A Dairy Farm Survey of Antibiotic Treatment Practices, Residue Control Methods and Associations With Inhibitors in Milk.

A mail survey was conducted of dairy producers who had received a positive bulk milk antibiotic residue test result in a two-year period (1987-88) of government monitoring (case farms) and farms that were negative for all tests conducted in the same period (control farms). Farmers were asked to complete questionnaires designed to determine dairy management practices, as well as, antibiotic handling and residue prevention methods. Using multiple logistic regression analysis, and adjusting for the size of the milking herd, the following factors were associated with increased risk of antibiotic residues in milk: the use of part-time assistance in milking, use of a milking parlor and increased estimated frequency of intramammary antibiotic treatments.