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Antibiotics in Animal Feed

Paper Type: Free Essay Subject: Biology
Wordcount: 2990 words Published: 8th Feb 2020

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Animal products are a huge staple in the American lifestyle. Whether it be from a fast food chain or from an organic food market, lots of people spend lots of money to buy and eat animals. In order to meet the high demand for animal meat the industry has been looking for ways to increase production while making major profits. One way that they discovered was extremely effective was the use of antibiotics as an additive in animal feed. While antibiotics have brought overwhelming benefits to the animal industry, their use comes with risks that are prevalent enough that there needs to be a drive towards safe alternatives.

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Antibiotics began to be additives in animal feed in the mid-1900s. By that time, penicillin was already being used in human health, and the introduction of antibiotics into animal feed was started by the microbiologist Selman Waksman (Dibner, 634). Waksman had been working at the New Jersey Agricultural Experiment Station on drugs for livestock when he was rewarded the Nobel prize for discovering streptomycin. Streptomycin’s discovery was a very useful discovery for dairy farms, as it assisted in the curing of mastitis, which infects the udders of the cattle (534). The scientists then noticed that animals that were given antibiotics were healthier and had a faster growth rate, even on the same amount of food (635). This convinced them to start adding antibiotics into all the animals’ feed, even if they weren’t sick.

Then in 1951, the FDA approved the use of antibiotics in animal feed to increase their weight rather than to make them healthy. Putting additives into animal feed was done for purposes of compensating for the shortage of livestock crops that happened during the war (635). The use of urea, and later other compounds like proteins and vitamins in animal feed showed to improve growth rates and productivity of the livestock. This also allowed for the size of the herds to increase. Before the use of antibiotics, contagious diseases could be spread rapidly to large groups of animals and end up killing large amounts of animals. With the addition of antibiotics, larger herds could be contained without worry, increasing productivity and reducing production costs.

Since the 1900s, the industry for additives in animal feed has grown. In fact, the United States National Research Council has predicted that the industry will be worth billions by 2020. Dr. Michael J. Martin of the American Public Health Association (APH) says that “of all antibiotics sold in the United States, approximately 80% are sold for use in animal agriculture” (2409). A majority of those antibiotics are not used to treat diseases but are used as growth promoters instead. This practice is not only popular in America; worldwide the animal industry is putting additives into their animal feed in order to grow ‘better’ animals. Especially in countries that are more poverty stricken, having growth promoters allows for more food that is of a better quality.

The FDA has been implementing laws and has been keeping an eye on the drugs that are placed in the feed. The organization has made sure that the drugs can only be used under a Veterinary Feed Directive (VFD) that’s issued by a practicing veterinarian (Altekruse, 709). Since the drugs that are put in animal feed are not used as actual medication to treat a sickness the animal has, their prescription status is written under the VFD to “minimize the potential public health risk associated with the use of antibiotics in animal feed…” (709). The VFD process has a veterinarian determine if the animals’ conditions are enough to distribute a VFD drug. If yes, the veterinarian can give a prescription for either a specific kind of animal feed, or a more general one that is meant to increase growth and overall animal health. Only a licensed veterinarian can be used for this approval process, and their job isn’t done after the approval. They have several responsibilities like: making medical judgements regarding the health of the animal, make visits to where the animals are kept to medically evaluate them, and suggest alternatives if the starting treatment is unsuccessful (711).

There are clear benefits to the use of antibiotics as feed additive. In pigs, for example, it’s shown that when they’re supplemented with antibiotics in their feed, they require up to 15% less feed to reach the desired level of growth (Chattopadhyay, 334). The use of antibiotics like tetracycline and penicillin in chicken feed has shown to improve the hatchability and production of their eggs (334). All farm animals are reported to experience a marked increase in animal production and a decrease in mortality. Though there isn’t much research on the psychology of the animals that are feed antibiotics in comparison to animals that aren’t, the focus of the animal industry is to create animals that return the most profit, and antibiotics have helped the industry save millions that they wouldn’t have without the use of antibiotics.

Though the use of antibiotics has shown marked improvements in animal production, there are risks to the use (and overuse) of antibiotics. The use of antibiotics in animal feed has been a controversial topic for a long time. The concern has less to do with the effects that the antibiotics could have on the meat, but instead is focused on the chances of spreading antibiotic resistant bacteria to the general population. These pathogens result from overuse of antibiotics for benign situations; the medication is able to kill off the bacteria that are susceptible to it but leaves behind bacteria that aren’t. Those left behind are able to grow (many times as a result of the antibiotics being stopped without doctor supervision), and the same antibiotic is unable to kill the new growing strain. This means medical professionals have to search for a new antibiotic that will work, which could take time. Animals that have been feed antibiotics for long periods of time can have an increase of resistant bacteria living in their guts, which will be able to thrive even after the antibiotic is no longer supplied (Altekruse, 710). Once the animal is killed, Dr. Martin states that undercooked meat and animal manure can carry bacteria that have antibiotic resistance, and that these can be passed onto humans through contacting or ingesting them (2410). Dr. Cheng cites that there have even been strains of bacteria that have resistance to antibiotics that they weren’t directly exposed to (2014). This is very likely due to the transfer of transposons from different bacteria interacting with one another through horizontal gene transfer, or general bacterial reproduction. There’s even evidence that antibiotics could be contribution to an increase rate of mutation in bacteria, creating mutants that are resistant to multiple drugs and being stronger than their non-mutated counterparts (Chattopadhyay, 334). These strains of bacteria could be very dangerous to the public if there were able to spread and grow in people.

The spread of bacteria from animals to humans from direct contact happens more often than people realize. Most people do not eat only well-done meat their entire lives; people like their steaks and burgers medium-rare or rare. And even if a person only ate well-done meat at home, there is the risk of contamination at restaurants. Not all restaurants require their workers to wear gloves while preparing the food, and cross contamination is not only possible, but happens often. If a restaurant is given infected meat, there’s a risk that the workers and the customers end up infected with bacteria. And if the bacteria was a strain that is resistant to the antibiotics normally used to treat it, the disease could end up posing a public health risk.

Antibiotic resistance is an issue that is dangerously prevalent all around the world. If a person is infected with bacteria that is resistant to the regular treatments, there aren’t many options left for that person as far as a cure. Either they need to subject themselves to experimental medicine and hope for the best, or the person is kept in isolation from others to prevent the disease from spreading. And there is even less hope in underdeveloped countries where the medicine is not adequate for even keeping the patient comfortable. Some patients end up just waiting for death while they are kept from the general population. Until there is a solid solution for antibiotic resistant diseases that is assured to work, scientists working in the animal industry are exploring possible alternatives to using antibiotics in animal feed. Their hope is that they are able to find an alternative that has benefits similar to antibiotics but doesn’t carry the associated risks.

Alternatives to antibiotic additives in animal feed isn’t a brand-new discussion. Even in the late 1900s, when antibiotics were first being introduced into animal feed, there was questions about whether they were a stable additive to put into animals. Early papers from 1969, written by Robert C. Wornick and Gustav O. Kuhn site penicillin as an effective additive, but also talk of its instability in humidity and its tendency to break down in particular mixes of feeds. Though its stability had grown to a point where it wasn’t a concern, there was still the question of if there was a possibility of something other than antibiotics that could be effective. It’s not as simple as just removing all the antibiotics in the feed in one go though. The EU went through a period of banning the use of antibiotics in animal feed and saw an increase of animal infections and a decrease in their production (Cheng, 2014). The conditions in the farm houses are notoriously unhygienic in many places, so the use of antibiotics ends up becoming more necessary as animals are likely to catch an infection. Perhaps a way to make the demand for antibiotics less prevalent lies in improving the ways that animals are contained and treated. Whether or not the animal industry is willing to try changing that is yet to be seen; chickens, pigs and cows tend to become fatter and produce thicker meat when they’re left to sit rather than exercise, so the incentive might not be there.

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There is potential in the use of prebiotics and probiotics to replace the antibiotics. It would make sense; probiotics are added to food that people eat in order to promote the growth of healthy bacteria flora in the gut.  The general theory is that if there are benefits to people have pre- and probiotics, then the animals should be able to have benefits as well. Their use has been growing in the industry; “in 2000, the total sale of feed probiotics worldwide was $186 million” (Cheng, 2014). The research for whether the pre- and probiotics are effective can’t be determined yet, as the results that have been obtained through experiments are not conclusive (Allen 118). It seems that there are results that say the probiotics gave similar results to the antibiotics; a general increase in animal production, though not to the same degree. However, there are results saying that probiotics have caused harm in animals, including diarrhea and other adverse effects (Cheng, 2014). It seems that the results of the pre- and probiotics are very variable depending on the animal’s age, species, and its physiological state of being (2014). There’s also the issue of price; prebiotics in particular are expensive to make. In order for them to have a benefit enough to incentivize the industry to use them, the profit must be more than the loss. Because of the price and the lack of conclusive evidence of a benefit for their use, the pre- and probiotics are not replacing the antibiotics completely at the moment. But, the scientists and veterinarians are researching for more results, and are experimenting with the use of synbiotics as well. The pre- and probiotics are not under the same scrutiny of regulations the way that antibiotics are. Since there are processes and consultations with veterinarians before the use of antibiotics in animal feed can take place, if there is to be a future for the pre- and probiotics as a usable alternative.

In order for an alternative to be useful, it’ll need to pass some criteria: It needs to be non-toxic to the animals, it shouldn’t create resistant bacteria, it should have stability in the animal and not cause any adverse side effects, it should be able to prevent pathogens from growing, it can’t effect the meat itself, it can’t destroy the environment, it can’t be expensive, and it has to give benefits similar to antibiotics (i.e. growth and efficiency) (Cheng, 2014). The hypothetical alternative must be able to fill all these requirements in order to last long enough to minimize or replace the use of antibiotics, and unfortunately there aren’t any that fill all of that at the moment. Besides pre- and probiotics, there are other alternatives being looked at: vaccines, bacteriophages, plant extracts and others. But none of those match the checklist needed to replace antibiotics completely. Some of them, like bacteriophages, end up causing more harm than good. Vaccines effectiveness in terms of helping animal productivity needs to be host-specific; it’s too expensive to tailor-make vaccines in order to fit each group of animals (Chattopadhyay, 334). And plant extracts seem to have an effect on the meat quality. Until there are alternatives that can match, the chances of diminishing the use of antibiotics is undetermined. Particularly in countries where disease is more prevalent and sanitary measures aren’t as good, antibiotics allow people to eat meats with less risk of catching a disease from the meat.

The FDA has also tried to put more rules on the antibiotic-manufacturers. They’ve asked the manufacturers to put labels on their products that includes a quote that mentions the disapproval of the use of antibiotics in animal feed without a veterinarian present (Chattopadhyay, 334). These rules extend to medical antibiotics but doesn’t include the antibiotics that are animal-specific and not used on humans (334). Unfortunately, it would be difficult for the FDA to put in more regulations on the farm houses in terms of their animal feeds without likely having push back from the companies that are making money off of the use of antibiotics in animal feed. There would need to be veterinarians stationed from the FDA to check the farm houses to make sure that the animals are not being feed antibiotics that aren’t allowed.

 As the human population continues to rise, the demand for animal products is going to rise with it. Antibiotics are a very important part of the animal industry and have helped with the growing of animals that are used to meet that demand. The use of antibiotics in animal feed was a great discover and has shown numerous benefits over the decades. But the long-term use of antibiotics has negative effects to it, and those cannot be ignored. If society wants to avoid future public health concerns, the issue of antibiotic resistant bacteria in the animal industry must be addressed fully. There must be a push towards using alternatives that are safe for the animal, the consumer, and the environment that does not have the same effect of resistance that the antibiotics have. A safe alternative would be able to eventually replace antibiotics in animal feed and make for a safer future for consumer and producers in the animal industry.



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