The data, released last month (May 2019), gave the latest benchmark for swine sites and cattle rearers on antimicrobial use in US feedlots and swine operations.
Based on two detailed national studies conducted in 2016, the analysis showed how and why antimicrobials were used in feedlots and swine operations, before a major policy change took effect on 1 January 2017, which limited their use to promote animal growth. Veterinary oversight is now required when using medically important antimicrobials in animal feed or water.
Kelly Fogarty, of the United States Cattlemen’s Association, told GlobalMeatNews that the US cattle industry was continuing to respond and remain proactive when using antibiotics in domestic herds. “Through strict guidelines, US beef remains the safest in the world,” she said.
The first study assessed antimicrobial use at 378 cattle feedlots with a capacity of 50-99 head.
At that time, 87.5% of feedlots gave antimicrobials in feed, water or by injection (the latter mainly for cattle at high risk of disease).
Furthermore, antimicrobials were given in feed at about 70% of feedlots to prevent, control or treat respiratory disease, to prevent or treat coccidiosis and to promote growth. Meanwhile, a majority of feedlots (80%) routinely called on the services of a veterinarian and most of them (about 85%) had a veterinarian-client-patient relationship (VCPR).
Meanwhile, the study evaluating antimicrobial use in 199 swine operations with at least 1,000 market pigs showed that antimicrobials administered in water and feed were given mainly to treat respiratory illness and diarrhoea.
More than 75% of these sites gave market pigs antimicrobials in water and 90% of sites gave market pigs antimicrobials in feed. About 90% of sites that had nursery-age pigs and about 83% of sites with grower/finisher-age pigs gave antimicrobials in feed.
A veterinarian was involved in decision-making at most pig sites, deciding when and which antimicrobials to use in feed and water. Over 98% of swine sites had a VCPR.
APHIS said it would conduct periodic studies in future to monitor changes in antimicrobial use practices in these food animals – to ensure usage was not abused.
Fogarty, however, called for broader surveys in future, noting the sample size was less than 1% of the nearly 26,000 cattle feeding lots across the country. A larger sample size was needed in future studies, she said, to have “a better understanding of antimicrobial use in the livestock industry”.