Producers need antibiotics to keep livestock disease-free before it enters the food chain, industry representatives told a House of Commons committee Tuesday.

Despite concerns antibiotics use in livestock can increase drug resistance in the people who eat the meat, the medication is necessary to prevent diseases from hitting and spreading among groups of animals, industry groups said.

Reynold Bergen, science director for the Canadian Cattlemen's Association, says producers use antibiotics carefully because they're expensive and because they rely on them to be effective.

"When anti-microbial resistance develops the product isn't effective anymore. And losing the effectiveness of those tools is something we can't afford to have happen," he said.

Mike Dungate, head of the Chicken Farmers of Canada, says most antibiotics administered to livestock are prescribed by veterinarians.

"We have a real complex balancing act between animal health, food safety and animal welfare. We treat our flocks with the minimum amount of antibiotics that we need to maintain those three things," he said.

Disagreement on link

However, the industry groups and consumer advocates clashed over whether antibiotic resistance in humans is linked to antibiotic use in the animals people eat.

Rick Smith, head of consumer advocacy group Environmental Defence, says Canada doesn't collect the data that would allow researchers to study the possible link. He says the industry should track which drugs are used and where they're used.

"Then we can look at what impact that's having on human health," Smith said.

"It's clear that there are important drugs used in human medicine that are used in a widespread way in livestock agriculture and that needs to be better controlled," he added.

Dungate agreed on the need for more research.

"We do need, though, more investigation into what is this causal link between use on a human side and use on an animal side, and resistance in humans," Dungate said.

The committee is looking at whether giving antibiotics to the animals Canadians eat makes bacteria more resistant to the drugs used to treat human health problems.

NDP MP Megan Leslie said she hopes the committee can find out who's ultimately responsible for watching over the antibiotic resistance.

"It seems that there are a lot of silos here and really it's the health of Canadians at stake. So someone needs to take responsibility here, whether it's [the Public Health Agency of Canada] or Health Canada, there needs to be better monitoring, there needs to be better regulations about the fact there are antibiotics going into livestock when they're not even sick."

"Why are we pumping these animals full of antibiotics — so they just grow faster?"

Resistance in chicken

A special investigation by CBC's Marketplace tested 100 raw chicken samples from Montreal, Toronto and Vancouver.

All of the bacteria uncovered during the Marketplace sampling were resistant to at least one antibiotic. Some of the bacteria found were resistant to eight different types of antibiotics.

The sampling results revealed that common illness-causing bacteria had turned into superbugs that are increasingly resistant to the usual treatment protocols.

Resistance grows

How did these bacteria become superbugs? Doctors and scientists told Marketplace co-host Erica Johnson that chicken farmers are overusing antibiotics - routinely giving healthy flocks doses of amoxicillin, tetracycline, erythromycin and ceftiofur to prevent disease and to make the chickens grow bigger, faster.

Industry groups say they use antibiotics judiciously.

But it isn't clear what the industry means by "judicious use." The industry won't say how much antibiotic use is occurring, saying it doesn't keep track. The federal government doesn't track antibiotic use by farmers, and, unlike in Europe, there are no limits on the use of antibiotics in the feed and water given to chickens.

While thorough cooking kills bacteria - including superbugs - most contamination happens before the chicken is cooked through improper handling. If there's contamination by superbugs, the worry is that consumers could ingest illness-causing bugs that are then resistant to much of the available spectrum of traditional antibiotic therapy.