Concerns about what do when depopulation of swine herds becomes necessary came to the forefront after meat processing plants' closures due to COVID-19 created market issues. 

As consequences from the ongoing COVID-19 pandemic started to hit agriculture full force, Wisconsin dairy farmers made headlines for dumping milk due to supply chain issues.

Across the state’s western border, though, Iowa and Minnesota farmers were making headlines for another supply-chain issue: Due to disruptions in the pork processing industry, farmers were suddenly faced with a large surplus of unmarketable hogs and left with the difficult decision of whether and how to start euthanizing parts of their herds.

Harvest capacity has improved since the beginning of the pandemic, but the National Pork Producers Council has estimated that producers will lose over $5 billion collectively this year, not including lost value from pigs euthanized or donated or the costs associated with depopulation and disposal.

The pain was felt keenly in Iowa and Minnesota, who at 25.2 million head and 9.6 million head, respectively, in the period of March through May held the nation’s largest hog inventories, according to a United States Department of Agriculture National Agricultural Statistics Service inventory report.

Faced with backlogs of thousands of animals, some swine farmers did ultimately make the hard decision to begin euthanizing animals.

The kind of widespread depopulation that happened in Iowa and Minnesota didn’t show up in Wisconsin, said Jeff Swenson, livestock and meat specialist at the Wisconsin Department of Agriculture, Trade and Consumer Protection during a virtual Badger Swine Symposium on Nov. 5.

Though Wisconsin was able to keep the meat moving relatively well and state-inspected facilities are doing a lot, Swenson said, plants are still stretched thin and many meat processors are booked out until the first quarter of 2022, making it hard to have any unscheduled butchering done in 2021.

While COVID-19 was an unexpected blow to the swine industry, it’s far from the only circumstance that could prompt depopulation, though. In addition to market disruptions, a number of categories of disease, toxic or radiologic exposure, or natural disasters are causes that may necessitate depopulation, according to recommendations from the American Association of Swine Veterinarians.

Basic planning and taking advantage of available resources can help prepare for such events and be of assistance in case of an emergency.

It’s hard to plan for depopulation if a farmer doesn’t have data, such as where the pigs are and what sizes they are, readily available because some methods of depopulation will be more or less efficient than others, said Becki Slater, emergency response coordinator for DATCP’s Division of Animal Health.

There isn’t a one-size-fits-all recommended approach to depopulation.

Some methods won’t be practical for mass numbers or different ages of pigs, said Julie McGwin, who manages the DATCP swine program. Other factors when selecting a method can include human safety and pigs’ mobility.

Decisions will vary premise to premise, Slater said, and professionals can give recommendations for depopulation and disposal based on a specific herd and the circumstances being faced.

Depending on which factors are in effect when a decision is made, preferred methods of depopulation include gunshot, penetrating or non-penetrating captive bolts, electrocution, manual blunt force trauma, inhalation methods such as carbon dioxide and non-inhalation methods, McGwin said, citing information primarily from the American Veterinary Medical Association.

Other options, such as ventilation shutdown and sodium nitrite, are less ideal but are permitted in constrained circumstances, McGwin said.

Humane handling before and during depopulation; rapid loss of consciousness; and minimal, if any, anxiety, pain or distress before loss of consciousness are goals to strive for when making decisions about depopulation, McGwin said.

The decisions made to try to achieve those goals when depopulation is a necessity won’t necessarily be clear cut, but knowing which options are available and where to get advice could be the place to start.