The US pork industry has a good track record for using antibiotics responsibly, but how should it be graded for its efforts? By volume? Types of antibiotics used? Resistance trends?

“We don’t really have a perfect report card for antibiotic resistance,” Peter Davies, BVSc, PhD, professor in the department of veterinary population medicine, University of Minnesota, told Pig Health Today.

Having spent his career researching and evaluating antibiotic use and potential resistance, he believes all of the prescribing professions - human and animal - have a responsibility to review how they use antibiotics and to use them more effectively to maximum medical benefit.

For pork production, Davies prefers to focus on optimising use, which he defines as using antibiotics for a targeted purpose. More precisely, that means using antibiotics strategically to manage identifiable health risks within an animal’s lifecycle, as well as animal well-being and food-safety considerations, he noted.

Making progress

Davies said pork producers and swine veterinarians have embraced FDA’s expanded veterinary feed directive (VFD), which took effect Jan. 1, 2017, and required a veterinary-client-patient relationship (VCPR) before using any medications the agency considers medically important to humans.

Since then, FDA reported a 33 percent decline in the volume of medically important antibiotics used in food-animal production in 2017, which is on top of a 43 percent reduction in 2016. The pork sector recorded a 35 percent drop in volume for 2017.

Reductions in volume of medically important antibiotics reflects the impact of the expanded VFD, Davies said, but he cautioned that while volume might be the easiest number to obtain, it should not be the sole metric for grading the pork industry’s approach to responsible antibiotic use. He’s nevertheless encouraged by changes in the ways antibiotics are obtained and used.

“We have more veterinary oversight,” Davies said, adding that this has led to more effective antibiotic use and, perhaps more importantly, helped eliminate unnecessary use.

“It’s the responsibility on the veterinary side to make the judgement to use as little [medication] as possible to keep the balance between animal-health outcomes and risks,” he said.

Other factors also affect antibiotic usage. For example, Davies cited a long history of advancements in swine housing and environments, pig flows, biosecurity, vaccines and numerous other management factors that have helped reduce disease pressure and the need for antibiotics to control primary or secondary bacterial infections.

Davies also emphasized that reduced antibiotic use is not a simple end-point. “Even in the best possible circumstances, animals will get sick,” he said, which is why it goes back to the VCPR to ensure responsible use and animal well-being.

Antibiotic-free pork limitations

Still, there is a rush by some to remove all antibiotics from food-animal production as a response to antibiotic-resistance concerns, to which Davies offers caution.

“On the pig side, the goal that we would produce pigs without [using] antibiotics is a fairly unrealistic one,” he said.

For example, the antibiotic-free pathway for the broiler industry is different because the hatch/birth environment and exposure are substantially different - an egg versus through a birth canal and the back of a sow. Also, broilers are typically raised for six to nine weeks, whereas pigs are marketed at about 6 months.

“The biological risks are very different,” he noted. “We will see some expansion of the niche raised-without-antibiotics production. But in terms of the ability to continue to feed the world, it’s hard for me to see that antibiotic-free production will be a substantial component of the pork market internationally.”

Overall, Davies said the pork industry has done a commendable job over the last 30 years of using antibiotics responsibly and pointed to the fact that antibiotic residues have essentially disappeared.

“I still think we have a lot to learn about optimizing our antibiotic use,” Davies added. But he is confident the pork sector will continue to move in that direction.