Antimicrobial use in 22 U.S. beef feedyards: 2016–2017

Abstract

This study describes antimicrobial use in 22 U.S. beef feedyards by use of two metrics: milligrams of antimicrobial per kilogram of liveweight sold (mg/kg‐LW) and antimicrobial regimens per animal year (Reg/AY). The primary objectives were to determine the feasibility of collecting antimicrobial use data at the level of the production system and to identify factors unique to feedyard systems which may confound interpretation of summarized antimicrobial use measures. Records were accessed directly from feedyards or through a data intermediary and then subjected to a process of standardization and quality assurance. Use is reported at the study level with all individual cattle lots from all feedyards combined, as well as at the feedyard level where values were first calculated for each feedyard and then expressed as means, standard deviations and median values. Use at the study level is first reported by antimicrobial class and then by antimicrobial class within the use categories of in‐feed, control of bovine respiratory disease (BRD) and individual animal treatment. Due to wide variations of antimicrobial class within use category, feedyard level antimicrobial use is reported only by antimicrobial class. Use values for medically important and not medically important antimicrobial classes are reported separately. Regimens are described for each antimicrobial class within use category by milligrams per regimen and by timeframe from first to last administration. The authors’ selection of measures reported here was driven by a desire to minimize necessary assumptions, resulting in transparent reporting of values which can be directly related back to the factors within feedyard systems which may have influenced calculations. Reporting the number of regimens stratified by antimicrobial class within use category and then describing the characteristics of the reported regimens (milligrams per regimen and timeframe) optimize these objectives for reporting.

Antimicrobial use in wean to market pigs in the United States assessed via voluntary sharing of proprietary data

“…Another distinction of the study was that it focused solely on growing pig production, rather than the entire industry. This parallels the approaches adopted in the corresponding projects on beef cattle, broilers and turkeys (Hope et al, 2020; Singer et al, 2020a, 2020b). Variability in age susceptibility is a recognized characteristic of the epidemiology of most swine diseases, and infectious diseases are generally more problematic in younger animals than in adult breeding stock (Lekagul et al., 2019).…”

Comparison of surveys and use records for quantifying medically important antimicrobial use in 18 U.S. beef feedyards

“…All materials and methods refer to data gathering and management procedures specific to the surveys. Procedures for the collection of antimicrobial use data from feedyard records, which are used for comparison in this report, have been previously described in a companion article (Hope et al., 2020). Briefly, antimicrobial use data were collected across a wide range of feedyard sizes and record types.…”

“…The multiple parameters of a regimen include the drug product, route, milligrams per regimen, milligrams per administration, number of administrations and the time frame of the period of administration. The characteristics of regimens as described from antimicrobial use data in the companion paper are described there (Hope et al., 2020). For the data reported here, a regimen is a reported administration(s) of a medically important antimicrobial in the stated manner.…”

“…National sales data can be used to monitor changes that occur on a macro level; however, their primary disadvantage is that they lack the granularity to develop and evaluate stewardship initiatives at the farm level where treatment administration occurs. An example of differing granularity as to use practices is the comparison between the Food and Drug Administration Center for Veterinary Medicine (FDA CVM) yearly reports and recently published reports of data generated at the individual production unit level (Brault, et al., 2019; Food & Drug Administration Center for Veterinary Medicine, 2019; Hope et al., 2020). The FDA CVM report contains sales data by antimicrobial class whereas the cited beef feedyard antimicrobial use reports also separate the data by categories such as indication for use and means of administration.…”

“…Therefore, the objective of this study was to evaluate agreement between medically important antimicrobial use metrics derived from in‐person surveys of feedyard management as opposed to metrics derived from production unit‐level antimicrobial use records. Specific details regarding the methods for antimicrobial use data collection and management for 22 U.S. beef feedyards, descriptions and calculations for the reporting metrics, and a glossary of terms have been previously reported (Hope et al., 2020). Due to limitations in record types and survey administration, 18 of these feedyards provided both survey and record data as the basis for this report.…”