Large reductions in the use of medically important antibiotics for broilers and turkeys have been taking place in the United States over the past five years.
A study released by Mindwalk Consulting Group, which looked at datasets representing up to 93% of the annual US broiler crop and 82% of turkey production, found a substantial usage reduction between 2013 and 2017.
The report documents substantial reductions in the use of most medically important antimicrobials in broiler production, regardless of route of administration.
The reductions are likely to be the result of tougher guidelines from the US Food and Drug Administration and changes to the veterinary feed directive.
Among the key findings for broilers were:
• In-feed virginiamycin use decreased by approximately 60% between 2013 and 2017
• In-feed tetracycline use decreased by approximately 95% during the same period
• There were no remaining approved uses of in-feed tylosin in broilers, meaning in-feed tylosin use went to zero in 2017
• The approximate percentage of broiler chicks placed that received hatchery antimicrobials decreased from 93% in 2013 to 17% in 2017.
• Hatchery gentamicin use in broiler chicks decreased approximately 74% between 2013 and 2017
• Medically important water-soluble antimicrobial use also decreased substantially with reductions seen in use of penicillin (21%), tetracycline (47%), lincomycin (28%), sulphonamide (72%) and tylosin (46%).
The study showed there was a shift to antimicrobials that are not considered medically important, such as in-feed bacitracin, which has been commonly used to prevent necrotic enteritis. In-feed avilamycin use also increased in 2017.
It found that several key diseases were targeted by antimicrobial administration – necrotic enteritis, colibacillosis and gangrenous dermatitis.
Among the key findings for turkeys were:
• A fall in turkey poults placed that received hatchery antimicrobials from 96% in 2013 to 41% in 2017
• Hatchery gentamicin use in turkey poults fell by 43% in the same period
• In-feed tetracycline use decreased by 67%
• No remaining approved uses of virginiamycin or in-feed tylosin in turkeys by 2017
• Water soluble penicillin, tetracycline, lincomycin , neomycin, erythromycin and tylosin fell by 42%, 28%, 46%, 49%, 65% and 275%.
Project lead Randall Singer, professor of epidemiology at the University of Minnesota, told industry sources that a lot of antimicrobials had been removed from the production system, particularly from the hatchery.
“In the 2013 data, over 90% of these chicks and poults were getting a hatchery antimicrobial, meaning a critically important drug, that’s a lot of treated animals. It’s not always easy to pull those antimicrobials out of the hatchery, because they do serve a purpose, and so it required the companies that did make those changes to also have to make changes within the hatchery and within their houses.”