Effects of in-feed Chlorotetracycline (CTC) use in feedlots, on both animal health and antimicrobial-resistant E.coli
This study investigates whether in feed CTC increases antimicrobial resistance in the early stages of a respiratory disease outbreak. Each of the feedlots received CTC treatment in-feed for 5 days, in calves less than 6 months old (150 treated and 150 untreated controls). The results showed that the CTC treated group had reduced morbidity, reduced use of antimicrobials considered critical to human health and no long-term impact on the occurrence of antimicrobial-resistant E.coli. Control cattle (untreated with CTC) were also recorded as being unhealthy on the 8th day after arrival at the feedlot. Of the untreated cattle, over 25% (38/150) developed illness requiring treatment with antibiotics critical to human health, compared to only 1.3% (2/150) in the group receiving in-feed CTC.
To see the detailed discussion of the study please read the full research article called: Chlortetracycline and Respiratory Disease in young cattle.