For Veterinarians: Antimicrobial Residues and Molecular Testing

Drug Residue Déjà Vu: Avoiding Residues in Milk and Cull Dairy Cows

Dr. Pamela Ruegg, Dairy Science Department, University of Wisconsin-Madison
While mastitis is the most common disease of adult dairy cows and accounts for most usage of antibiotics cows are also treated for other infectious diseases, including respiratory and uterine infections and infectious foot disease. The risk of antimicrobial residues in meat and milk is well known and if the focus of intensive regulatory processes. The purpose of this paper is to review important data about how antimicrobials can be safely and judiciously used on dairy farms.

PCR, PFGE, ABCD…Understanding and Using Molecular Tests to Diagnose and Control Mastitis

Dr. Pamela Ruegg, Dairy Science Department, University of Wisconsin-Madison
The technical definition of mastitis is “inflammation of the mammary gland” but on a practical basis, almost all bovine mastitis is caused by bacteria. Appropriate mastitis control is based on knowledge of the etiology, thus identification of pathogens is a fundamental aspect of mastitis control programs. The use of molecular techniques to identify bacterial DNA from milk samples is increasingly used in an attempt to improve diagnosis. The purpose of this paper is to discuss practical aspects of using these tests in mastitis control programs.