Attrition has drawn increased attention in the pork production business, and well it should according to John Deen, DVM, University of Minnesota. He says it can cost the U.S. pork industry up to $1.2 billion annually in lost revenues.

Attrition includes dead, culled and lightweight pigs — essentially any pig that falls outside of production and marketing parameters. Deen says it creates huge inefficiencies on farms, noting that 30 percent to 35 percent of pigs born never make it to an acceptable market weight.

“How many businesses would accept that level of attrition?” he asks.

A National Attrition Survey also identified that nearly one in three weaned pigs fail to reach full-market value. The survey involved operations marketing 1,500 head annually to those marketing more than 1 million hogs.

Respondents revealed a nursery-to-market attrition rate of 31.1 percent. That was comprised of 5.5 percent dead, 4.6 percent culled and 21 percent lightweight hogs.

Producers said attrition costs them an average of $39.21 per affected pig or $12.19 per pig placed. Per-pig attrition costs broke out as $4.25 for dead, $2.56 for culled and $5.38 for lightweight hogs. In a 1,000-head grow/finish building, those losses would add up to $12,193.

Deen acknowledges that eliminating attrition isn’t practical, but says producers should focus on meeting these benchmarks:

  • 6 percent to 8 percent for pre-weaning mortality.
  • 2 percent mortality in the nursery.
  • 2 percent mortality in the grow/-finish phase.
  • 3 percent for culled animals.
  • 10 percent for lightweight pigs in the grow/finish phase.

  “Producers should view attrition as an opportunity for improvement,” says Deen. “This is critical if we, as an industry, want to focus on increasing our output value, rather than continue to just look at inputs and production costs.”

Herd-health issues, which create poor-doing pigs or even death are the driving forces in attrition. This is particularly true of enteric disease. Deen says disease control is the key to reducing or preventing attrition. For example, therapeutic drug use in the case of enteric disease can help reduce pathogen shedding, which limits disease spread to other hogs.

“In fact, we should be more aggressive with therapeutic programs to stop shedding and disease transmission early. That works best on the animals at most risk, so the small pig is more likely to benefit from therapy than a big pig, especially early in the disease process,” says Deen.

He points to production, financial, herd-health and packers’ records as helpful tools in quantifying attrition and uncovering its causes. “Producers should measure attrition, pinpoint its causes and implement the most appropriate intervention strategies,” says Deen.

“There are specifications to be met at each production stage, whether it’s breeding, farrowing, nursery or grow/finish,” says Deen. “We have to identify criteria for the minimum acceptable weight for pigs to move to the next stage.”

That likely means sitting down with your veterinarian, other consultants and staff to find areas to take action. Also, to get an accurate grasp of attrition costs you should consider opportunity costs because they capture the difference between actual revenue and potential revenue.

“The industry is leaving a lot of money on the table,” says Deen. 

Editor’s note: Web-based worksheets found at can help you evaluate attrition rates in your herd.