Health outcomes following antimicrobial treatment of septic arthritis in Canadian feedlot calves.

Objective: To assess the clinical efficacy of treating septic arthritis (SA) with 3 different antimicrobials: oxytetracycline, florfenicol, and tulathromycin.

Animal: The study population comprised fall-placed steer and heifer calves at 4 commercial western Canadian feedlots. All calves received tulathromycin at induction for bovine respiratory disease (BRD).

The prevalence and antimicrobial resistance of respiratory pathogens isolated from feedlot cattle in Canada.

Objectives: The purpose of this study was to characterize the prevalence of antimicrobial resistance in , , and isolated from healthy feedlot cattle over 2 years, and investigate factors potentially associated with recovery of resistant isolates.

Methods: Deep-guarded nasopharyngeal (NP) swabs were used to sample feedlot cattle in multiple randomly selected feedlots (2019  = 21, 2020  = 26) at 2 timepoints. NP swabs were collected from 16 animals in each enrolled group upon entry processing and later in the feeding period.

Antimicrobial Use on 36 Beef Feedlots in Western Canada: 2008-2012.

The accurate quantification of antimicrobial use (AMU) in production animals is critical for monitoring trends in exposure to antimicrobial drugs (AMD) over time and examining potential associations with antimicrobial resistance in bacteria. In this study, a census sample of cattle was used to quantify individually-dosed and in-feed AMU as both numbers of animal daily doses (nADD) and total grams of AMD (gAMD) used in cattle placed in 36 western Canadian feedlots between 1-November, 2008 and 31-October, 2012; representing about 21.5% of fed cattle in Canada during that time period.

Management of Pregnant Heifers in the Feedlot.

Pregnant heifers in the feedlot pose many economic and management issues to the producer. Heifers that enter the feedlot pregnant will have increased costs associated with them regardless of the management strategy implemented. It is imperative that practitioners be aware of management concerns associated with pregnant heifers in order to provide sound recommendations for their clients.