Antibiotic Use in Livestock
How does antibiotic resistance in livestock affect humans?
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Antibiotic use in livestock can have consequences that reach far beyond the boundaries of your farm. Learn how, and the best way to use them.
THE DEVELOPMENT OF antibiotics has been one of the most spectacular success stories in medical history. These medications save countless lives, both human and livestock. Unfortunately, nothing is perfect, and antibiotic resistance is now regular.
Antibiotics are chemical substances produced naturally, semi-synthetically, or entirely synthetically. While they’re widely used as growth promoters in livestock, their primary purpose is to kill or inhibit bacterial growth.
Antibiotics are classified as either broad or narrow-spectrum. Broad-spectrum antibiotics work against multiple strains of bacteria that share common structures and metabolic functions. Narrow-spectrum antibiotics are more specific and target only certain bacteria.
How does antibiotic resistance occur?
The condition arises when bacteria no longer respond to the drugs designed to kill them. Infections stemming from antibiotic-resistant bacteria can be difficult or even impossible to treat. Antibiotic resistance is a global issue. It’s more prevalent in some nations over others, depending on the degree of consumption and government policy. The matter is one of the world’s most pressing public health issues.
Many of the current difficulties with antibiotic resistance stem from overuse or misuse of the drugs.
Many of the current difficulties with antibiotic resistance stem from overuse or misuse of the drugs. Antibiotics are often used irrationally for things they can’t treat (such as viral infections), or they’re not used correctly (such as failing to finish an entire course of treatment even after showing improvement).
Low dose antibiotic use in livestock.
In commercial livestock, animals are often routinely given low doses of antibiotics in their feed as a precaution (prophylactic use), even without disease, to prevent potential infections from developing. Sometimes, an entire herd is dosed with antibiotics after one animal gets sick, or animals receive antibiotics in their feed regardless of the need.
It’s often considered easier to use antibiotics than to address causative disease factors such as overcrowding, unclean facilities, or other conditions that might prevent infections from happening in the first place.
The widespread use of low-dose antibiotics for preventative maintenance in goats seems more prevalent in commercial herds. Small-scale holders report they’re more likely to medicate only sick animals.
Small farmers also tend to have healthier conditions: More outdoor access (which aids in building a robust immune system); kids staying on the does for extended periods (which improves healthy gut colonization); less crowding; cleaner facilities; and other non-medicinal ways to keep animals healthy.
How does antibiotic resistance occur from livestock to humans?
The issue of antibiotic resistance in livestock is no joke, in large part because of its effects on human health. Many resistant bacteria are also pathogens to humans, and many common human antibiotics are also used on livestock.
Therefore, resistant microorganisms can be transmitted up the food chain and into the environment via animal waste (such as fertilizing crops with manure, which enters the water system). Soil and water have been regarded as vital reservoirs and sources of antibiotic resistance.
Antibiotic resistance can lead to complicated, prolonged, or untreatable infections in humans, with corresponding healthcare costs and even mortality. According to the Centers for Disease Control and Prevention (CDC), antibiotic resistance is responsible for 23,000 annual deaths in the U.S. As many as two million U.S. individuals develop a drug-resistant infection each year.
Medical News Today states, “By the year 2050, some researchers predict that antibiotic resistance will cause 10 million deaths every year, surpassing cancer as the leading cause of mortality worldwide.”
Antibiotic residues and resistant bacteria are considered environmental pollutants and, in some places around the world, have contributed to public health crises.
Not only does widespread usage of antibiotics in livestock increase antibiotic resistance but it may also result in antibiotic residues in animal products for human consumption (meat, fat, organs, milk, eggs, etc.).
Limiting antibiotic use in livestock.
Some developed countries are limiting or ceasing the use of antimicrobials to promote growth in food animals, with no loss of production. However, this isn’t always an option in developing countries where tropical diseases can wipe out entire livestock categories if not aggressively and preventatively treated.
While it’s easy to say prophylactic antibiotic use should be limited and to criticize farmers’ indiscriminate use of antibiotics, this is harder to implement in underdeveloped countries where diseases can be widespread and devastating and government regulation is less prevalent.
A clear example of antibiotic resistance is how misusing goat penicillin causes human health concerns. Penicillin is a wonder drug, one of the first antibiotics discovered almost a century ago, and it remains one of the most widely used today.
It’s also the most commonly used antibiotic in goats for bacteria-caused respiratory illnesses, skin diseases, and throat infections. It can also treat pneumonia, foot scald, hoof rot, and mastitis.
The overuse of antibiotics in agriculture raises the risk of transmitting drug-resistant bacteria to humans.
Penicillin can be broad-spectrum or narrow-spectrum. A narrow-spectrum drug can treat illnesses with identified causes. But where goat research or veterinary care is rare (often in underdeveloped nations), farmers resort to broad-spectrum penicillin, which is less efficient and more likely to cause side effects.
But using penicillin — or any other antibiotic — too often will create immunity to the bacteria, which won’t respond further to the same medicines. The overuse of antibiotics in agriculture raises the risk of transmitting drug-resistant bacteria to humans.
According to the science journal Evolutionary Applications, the three mechanisms for transmitting to humans are (1) direct infection with resistant bacteria from an animal source; (2) breaches in the species barrier followed by sustained transmission in humans of resistant strains arising in livestock; and (3) transfer of resistance genes from agriculture into human pathogens. The most common mechanism is direct infection.
Nicola Evans, a doctoral researcher in structural biology at King’s College London, told Medical News Today, “Any single time antibiotics are used, whether in animals or humans, you risk selecting for drug-resistant bacteria. We need to safeguard [antibiotics] for use in both animals and humans to ensure they can be used for the treatment of infection in the future … I think that all use of antibiotics poses a risk to human health, and reducing unnecessary antibiotic use in animals should be part of the overall solution.”
What’s the best antibiotic for goats?
Many factors are involved, so there’s no one-size-fits-all answer. However, the most commonly used caprine antibiotics include Penicillin G, Procaine (penicillin), and Tylan 50 (Tylosin). Dosage rates, frequency, and duration depend on the animal’s age, health, and the nature of the infection. Consult a veterinarian to decide the correct course of action.
If you need to treat your animals with antibiotics, don’t hesitate, but don’t misuse or abuse the medication. Rather than dosing your animals with low levels of antibiotics, address conditions that may cause the animals to get sick in the first place. Make sure facilities are clean, dry, and not overcrowded.
Preventing antibiotic resistance is a global issue and far beyond the scope of any one caprine owner. However, it’s incumbent upon us all to do our part.
PATRICE LEWIS is a wife, mother, homesteader, homeschooler, author, blogger, columnist, and speaker. An advocate of simple living and self-sufficiency, she has practiced and written about self-reliance and preparedness for almost 30 years. She is experienced in homestead animal husbandry and small-scale dairy production, food preservation and canning, country relocation, home-based businesses, homeschooling, personal money management, and food self-sufficiency. Follow her website www.PatriceLewis.com/ or blog www.Rural-Revolution.com
SOURCES:
- https://www.cdc.gov/antibiotic-use/antibiotic-resistance.html
- https://phys.org/news/2020-08-antibiotic-resistance-drug-misuse-livestock.html https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6017557/ (Evolutionary Applications)
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4380918/
- https://web.archive.org/web/20190426153041id_/
- http://www.asmscience.org/docserver/fulltext/microbe/6/6/znw00611000274.pdfexpires=1556293530&id=id&accname=guest&checksum=14DDE8583F3E031E62D64D90FE526E2
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6262384/
- https://www.medicalnewstoday.com/articles/323639
- https://lifeoffarmers.com/antibiotics-for-goats/
- https://justagric.com/best-antibiotics-for-goats/
- https://healthhearty.com/narrow-spectrum-vs-broad-spectrum-antibiotics
- https://socratic.org/questions/what-is-the-difference-between-a-broad-spectrumand- narrow-spectrum-antibiotic
