy, whether it goes on to become a replacement heifer, dairy beef, or veal. By producing healthy animals in a responsible manner, we can continue to secure our place in the protein market.

The Healthy Veal Calves Start at the Dairy on Day 1 infographic is available by clicking here.

More information on dairy calf care and VQA resources are available on


This article, Bull Calves: Maintaining Health and Consumer Confidence, is provided as part of the Veal quality Assurance Program outreach efforts funded by the Beef Checkoff.