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Practical ways to reduce our use of antibiotics

Practical ways to reduce our use of antibiotics

The livestock industry has made great strides in addressing the topic of antimicrobial usage and indirectly lessening the opportunity for the formation of antibiotic-resistant bacteria. From veterinarians setting treatment protocols to cow-calf and feedlot producers implementing effective coping strategies, progress is being made in minimizing the incidence of disease and thus reducing the need for antibiotics.

This article will address some of the changes you can make to hopefully decrease the incidence of disease in your operation and therefore reduce the need to use more antimicrobials in our calves.

The first step is to develop herd health measures with your veterinarians and nutritionist to maximize disease resistance in your calves. This involves proper and complete vaccination protocols (including all the respiratory and clostridial pathogens), boostering vaccines at the appropriate time coupled with good nutrition and maximum parasite protection. Knowledge of the diseases prevalent in your area and using these vaccines at the recommended age on non-stressed cattle should maximize protection.

True preconditioning programs where calves are immunized prior to weaning and then weaned either using fenceline weaning or two-stage weaning (with nose flaps) have shown the best results at reducing respiratory morbidity and mortality. This, of course, takes extra effort and cost but is the right thing to do. Preconditioning programs took off in the 1980s but soon fizzled when producers did not realize financial benefits from doing it. When done properly, however, it can substantially reduce the need to treat with antibiotics.

Under certain conditions the use of mass medication at entry to the feedlot (metaphylaxis) may be avoided with these preconditioned calves. This only works well if cattle are directly shipped from farm to feedlot and not commingled with calves from other herds. Remember, vaccination is not a 100 per cent guarantee that calves won’t get sick. When a well-vaccinated herd is boostered it provides good protection to 90 per cent or so of the calves. Inside the feedlot the exposure level, the stress the calves are under, transportation distance, feed changes, handling stress and ability to find feed and water in a new pen all contribute to the morbidity level from respiratory disease. Morbidity level coupled with the identification and early detection of disease determine how many antimicrobials are needed.

Vaccines are improving all the time in terms of the spectrum of protection, length of protection and quickness of protection. Much of the current research is focused on protection against BVD, bovine respiratory disease. This is where most of the antimicrobials are used in the beef production chain, primarily in the first one to two months after arrival at the feedlot.

There are now more intranasal vaccines, which provide local immunity in the windpipe and nasopharnyx. This immunity occurs quite rapidly. Some intranasal vaccines are developed for respiratory viruses and another for respiratory bacteria. This quicker protection might also cut down on the incidence of respiratory disease.

Whenever you are vaccinating, remember to store (keep refrigerated until use), rehydrate and use modified vaccines within one hour, inject them in the proper locations and have ephinephrine on hand in case of a rare allergic reaction. The proper application of vaccines means your herd will be better immunized and require less antibiotic treatment. You pay good money for vaccines, so use them properly.

There are many alternative products to antibiotics — NSAIDs (non-steroidal anti-inflammatory drugs), probiotics, electrolyte solutions such as Destress, essential oils or gases such as nitric oxide — to treat respiratory disease. Each one needs to be considered by your veterinarian on its own merits. There is no doubt that NSAIDs are prescribed by most veterinarians these days as an adjunct therapy for most infections and inflammatory conditions such as respiratory disease.

Early detection methods such as thermography to monitor movement or activity, as well as a stethoscope coupled to a computer program (whisper technology) may go a long ways towards detecting clinical cases of respiratory disease earlier. This may change the type and duration of antibiotics necessary to control the disease.

Immune stimulants also show promise and some have already hit the market so time will tell how effective they are in a feedlot or cow-calf setting. If they prove effective they may become an adjunct to vaccination to further reduce the need to treat or prevent respiratory disease. It will probably take a couple of years to prove them out.

In the meantime proper and timely diagnosis is essential to the effective use of antimicrobials. Infections acted on too slowly require more antibiotics and if used to treat the wrong condition produce poor results. Lameness, which has become the second-most treated condition in many feedlots, is a prime example. True footrot responds very favourably to many antibiotics whereas a sole abscess may need to be pared out while a sprain may simply need time to heal rather than antibiotics.

You must assess each medical case with the question: Do I really need antibiotics? If in doubt your veterinarian can provide guidance and protocols for specific disease conditions. Localized abscesses, for instance, if lanced and flushed and drained may or may not need followup treatment with an antibiotic.

Contact your veterinarian in instances where there is a lack of response to antibiotics or recurrent cases, as a culture of the organism may reveal a resistance pattern. We often see resistance to families of antibiotics so defaulting to a secondary treatment with a very similar antibiotic may not be the right answer. This illustrates the need for more individual attention.

In the future, more direct shipping of load lots of cattle from the ranch to the feedlot should minimize our treatment levels. Satellite and video auctions offer ways to get this done and subsequently cut overhead costs while minimizing the stress of transportation and commingling to deliver a healthier calf to the feedlot.

Healthy calves, particularly ones that arrive with an exact description of their vaccination and treatment history, get on feed quicker.

All sectors of the cattle industry need to work together to reduce antibiotic use. They will always be needed to treat sick animals, but some changes in management along the beef chain can really minimize their use and perhaps ensure that they will always be available to deal with life-threatening disease.

About the author


Roy Lewis is an Alberta-based veterinarian specializing in large-animal practice. He is also a part-time technical services vet for Merck Animal Health.



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