Pig care and pig health have always been at the top of every producer’s mind. That hasn’t changed at all with the new regulations regarding antibiotic use in livestock; just the mode of achieving healthy pigs may have changed.
Producers can still use antibiotics for the treatment, prevention and control of health issues, if those drugs are not medically important in human medicine. If a producer wishes to treat an animal with an antibiotic that is medically important in human medicine, he or she must do so under the strict guidance of a licensed veterinarian.
Russ Daly, South Dakota Extension veterinarian, says his phone has been ringing off the hook with concerns and questions on veterinary feed directives and antibiotics. “This is something that’s on the front of your minds,” Daly says of producers’ concerns.
With all this concern about the potential of antibiotic use in livestock contributing to antibiotic resistance in humans, livestock producers are being forced to take a hard look at their herd health approach.
“I will say this right up front,” says Liz Wagstrom, National Pork Producers Council chief veterinarian. “Antibiotic resistance in humans is a real phenomenon. In hospitals there are people who cannot be successfully treated because of resistant bacteria.”
Wagstrom takes exception with a graphic put out by the Centers for Disease Control and Prevention that shows antibiotics being fed to livestock at the top “and then at the bottom, a person dies. … Now I don’t think it’s that direct of a relationship, but I do believe that we have some share of responsibility for antibiotic resistance in human medicine. Probably if you look at resistant food-borne salmonella, it’s pretty hard to say that’s because of antibiotics use in humans.”
Wagstrom feels the contribution that the U.S. livestock industry makes to antibiotic resistance in human medicine is pretty small, “but it’s our responsibility to take control of what we can handle, what’s our responsibility, and minimize that contribution as much as we can.”
Whether that connection is perceived or real, producers are being forced by retailers who in turn are being forced by consumer groups to reduce, or eliminate entirely, the amount of antibiotics being used to produce the food on their shelves or menus.
“Guidance 213 was a watershed moment,” she says. “We got rid of growth-promotion medically important antibiotics, and we’ve got the other uses that fall under the veterinary feed directive or prescription. Our advocacy groups are not going to stop with that success. They are very focused on routine prevention uses of antibiotics.” The National Resources Defense Council and others petitioned the Food and Drug Administration to ban all prevention uses of antibiotics. Wagstrom does not expect this petition to go too far, but she says the FDA currently does have the Federal Registry notice asking for information about prevention uses, why they’re used and how long they’re used. “Right now their focus is on prevention uses of antibiotics that do not have a duration on the label,” she says.
Though Guidance 213 went into effect Jan. 1, “that was a big moment for us, but that’s not the last of the moments we’re going to see on antibiotic use,” she says.
Probiotics have been thrown around as possibly replacing antibiotics in a producer’s health care toolbox. Are probiotics a viable option to replace antibiotics? “No” is the short answer given by Wagstrom. “If you look at what a true replacement needs to do, there is no one replacement for antibiotics.”
Wagstrom presents a list of criteria needed to truly replace an antibiotic. A true replacement must have:
■ consistent performance
■ no side effects in treated animals
■ no residues in food
■ no development of bacterial resistance
■ ease of administration, stable in feed/water and the gastrointestinal tract
■ no environmental impact
■ ability to kill or inhibit growth of pathogenic bacteria
■ ability to enhance resistance to disease
■ ability to improve feed efficiency or promote growth
■ no negative interactions with other feed additives
“Replacements can do some of these, but not all,” Wagstrom says. “There are a lot things that a lot of these alternatives can do, but to lump them together and have them be that silver bullet, that’s probably not so easy.”
Wagstrom stresses that the more appropriate answer to the question of whether probiotics can replace antibiotics probably is “That depends. … it depends on what aspect of the antibiotic that you are trying to replace, and what other conditions exist on your farm and what disease situations exist on your farm.”
Other aspects producers need to consider for effectiveness of alternative treatments are the current health situation; what the farm’s environment is like — old facilities that are hard to manage, new facilities where you can keep air and heat under control; your management; whether you can fill the barn with weaned pigs in three days versus three weeks. “You also need to look your herd’s genetics,” she says, “and there are a lot of other etceteras” to be considered.
Wagstrom says these factors also play into the effectiveness of antibiotics, so producers need to be conscious of them regardless of the mode of animal health protocols being used on the farm.
To find an adequate antibiotic replacement, producers and the entire swine industry need to clearly define what a proper alternative can do to:
■ enhance production
■ reduce the need for antibiotics
■ prevent disease
■ improve general health
■ treat disease
■ give symptomatic relief
“You see claims out there that products improve gut health, improving integrity of the overall gut, and improving overall health,” Wagstrom says. She says there are not a lot of products available for disease treatment. “What you see us do most in the pig industry for disease treatment is symptomatic therapy, like we’ll put an aspirin in a water medicator to make the animals more comfortable.”
As producers venture into some of these alternatives for their animals, Wagstrom reminds that most of the products do not have FDA-approved claims, “so you don’t have a label that says ‘This product has been evaluated by the FDA,’ but they have seen data that makes them comfortable enough to say that this product improves nutritional efficiency, growth promotion or prevents disease. Most of them have been considered GRAS, or generally regarded as safe. So if it’s a feed additive, it’s not going to hurt anything, but the claims themselves have not gone through FDA review.”
Time and money are more than likely the biggest reasons that companies do not put their products through FDA review, as Wagstrom has been told that the licensing of a therapeutic drug costs tens of millions of dollars and probably takes seven to 10 or more years.
Wagstrom says ionophore use has been picking up with less than 5% in U.S. nurseries and 10% to 20% in finishing barns. High levels of inorganic copper and zinc have shown higher use with reasonable results in nursery (60%-70% Cu, over 90% Zn) and finishing herds (60%-70% Cu and 5%-10% Zn). “In Europe, they are talking about banning zinc due to environmental concerns, but that’s probably what allowed the European Union to get rid of antibiotic use.”
Just as companies look at the cost and time to put products through FDA review, producers need to take a look at their operations to see if the implementation of feed additives will be economically feasible. Wagstrom suggests producers measure their net return by looking at the consistency of the response; whether the response is measurable; whether there are interactions with other feed additives; and the cost versus risk of response. Project your return on investment to equate what is enough to justify the alternative given all the above.
Solid production practices can reduce the need for antibiotics altogether, and each of the following work together:
Vaccination. What should you use, and what is the best timing?
Hygiene and biosecurity. “With PEDV [porcine epidemic diarrhea virus] we learned a big lesson, and we’re learning it again with Seneca Valley,” she says. “We think we have great biosecurity, but we found a lot of holes. So that’s something we can all take a look at.”
Pig flow. “If you don’t have single-sourced pigs coming in pretty tightly grouped on age, you’re going to have some challenges.”
Wean age. “In Denmark, they actually have a law that you can’t wean before 28 days,” Wagstrom says, and many are going to 30 to 35 days of age because they aren’t able to use the antibiotics as they would like.
Diet. “You need to work with your nutritionist to make sure you’ve got your diets maximized.
“Then, if you get all of those in place, and are happy with those,” Wagstrom says, “how does that contribute to the response to those products?”
Take care of your house
As Wagstrom says, Guidance 213 is more than likely only the beginning of oversight of the U.S. livestock industry and animal-care products.
Fingers have commonly been pointed at the livestock industry as a cause of humans developing antibiotic-resistant bacteria in their bodies, even though Wagstrom says that relationship is in less than 10% of the cases. “Regardless of what that number is, 10%, 8% or 1%, we do have some share of responsibility in human antibiotic resistance,” she says. “… we need to minimize that contribution as much as possible.”
Wagstrom made a presentation at the South Dakota Pork Congress in early January.