Although bucking stock are not raised primarily as meat for human consumption, there are certainly bulls and older cows that end up in the human food chain at the end of their career. In this issue of Bull Pen we will shift from our usual perspective of bucking stock as performance animal and shift to bucking stock as a member of a food animal species.

Elite PBR bulls have personality, talent, and devoted owners that do not see their investment as a food animal species. However, in the eyes of the Food and Drug Administration (FDA) these bulls are just that, food animals. As such these animals, as with all bucking stock, are subject to the rules of proper medication use and withdrawal times as set forth by the FDA in order to protect potential human consumers. All veterinarians that work on bucking stock should be aware of the regulations concerning appropriate drug use and be able to educate the bull owner on proper route of administration, withdrawal time, and caution against the use of illegal drugs in these animals. In addition many drugs that work well on species such as horses or dogs are either illegal or have no therapeutic effect in bovines. Your veterinarian has a responsibility to educate you, as bull owner, on these issues. Should an animal end up at a federal slaughter facility and test positive for a drug residue both the owner and the veterinarian are subject to disciplinary action. Furthermore, governmental organizations are always threatening to take away or further restrict the use of drugs in food animal species due to ongoing misuse of important categories of drugs such as antibiotics. ABBI members should take time to educate themselves on these very important issues in order to keep the bucking bull industry moving forward in an ethical manner. Bull breeders and owners should think of themselves as cattlemen first and performance animal caretakers second.

The FDA has published a list of prohibited and restricted drugs for use in food animal species. The list grows slowly over time and is updated as data showing a perceived threat to human health from drug exposure is generated. The list is available online at www.farad.org. FARAD is a government subsidized organization staffed by scientists and veterinarians that are dedicated to food safety. If a food animal has been exposed to a drug, either intentionally or by accident, FARAD will give any veterinarian confidential information regarding appropriate withholding times for that animal. This organization occasionally loses its governmental funding and is shutdown. As the ABBI continues to grow in membership and revenue, lobbying for such an organization as FARAD should become a topic for ABBI directors to discuss. As to the list there are two drugs, clenbuterol and Baytril® or enrofloxacin, that are 100% illegal to use in mature bucking bulls (or cows). Baytril® has a labeled use for pneumonia in beef and dairy calves. Clenbuterol is prohibited from use in ANY bovine regardless of age or sex. Other drugs on the FDA list are prohibited in subsets of the bovine world. For example most sulfa drugs and phenylbutazone are prohibited in lactating dairy cows. Chloramphenicol is also 100% illegal to use in any food animal species.

Aside from the prohibited list, certain drugs are labeled for specific administration in cattle. The popular antibiotic Excede® is labeled for injection at the base of the ear. This is due to the long half life of the drug and long residue time at the injection site. The proper site of administration is trimmed at slaughter and poses no risk for the consumer. Should Excede^® be given at any other site in a bull or cow, for example the neck, then the drug will persist at that site for weeks. The outcome of this error, should the animal go to slaughter, is a trim lesion generating suspicion for drug residue in the animal and subsequent carcass holding, testing, possible condemnation, and potential fines and disciplinary action.

A further cause for concern is the use of drugs that are not illegal to use in cattle but carry a prolonged withdrawal time. Gentamicin sulphate or Gentocin® is perhaps the best example of this category of drug. Although not labeled for use in cattle there is an accepted meat withdrawal time of 18 months. The difficulty comes in tracking an animal for 18 months. Perhaps the initial illness responded to gentamicin but 7 months later the cow or bull suffers a career ending injury. If the animal is still ambulatory and in good flesh then slaughter becomes an economic means of disposal and potential recap of lost income. However, that animal is STILL INELIGIBLE for slaughter due to the prolonged meat withdrawal time from an antibiotic given months earlier. Drugs such as gentamicin must not be used without careful veterinary client communication as set forth by a document known as AMDUCA. Included in this discussion is the establishment of the need for this unlabeled drug to save the animal’s life as well as the agreement by the owner to abide by the prolonged withdrawal time.

Finally some drugs are not only illegal to use in bovines but ineffective as well. Tucoprim, trimethoprim sulfa, TMS, or SMZ pills and powder are commonly used, effective, antibiotics for horses. Unfortunately once the rumen gets a hold of the trimethoprim component of these preparations it is chemically destroyed and therefore unavailable for absorption in the small intestine and distribution to the problem site of infection, such as the horn.

Finally, be careful when medicating bovines. Enough drug residues can be licked from an empty food bucket by a pen mate to result in positive drug testing for that animal. Clean syringe guns thoroughly between use or use new syringes for each animal. And remember that drugs such as Micotil are usually lethal for human beings, should accidental injection occur.