Reference | Ray2006 (10092)

One hundred and thirty one dairy farms from New York, Michigan, Mnnesota, and Wisconsin were enrolled in this study. Herds were selected based on herd size and management type (organic or conventional). Conventional herds enrolled were obtained by ranomly selecting 97 farms from a list of 295 conventional farms that responded with an interest in participation in the study and met eligibility criteria. All organic farms enrolled in the study were under organic management for at least 3 years prior to enrollment in the study. Environmental and fecal samples were collected at approximately 2 month intervals from August 2000 to October 2001 at 32 organic farms and 97 conventional farms. Fecal samples were taken from healthy cows and target cattle groups consisting of prewaned calves receiving milk or milk replacer, cows to be culled within 14d, cows within 14d of calving and sick cows. Sick cows were defined as cows designated as sick by farm workers or a veterinarian within the previous week or cows having clinical signs of illness evident to farm or project workers on the day of visit (except for localized reproductive tract or mammary infections).

A new glove was used to collect approximately 10g of fecal material from the rectum of each animal. At each visit one sample was taken from the calving pen floor, sick pen floor, calf pen/hutch floor, feed bunk of lactating cows, maure storage area, and bird droppings from cattle housing/feed storage areas. These samples were collected by wiping areas with sterile gauze soaked with double strength sterile skim milk.

AST Method: Broth Microdilution

Reference explicitly reports AST breakpoints: False

Reference reports using a MIC table: False