Antibiotics in agriculture: What is their place?

By Dr. Al Schultz Since they became a huge part of human medicine in the 1940s, antibiotics have saved millions of lives, but we are getting increasingly worried because they don’t work as well as they used to.  Although the pharmaceutical companies are developing new strategies to address this issue,  the man-versus-bacteria war continues onward. Antibiotic resistance emerges through genetic mutation of the bacteria.  In any given bacterial population, maybe 99.999 percent of the bacteria are killed by an antibiotic.  But that one in a million that survives because of its ability to adapt may keep multiplying.  Many generations later, that one bacterium has grown to a population capable of surviving the same antibiotic that once worked on its ancestors, and also of sufficient numbers to cause some serious disease challenges.  This population is also likely to be resistant to other antibiotics that have a similar mode of action. It seems reasonable then to make the short leap to, “If antibiotic overuse in humans causes a loss in potency over time, so then antibiotic use in livestock is just as much a problem.”  The livestock industry has come under attack for its continued use of antibiotics.  At the same time, the FDA has been pressured because it has not banned the antibiotics used in livestock production. In many cases, both sides of the battle are backed by some science even though their positions may be diametrically opposite.  Truthfully, at the end of the day (or maybe decade), public policy and livestock management practices may be more influenced by the court of public opinion than by science. Here’s the issue as I see it:

• Antibiotic resistance is an emotional issue. Plenty of made-for-TV stories tell a tale of someone dying because an infection was resistant to antibiotics.  But many studies show no link between antibiotics used in agriculture and resistance in humans.  This doesn’t mean we shouldn’t err on the side of caution, but anyone advocating for a ban on the use of antibiotics in livestock and expecting that step to solve the resistance issue is either uninformed or overly optimistic.
• Livestock farmers have a social responsibility to produce meat, milk, and eggs with concern for animal welfare, the environment, the health of workers and food customers, and the quality of the products they produce.  Livestock and birds get sick; that’s nature.  Withholding antibiotics from treating a disease outbreak because we need to “protect” antibiotics at any cost is irresponsible.
• Newer antibiotics that are deemed “not useful for human medicine” have been approved for the livestock industry. In contrast, antibiotics that are approved for human use are withheld from the agriculture market.  Thus, resistance to animal antibiotics will develop in animals and resistance to human antibiotics will develop in humans.  They won’t crossover.
• The amount of antibiotics used per animal is not related to the size of the farm. If you object to larger farms, do so because of nostalgia or other reasons.  Antibiotic use is not a relevant reason to block the growth of our well managed farms.
• Treating a whole herd or flock versus individual animals is done for several reasons: (1) Treatment of the whole group via feed or water (versus penning or restraining) reduces animal stress. (2) Group dosing reduces the risk of handling-related animal injuries, such as bruises, broken bones or broken needles. (3) Group dosing results in less chance of injury to employees handling large, stubborn and panicky animals.
• The use of antibiotics as a means to improve performance in situations where there is no specific disease challenge has reduced substantially over the years. Scientific evidence shows the practice of low-level antibiotic use may not be a risk, but the court of public opinion probably doesn’t care about the science on this one.  I think the FDA has it right with the push to voluntarily get a reduction in the use of “medically important antimicrobial drugs” in situations where performance enhancement is the only goal.  Again, keep in mind that many compounds used in livestock and poultry have no use whatsoever in human medicine.
• The food consumer is our customer. As food retailers point out – we can stand on principle and lose the customer.  At some point, the marketing aspect becomes part of the equation.  For those of us driven by science, that can be hard to accept.
• Don’t forget the rule of unintended consequences. After Denmark banned low-level antibiotics, the use of therapeutic antibiotics increased by 30 percent.  Making a knee-jerk reaction to change one outcome may result in unforeseen problems.

Simple politically expedient fixes aren’t going to lead us to answers, but neither is a total ignoring of what we see happening around us.  Some measured reaction – maybe something close to the FDA’s proposal in its recent guidance documents – offers the best opportunity to make medical progress as well as maintained trust of our customers for meat, milk, and eggs in the face of a highly emotional debate. Click here for Schultz’s full whitepaper document titled “Antibiotics in agriculture:  What is their place?” About the author: Dr. Al Schultz is vice president of Vita Plus and has been an employee owner for more than 35 years.  Schultz grew up in eastern Wisconsin on a registered Holstein dairy farm. One of his “claims to fame” is the family showing of the Grand Champion Holstein cow at the 1968 World Dairy Expo. He has earned all of his degrees in dairy science from the University of Wisconsin–Madison. Currently, Schultz oversees activities related to product formulation, quality control and regulatory issues. In addition, he works closely with the dairy team and has corporate responsibilities. He lives with his wife in Verona, Wis. His two grown children and their spouses include a diverse mix of a teacher, lawyer, airline pilot and doctor.