I frequently have people ask what we feed our animals and they ask if the animals are given antibiotics. I am sometimes asked why antibiotics matter by bolder people who are willing to show a little lack of knowledge in order to learn more ... or possibly to test me to see if I know why it matters. From discussions with people asking about food given, it is apparent that many do no understand the role antibiotics and "medicated" feed play in the production of animal-based food. They have heard they are "bad" but don't really know why.
I do not use medicated feeds on my farm, but I do give sick animals antibiotics when they need them. Let me share a little about my understanding of antibiotics. Forgive me if it gets a bit medical-ish (as I am a RN), but it is a medical issue at least in part. I've read quite a few peer-reviewed published professional articles in medical journal (US and international), but I am not taking the time to cite them here. If this topic interests you, please research it more.
Antibiotics in some form have been used for centuries before the meridian of time, though their mechanisms and wide-scale products appears to be a convenience of the modern era. Around the 1940s and 1950s when penicillin was all the rage (becoming the #1 prescribed medication for humans), ranchers realized that when they treated sick animals living in high-density situations, they ended up gaining weight better and being healthier ... or, at least healthier during the finishing process.
What do I mean by finishing? Pretty much all beef (with veal being one possible exception) is grass-raised. They are turned out anywhere from small farms to huge ranges where they eat hay (dried grasses and legumes - legumes being things like alfalfa and clover), pasture (grasses and legumes still growing), or silage (fermented feed, such as corn silage made from the stalks). My limited experience is that silage is usually saved for dairy farms. Before beef is taken to market, they often gather them into high density holding areas where they are fed differently.
Holding before butchering (6-8 weeks or the rancher's variation of that) allows them to feed grain, often corn, in larger amounts. This helps change the flavor of the beef a little and fatten the cattle to prime butchering condition. I like the flavor of both grass-fed (without grain finish) and grain-finished beef.
Corn is not the cattle's natural feed source, though they do eat a little grain when they find grasses that have gone to seed. Grain is to cattle like cake or cookies are to humans - a treat. Because of the high density of animals and possible diseases, a "sub-therapeutic" level of antibiotics is often added to the grain. Sub-therapeutic means that the dose isn't strong enough to treat an illness, but is there preventatively. Currently, medicated feed is given without supervision of a veterinarian, though there are rumblings of this changing.
Medicated feed is given to all sorts of livestock including cattle, poultry, and hogs. I'm sure it's also available for sheep and goats, but I haven't paid attention. There are several issues with medicated feed.
First, wide-scale use of sub-therapeutic antibiotics has led to the evolution of drug-resistant strains. If you WANT drug resistant bacteria, this is how you do it. You take a large number of host creatures and give the enough antibiotics to kill the most susceptible microbes. The ones with greater resistance reproduce more - the more resistant, the more prolific they become. Microbes pick up genetic fragments from each other, so they can grab pieces of genetic material from others that are resistant. When it comes time to treat an illness, that drug doesn't work. Most drug-resistant microbes originate from animal populations managed with medicated feed. The antibiotic in medicated feed can be changed, which helps cultivate microbes resistant to multiple antibiotics.
Second, it's not natural for livestock to regularly consume antibiotics. Their bodies are designed to function with vast diversity of microbes in their rumen (stomach). Antibiotic treatment decreases the microbial diversity. As in humans, we have no idea what most of the microbes do, but its much more than simple digestion. For example, a newborn human with a sterile gut will die without microbes that establish in the gut - for one by bleeding to death. It enables effective digestion, but also plays a major role in the health of the entire creature. There are many studies that confirm that antibiotic courses decrease the diversity of microbes in the human gut on average 20-30%. A couple of months after the course of antibiotics, the numbers are back to normal, but diversity seems to be lost. This means that hundreds of species of microbes are permanently lost. The minimal research into this suggest they may be connected to all our health problems ... I don't know about that, but it makes sense to me they could be to many problems.
Third, I have read situations in which medicated animals have experienced or are in various stages of rumen (stomach) failure while in feedlot conditions. This has been among cattle and I know it can happen among sheep and goats. I suspect part of this is due to the high corn diet. When antibiotics are given, they kill part of the "normal flora" (normal microbes) which can allow pathogenic (disease-causing) microbes to boom as their competition is gone. Have you ever heard of "C-diff" in humans, which is Clostridium dificile. This microbe normally lives in our gut that when it overpopulates causes persistent (and especially foul) diarrhea. My experience has been that a few people pick it in their "normal" condition, but most develop it after a course of antibiotics. Similar things happen in cattle. The overall effect for most is that in the less active environment, off their natural diet, and with lower gut microbe diversity, they get fat. Hey - the same thing happens in humans when we are inactive, eat processed foods, and have decreased gut microbe diversity. In fact, many studies have shown a strong correlation between obesity, irritable bowel diseases, and autoimmune illnesses and poor microbial gut diversity - in humans.
I do not believe that antibiotics are evil. I think they are a wonderful tool to be used in certain circumstances. A specific example is a lamb named Celosia who developed an infection in her ear after getting her scabies tag, which is a small metal tag (see the below series of pictures ... I know they are low quality.
I clean the skin with iodine and alcohol first, and put antibiotic ointment on the piercing portion of the ear tag, but something got through. At first, I didn't know what was wrong with her because her whole head was swollen and she had a double-chin. Upon closer examination, I could tell the most intense swelling was around that ear. Her eye closest to the tag was swollen almost shut. I gave her a course of antibiotics and the swelling decreased about 50% after just one dose. I don't know if the infection would have killed her, but it was aggressive enough to potentially cause permanent disability and possibly sepsis (usually fatal "blood poisoning"). I completed the course of antibiotics because I wanted to make sure to kill off the culprit, not breed a super-bug. I've also used it with grain poisoning or when a new mother has retained membranes (I also treat the retainage ... humans usually get a D&C and antibiotics in the same situation) ... both of these are life-threatening emergencies, which can and do cause death.
My current conclusion on medicated feed and antibiotics? Medicated feed - I don't need it and don't use it. I'm okay with animals gaining weight as they are naturally designed to do. Antibiotics - I use it them when: 1) there is a high probability that the animal will die; 2) the illness is infectious and may spread through the herd or flock (like pink eye); or 3) the illness may cause permanent disability or illness (like coccidiosis that can scar up the intestines).
Wife to Brandon, mother to Tess and Liam, farmer, entrepreneur, cook & baker, nurse, and accountant who loves to try new things, travel, and work toward greater self-reliance.