Despite recent efforts by health experts, doctors, and the Food and Drug Administration to pull the meat industry away from its heavy use of antimicrobials, livestock producers seem to have dug in their heels.

From 2009 to 2014, the amount of antimicrobials sold and distributed for use in livestock increased by 22 percent, according to an FDA report released Thursday. Of the antimicrobials sold in 2014, 62 percent were related to drugs used in human health, also called medically important. From 2009 to 2014, sale and distribution of medically important antimicrobials used on farms also jumped—an increase of 23 percent.

That brings the 2014 total of antimicrobials sold for US livestock to 15,358,210 kilograms, including 9,475,989 kilograms of medically important drugs, according to the report.

In 2013, researchers estimated that agriculture and aquaculture take in about 80 percent of all antibiotics (which are technically a subset of antimicrobials, but they are sometimes used synonymously) sold in the US.

The new data comes amid calls for responsible use of antimicrobials and antibiotics—in clinics as well as farms. Last month, the American Academy of Pediatrics called on livestock producers to curb overuse of drugs on farms. Much of the tonnage of drugs go to illness prevention on factory farms rather than treatments for sick animals. And producers sometimes use the drugs because they help animals fatten up. Such overuse, the doctors argued, is fueling the development of antimicrobial resistance among microbes, which in turn can cause difficult-to-treat infections in people , particularly vulnerable children.

In 2013, the FDA introduced voluntary guidelines to phase out using antimicrobials to boost animal growth, cut back on other uses, and consult veterinarians when antimicrobials are used. (Unlike antibiotics approved for human use, many antimicrobials used in animals are sold over the counter).

But the FDA’s guidelines appear to have had little to no impact so far. Sale of animal antimicrobials increased by four percent from 2013 to 2014, while use of medically important antimicrobials increased by three percent, according to the new report.

In a statement, Rep. Louise Slaughter (D-NY) said, “This report demonstrates what I have been saying for years: that FDA’s policies have been toothless in the face of the continued, widespread misuse of life-saving antibiotics in factory farms... The increased use of antibiotics over the last year is particularly disgraceful.”

The Congresswoman, a microbiologist by training, called on the FDA to immediately prohibit the use of medically important antimicrobials on farms.

In an interview with Reuters, Ron Phillips, spokesman for the Animal Health Institute, defended the meat industry, saying, "Sales does not equal use and use is not the same thing as resistance." The Animal Health Institute represents animal drug companies.