Reference | Moro2000 (10069)

Finisher pigs (85 k) from a farm where feed had not beensupplemented with antibiotics for over 10 years were usedin this study. Randomly selected animals from a single pen. Study 1: Ten finisher hogs were randomly allocated to three groups. All groups were exposed to controlled temperatures of 34 C (heat stress) and 65% relative humidity for 24 h. Study 2: Four groups (A, B, C and D) of three randomly selectedanimals each were formed. Groups B, C and D wereexposed to controlled temperatures of 34C (heat stress)and 65% relative humidity in the following way. Group B was exposed to heat stress for 8 h and the animals were immediately slaughtered afterwards; group C was exposed for 24 h and slaughtered immediately afterwards, andgroup D was also exposed for 24 h but was slaughteredafter 1 week. Group A was an unexposed control. Study 3: Six pigs were randomly allocated in two groups (three ani-mals per group). Intestinal hypermotility wasinduced by the use of neostigmine methylsulphate 0.03 mg/kg).Two intramuscular injections were administered 17 and 9h prior to slaughter of the experimental group. Control ani-mals were injected with distilled water at the same timeintervals.

Study 1: Faecal samples were collected on a weekly basis prior to the initiation of treatment as well as every day during, and for 10days after terminating stress. Rectal temperatures were measured before and at the end of stress. Study 2: Rectal temperatures measured before treatment and again at the termination of stress. Weekly faecal samples were collected prior to the initiation of the study. All groups wereslaughtered at the meat laboratory. Both ends of a 20 - 30 cm segment of ileum, ileocaecal valve-caecum, ascending colon, transverse colon, descend-ing colon and rectum were ligated and the segments removed. Culturing of samples was performed within 2 h of obtaining the intestinal segments. Carcass surfaces were cultured at the meat laboratory so that any E. coli represented bacteria of faecal origin. The ham, back, shoulder and peritoneal cavity were sampled by swabbing 250 cm2with absorbent cotton swabs and placedin 10 ml Phosphate Buffer Solution (PBS). Study 3: Faecal samples were collected on a weekly basis prior to the initiation of the study for determination of baseline prevalence of ampicillin and tetracycline resis-tance of intestinal E. coli. Animals were slaughtered at the Iowa StateUniversity Meats Laboratory. Samples of 20 - 30 cm seg-ments of ileum, caecum, colon and rectum were ligated atboth ends and removed. Culturing of samples was per-formed as described in study 2.

AST Method: Multiple Methods

Reference explicitly reports AST breakpoints: True

Reference reports using a MIC table: False