In 2008 dairy cull cows accounted for 8% of all cattle harvested (excluding veal) at federally inspected plants. While dairy cull cows are a small part of total beef production, they carry a heavy burden — accounting for 90% of cattle residue violations (excluding veal) from inspector generated samples.

National Agriculture Statistics Service data indicates that in 2008 33,805,100 cattle (excluding veal) were slaughtered in federally inspected plants. Of those, 879 suspect cattle tested positive for a violative chemical residue (0.003% of cattle slaughtered). The distressing part of this data is that 791 of the positive cattle were dairy cull cows (90% of suspect cattle that tested positive for a chemical residue violation at slaughter).

Violative residues were detected in 0.03% of all dairy cows slaughtered. In comparison, violative residues were detected in 0.001% of all beef cows slaughtered. So, while the percentage of violative residues detected in harvested dairy cows appears to be small, it is 30 times greater than the percentage of violative residues detected in harvested beef cows (numbers adapted from USDA 2008 National Residue Program data).

Legislators are taking notice

Issues that affect the quality and safety of beef that originates from cull dairy cattle are an on-going concern for the beef industry. Any level of violative residue is unacceptable in the food industry. 

Legislation is being considered in Washington, D.C. that would withdraw the routine use of seven classes of antibiotics from food animal production unless animals or herds are sick or unless drug companies can prove that their use does not harm human health. The Preservation of Antibiotics for Medical Treatment Act of 2009 has support of the American Medical Association, the American Public Health Association, the Infectious Diseases Society of America, the American Academy of Pediatrics and some 350 other organizations. The American Veterinary Medical Association, the American Association of Bovine Practitioners, the Academy of Veterinary Consultants and the American Association of Swine Veterinarians oppose the proposed legislation.

Legislative attempts to severely restrict or eliminate the use of antimicrobials in livestock are not the answer to these issues. Antimicrobials and other pharmaceuticals are an important tool in the production of safe and wholesome food such as beef. Restricting the use of these important tools has the potential for negative effects on animal health and welfare as well as human health. 

Mastitis, followed by reproductive disease and lameness are the three most common diseases for which antibiotic treatments are used on dairy operations, according to the National Animal Health Monitoring System Dairy 2007 study. The report indicates that cephalosporin was the most common type of antibiotic used by operations to treat all diseases, while B-lactam antibiotics, such as penicillin, were the second most common type of antibiotic used to treat mastitis and reproductive diseases, and the third most common type of antibiotic used to treat lameness. This usage mirrors antibiotic residue data reported by federal inspectors using on-site antibiotic residue testing, in which penicillin was identified as the most common violative residue detected in dairy cull cows according to the USDA.

Causes of antibiotic residues

Common situations leading to unintentional misuse of antibiotics may include insufficient knowledge about drug withdrawal periods, employee error, insufficient treatment records, poor identification of treated animals, and inadequate communication between veterinarian and producer.

A recent survey of antibiotic use and biosecurity practices among Washington state dairy producers and published in a 2006 Journal of Dairy Science highlights many of these underlying gaps. Out of 381 respondents, less than one-third had written protocols for diagnosing or treating common medical conditions. Most agreed that such protocols could reduce errors and production losses.

In a University of Minnesota survey, more than 18% of bovine practitioners surveyed cited poor communication between veterinarian and producer as a major reason of dairy producers’ lack of compliance with drug use instructions that could potentially cause a violative residue. Lack of understanding of residue avoidance practices was cited as the second most common reason for non-compliance by producers in the study published in a 2008 Bovine Practitioner.

How is it being addressed?

The American Veterinary Medical Association has developed multi-species guidelines for judicious therapeutic use of antibiotics in multiple species. .

The Minnesota Veterinary Medical Association — Farm Animal Pharmaceutical Committee (MVMA-FAPC) works to keep veterinarian members up to date on issues related to pharmaceutical use in food producing animals. The FAPC monitors current federal and Minnesota drug regulations for food animal practitioners, communicates new information to members, and works to assist members with their efforts to be compliant with the current legal standards and guidelines surrounding the use and distribution of drugs for use in food animal species.

The University of Minnesota’s College of Veterinary Medicine has developed and piloted a new software package to aid in writing protocols and producing veterinary prescriptions under a valid VCPR. Version 1.0 of the new Veterinary Protocol Manager software is expected to be available in 2010 through the Veterinary Population Medicine Department at the College of Veterinary Medicine. 

The Center for Animal Health and Food Safety (CAHFS) at the University of Minnesota College of Veterinary Medicine and Minnesota Beef Council (MBC) work in partnership to assist dairy producers and veterinarians in ensuring that dairy beef meet beef quality assurance (BQA) standards. Recently the CAHFS and MBC have developed brochures and posters on responsible antibiotic use, available in both Spanish and English. Visit the Minnesota Beef Council for these and other BQA materials at www.mnbeef.org or the national Beef Check off-funded site at www.bqa.org.


VCPR is key to preventing residues    

Responsible use of antimicrobials and pharmaceuticals is the answer to preventing and reducing antimicrobial residues in dairy cattle. A veterinary-client-patient relationship (VCPR) is paramount to ensuring that antimicrobials and pharmaceuticals are used according to best management practices. A VCPR is not only required by law for the use of prescription veterinary drugs, but is also a valuable resource for developing protocols for routine herd management and for clinical therapy and discussion about proper drug use, withdrawal time, antibiotic resistance and disease prevention practices.

A VCPR is the heart of the practice of veterinary medicine — it is the basis for interaction among veterinarians, their clients, and their patients. As defined in the AVMA’s Principles of Veterinary Medical Ethics of the American Veterinary Medical Association, a VCPR exists when all of the following conditions have been met:

  • The veterinarian has assumed responsibility for making clinical judgments regarding the health of the animal(s) and the need for medical treatment, and the client has agreed to follow the veterinarian’s instructions.
  • The veterinarian has sufficient knowledge of the animal(s) to initiate at least a general or preliminary diagnosis of the medical condition of the animal(s). This means that the veterinarian has recently seen and is personally acquainted with the keeping and care of the animal(s) by virtue of an examination of the animal(s), or by medically appropriate and timely visits to the premises where the animal(s) are kept.
  • The veterinarian is readily available, or has arranged for emergency coverage, for follow-up evaluation in the event of adverse reactions or the failure of the treatment regimen.

Source: Jennifer Koeman, DVM, MSc, Center for Animal Health and Food Safety, University of Minnesota; Tim Goldsmith, DVM, MPH, Center for Animal Health and Food Safety, University of Minnesota; Ron Eustice, Director Minnesota Beef Council