Reference | Piddock_2008_JoofAnCh (10321) (Excluded)

All three flocks, A, B and C, were broiler birds removed from commercial poultry flocks reared for human consumption. The treatment histories of the birds were obtained and none had previous exposure to tetracycline or other antimicrobials. These birds were housed at a stocking density of 12.6 kg/m^2 and experimentally treated with chlortetracycline. Each group of birds was housed independently in separate rooms. Flock A consisted of 20 birds brought on-site at 21 days of age from a commercial free-range organic broiler flock consisting of 7500 birds in September 2004. All birds were treated with a therapeutic dose of chlortetracycline at 40 mg/kg/day for 6 days administered in the feed as recommended by the manufacturer. All birds were weighed before therapy commenced. Food consumption was not measured; however, animal care staff confirmed that the animals fed normally. Flock B consisted of 28 birds brought on-site in October 2005, purchased from a commercial free-range broiler flock of 6300 birds at 22 days old. Fourteen of these birds were treated with a therapeutic dose of chlortetracycline and 14 birds, housed independently, remained untreated. Flock C consisted of 30 birds brought on-site at 49 days old in May 2006, purchased from a commercial housed corn-fed ‘freedom foods’ flock consisting of 31 000 birds. Fifteen of these birds were treated with a therapeutic dose of chlortetracycline and 15 birds, housed independently, remained untreated.

At least 14 freshly voided faecal samples were collected before, during (2 days after treatment started) and every 7 days thereafter up to 4 weeks post-treatment. At 4 weeks post-treatment sampling, the caeca from flock B were removed post mortem to enable analysis of each chicken’s flora for Campylobacter spp.

AST Method: Unclear

Reference explicitly reports AST breakpoints: Uncertain

Reference reports using a MIC table: Uncertain