Mueller, Hans Christian and Van Bibber-Krueger, Cadra L. and Ogunrinu, Olanrewaju J. and Amachawadi, Raghavendra G. and Scott, H. Morgan and Drouillard, James S. (United States of America)
None (2018)
312 crossbred steers (411.4 ± 6.71 kg) were blocked by initial BW and randomly assigned to a treatment group. Treatments included a negative control group (no tylosin phosphate throughout the finishing period), a positive control group (tylosin phosphate fed continuously throughout the finishing period), and a group that received tylosin phosphate off-label by feeding the drug on a repeated intermittent basis (1 wk on, 2 wk off). Tylosin phosphate was fed at a rate of 9.9 mg/kg DM. The study was a randomized block design.
Fecal samples were collected from 8 randomly selected animals per pen, per sampling day (0, 20, and 118). Enterococcus-presumptive isolates from 2 animals per pen/day were randomly selected from each treatment group for MALDI-TOF (Matrix-Assisted Laser Desorption Ionization-Time of Flight) analysis. Samples were cultured on non-selective, erythromycin-selective (8ug/ml) and tetracycline-selective (16ug/ml) media.
AST Method: None
Reference explicitly reports AST breakpoints: False
Reference reports using a MIC table: False
Is Excluded: False
| Country | Sub-Region | Sub-Region Detail |
|---|---|---|
| United States of America | Kansas (State) | Kansas State University Beef Cattle Research Centre (Manhattan, KS). |
| ID | Note | Resolution |
|---|
| Title | Host | Host | Production Stage | Description | ROs |
|---|---|---|---|---|---|
| In-feed Tylosin | Cattle | Beef Steers | Feedlot | Received continuous (118 day) in-feed tylosin phosphate. Tetracycline-selective media was used. | 1 |
| In-feed Tylosin | Cattle | Beef Steers | Feedlot | Received continuous in-feed tylosin phosphate, 118 days. Erythromycin-selective media was used. | 1 |
| In-feed Tylosin | Cattle | Beef Steers | Feedlot | Received intermittent in-feed tylosin phosphate in a 1 week on, 2 week off pattern (118 days). Tetracycline-selective media was used. | 1 |
| In-feed Tylosin | Cattle | Beef Steers | Feedlot | Received intermittent in-feed tylosin phosphate in a 1 week on, 2 week off pattern, throughout the feeding period, 118 days. Erythromycin-selective media was used. | 1 |