Confronting dairy beef residue issue

 

By Joseph Dalton, Extension Dairy Specialist, University of Idaho

 

Over the last five years, only 8% of cattle slaughtered in the US have been market dairy cows. Nevertheless, over the same time frame, market dairy cows represented 67% of the beef residue violations. 

This statistic is disturbing as antibiotic residues may cause severe allergic reactions in some people. Consequently, dairy owners, veterinarians, herd managers, and dairy employees play a significant day-to-day role in safeguarding the food supply. 

In recent years, meat packers have sharpened their focus on the quality of cattle coming into the packing plant. Inspectors from the USDA Food Safety and Inspection Service (FSIS) use both ante-mortem (before death) and post-mortem (after death) findings as bases for selecting cattle for residue testing.

Common ante-mortem conditions that are associated with a high violation risk include evidence of recent surgery, and slow, weak or dehydrated animals. Post-mortem conditions associated with increased violation risk include mastitis, metritis, injection site lesions, and abomasal disease. Only 15% of violations result from ante-mortem findings, providing evidence that comprehensive post-mortem inspections are successful in the identification of violative residues.

Carcasses found to be positive on the initial test for drug residues are retained pending further laboratory tests on kidney, liver and muscle tissues. When a residue is confirmed by further laboratory tests, the carcass is condemned, and violators are notified. The FDA conducts an on-site inspection and then sends a warning letter to the dairy owner. The warning letter clearly describes the violation and the result of the subsequent on-site facility inspection. Violators are required to respond to the warning letter within 15 days describing “the steps you have taken to bring your firm into compliance with the law.”

Warning letters are readily available on the internet and repeat violators are placed on the USDA FSIS Repeat Violators list, which is also available on the internet. Repeat violators may be subject to civil litigation, penalties, and loss of marketing privileges.  

A quick review of warning letters shows that many have the following statement included: “Our investigation also found that you hold animals under conditions that are so inadequate that medicated animals bearing potentially harmful drug residues are likely to enter the food supply.” Consequently, the FDA is also concerned about a potential link between dairy beef residues and milk residues.

Specifically, “the FDA is concerned that the same poor practices that lead to drug residues in tissues might also be leading to drug residues in milk, especially of non-beta lactam drugs,” according to Deborah Cera, Division of Compliance, Center for Veterinary Medicine, FDA. As outlined by the Pasteurized Milk Ordinance, all farm bulk tank milk and tanker truck milk must be tested for evidence of beta-lactam residue prior to processing. The system in place is effective as very few samples (.021% of 3,182,972) were found to be positive for beta-lactam residues in 2011(National Milk Drug Residue Database). Unfortunately, USDA FSIS data indicates that greater than 50% of the violative drug residues in dairy beef are from drugs other than beta-lactams.

Therefore, in 2012, FDA investigators will collect 900 milk samples from dairies with previous dairy beef antibiotic residue violations.  The same number of cohort samples from dairies not known to have had violative dairy beef antibiotic residues will also be collected. The sampling program is expected to take one year to complete.

How will milk samples be collected? FDA investigators will provide milk processor laboratory staff with a list of producers with a previous antibiotic residue violation in dairy beef and ask laboratory personnel to provide a sample from those dairies. Coded vials will be provided to the laboratory staff and samples already collected by certified milk haulers will be used. All 900 samples from dairies with previous dairy beef antibiotic residue violations will have the same code. A second vial, for the 900 cohort samples, will be provided and will be labeled with a different code. Consequently, the vials will not be traceable to individual farms. 

All samples will then be shipped frozen to an independent third-party laboratory. This laboratory will hold the samples for one month to eliminate the possibility of tracing a sample to a particular processor, state, or producer. After one month, the samples will be sent to an FDA laboratory for testing.

Milk samples will be tested for 29 antibiotics and flunixin (a non-steroidal anti-inflammatory drug). The FDA plans to use data from this program for the Milk Drug Residue Risk Assessment. The stated purpose of the program is to determine if a problem exists; consequently, no enforcement action will occur as a result of violative levels of residues in these samples.

 

Tools available

Food safety remains an important issue for producers and consumers. Many tools are available to help avoid antibiotic residues in milk and dairy beef: 

• “Milk and Dairy Beef Drug Residue Prevention Manual,” available free from the National Milk Producers Federation at www.nationaldairyfarm.com/

• “Dairybeef: Maximizing quality and profits” website: This website (http://dairybeef.ucdavis.edu) contains videos, narrated slide sets, and on-farm tools regarding meat safety and quality. In addition, key segments have been translated and are available for Spanish speaking farm employees.

• “Avoid Residues” website: Sponsored by Pfizer Animal Health, this website (www.avoidresidues.com) contains videos and risk assessment tools for use by producers and veterinarians. 

• “Banamine” website: Sponsored by Merck Animal Health, this website (www.banamine.com) contains a residue avoidance training module in English and Spanish. 

• “Idaho Dairy Beef Quality Assurance” book: Developed by a University of Idaho Extension Team to help dairy producers educate their employees about the importance of beef from market dairy cows. To request a copy of the English or Spanish version, send an e-mail to: idahobqa@uidaho.edu.

For more information regarding residue avoidance in milk and dairy beef, contact your veterinarian, pharmaceutical representative, or local Cooperative Extension to help implement a strategy to avoid violative residues in milk and dairy beef.  

 

FYI

■  To contact Dr. Joe Dalton, Extension dairy specialist, University of Idaho, e-mail him at jdalton@uidaho.edu.