Use of antibiotics in livestock debated at Bioscience Conference
WORTHINGTON -- Scrutiny over antibiotic use in the livestock industry continues to make headlines across the United States and around the world, making it a timely topic at the 2009 Bioscience Conference Thursday afternoon in Worthington.
The animal health track at the conference gave visitors five perspectives on the use of antibiotics, from the impact it has on animals and humans, to food safety and the environment.
Dr. Steven Dudley, of the Veterinary Medical Center and Prairie Holdings in Worthington, said there is a lot of pending legislation, from restriction of antibiotics to animal welfare issues to environmental concerns.
"My bias as a veterinarian (is) we know antibiotics are an important tool for modern veterinary medicine," said Dudley. "Many disease problems that I encounter on a daily basis require the use of antibiotics."
At the same time, Dudley said antibiotic resistance is a reality.
A couple of the presenters spoke of the time and money it takes to get an antibiotic approved for use in the livestock industry. Often, a decade or more of research is needed and tens of millions of dollars are spent before an antibiotic ends up on the market.
Antibiotics and food safety
"Everyone would agree that food availability and safety within the United States and the world is a critical issue for all consumers," said Dudley.
"Antibiotic usage, as well, is an important part of human and livestock animal health," he said.
Maintaining a safe food supply can be debated on several different fronts, said Dudley, from food shortages to the role of meat producing animals.
"There will be increased population growth," Dudley said, adding that antibiotic usage is important to produce healthy food in the U.S. But as more and more consumers expect antibiotic-free food, animal agriculture will need to address the issue.
The potential for antibiotic restrictions could be a detriment to animal agriculture.
"Recently, we're coming off extremely poor profitability," Dudley said. "Our producers have been losing a lot of money for a lot of months."
Dr. Paul Ruen, with the Fairmont Veterinary Clinic, said about 75 percent of a producer's cost in swine production is feed. With the use of subtherapeutic medications, farmers can realize a 2 percent to 5 percent improvement in average daily gain. By restricting antibiotic use, he said the efficiencies would be lost and it would result in making food more expensive.
Dr. Peter Davies, with the University of Minnesota's Department of Veterinary Population Medicine, said people have debated the use of antibiotics for the past 50 years. Yet, food safety -- particularly in the swine industry -- is "in far better shape" than it once was.
"The use of antimicrobials is a whole lot better today than it was in the past, but consumer perceptions of antimicrobials are a whole lot worse," said Davies.
Livestock producers use antimicrobials for a variety of reasons. Antibiotics are used in disease treatment, control and prevention, while subtherapeutic uses improve production or metabolic efficiency. The U.S. and Canada are still permitted to use antimicrobials to boost production and efficiency, while it is not allowed in the European Union, Japan, Australia and New Zealand, Davies said.
The use of antibiotics is prohibited in Denmark's animal industry, and Davies said animal health has declined and production efficiency has dropped as a result.
Closer to home, Ruen said he works with a swine producer in northern Iowa who has raised antibiotic-free pigs in a confinement barn setting since 2007. The operation consists of about 5,500 sows, with 2,500 head of pigs weaned weekly, on average.
Ruen said the operation experiences an average 8 percent nursery pig death loss, a 7 percent finisher pig death loss and 15 percent are considered cull value pigs. That leaves about 70 percent of the pigs sold at full value on the antibiotic-free market.
"That's not real good," said Ruen, adding that most swine operators expect to see 90 percent of their animals sold at full value. "From an animal welfare standpoint, that's a real loss."
Following the food chain
Satish Gupta, professor of soil, water and climate at the U of M, has spent considerable time researching the impact antibiotic use in livestock has on the environment.
Five years ago, approximately 35 million pounds of antibiotics were produced annually -- 13 percent used for humans and 84 percent used in animal agriculture, Gupta said.
The use of antibiotics in U.S. animal agriculture has led to concerns about the level of antibiotic residue in manure and the potential for that residue to get into the soil and water supply.
Gupta conducted research at the Southwest Research and Outreach Center in Lamberton, as well as research sites in Staples and Lancaster, Wis., testing soils that had received applications of swine manure, turkey manure and urea.
"There is some potential for transport of antibiotics both through leaching and through runoff from manure-applied soils," said Gupta, adding that the majority of the antibiotics dissolved in the soil.
Increased concentration of soil-applied manure, however, shows an increased uptake of antibiotics by the plants. Gupta said while antibiotic levels in plants appears minimal, there are some implications on organic vegetable growers who use manure as fertilizer.
In addition to the concerns of antibiotic levels in plants, Gupta said producers will need to be mindful of applying manure on erodible soils.
"If you have erosion of the soil, you're going to want to control it because the soil can be carrying antibiotics," he said.
In addition to the animal health presentation Thursday afternoon, the Bioscience Conference also included a series of meetings on wind energy, biofuels and biomass feed stocks.
Today's schedule includes keynote speaker Steven Burrill, CEO of Burrill & Co., at 8 a.m., followed by a presentation on talent development for ag-based biosciences. The Worthington Middle School Science Club will also give presentations beginning at 10 a.m.