Why - and How - We Use Antibiotics

"You don't use antibiotics in your sheep, do you?" When we sold meat at our local farmers market, we got this question frequently. Since we don't sell directly to consumers much anymore, the question comes less often - but we still occasionally get asked whether we give our sheep antibiotics. The short answer is "yes." But the long answer is more complicated, and I hope you'll keep reading.

The debate over antibiotic use in livestock production, like many of our public policy debates, seems to occur at at least two levels. At the scientific level, the debate (as I understand it) seems to be about the conditions under which antibiotics are used - both in human medicine and in livestock production. At the public policy level, unfortunately, much of the information and recommendations generated by the scientific debate seems to disappear. Fear about antibiotic resistance and "super bugs" leaves little room for rational discussions about the value of antibiotics in livestock production.

Antibiotics can be used therapeutically (to treat infection), prophylactically (to prevent infection), or subtherapeutically (mostly to increase feed conversion efficiency - or increase rate of weight gain). Of these three uses, subtherapeutic use seems to have the greatest potential for creating antibiotic resistance - although managed correctly, this use can be safe, as well. In our operation, however, we only use antibiotics to treat infection.

Our go-to antibiotic is oxytetracycline (sold as LA-200), although we've also used penicillin on occasion. We use these medicines to treat things like foot rot infections and pneumonia in mature sheep, or navel ill and joint ill in lambs. These types of infections cause moderate to extreme discomfort - and sometimes death. Timely treatment with antibiotics can save a sheep's life.

A cynic (or an opponent of animal agriculture) might say, "So you use antibiotics to save a life that will only be taken later on." While we do raise sheep as a business, and while our business only receives income, ultimately, from the production of meat, our underlying motivations are far more complex. We raise sheep because we love working with animals. Our sheep convert grass and weeds (what some people in our part of the foothills call fuel load or fire danger) into muscle, fat, bone, wool, and milk. We take great pride in producing something that helps feed our community. In addition to providing a home for our sheep, the 300-plus acres we graze each year are home to a variety of native plants and wildlife. Our sheep - and our family - are part of an intricate system. And this system sometimes includes microbes that can cause deadly infections. Antibiotics, used correctly, can help us coexist.

So how do we use antibiotics correctly? Here in California, livestock antibiotics require a prescription from a veterinarian. These prescriptions are far more than a piece of paper. For a veterinarian to write me a prescription s/he must know me and my livestock - we must have what's called a "veterinarian-client-patient relationship." Once I have this prescription, which specifies the medicine and the conditions for which it can be used, I can buy the product.

I also must use these antibiotics according to the label instructions. The label specifies the species of livestock that the antibiotic can be used to treat, the conditions for which it can be used, the dosage, and the route of administration (e.g., subcutaneous, intramuscular, intravenous, orally, etc.). Perhaps most importantly, the label specifies a slaughter (and for dairy animals, a milk) withdrawal time - a period of time that I must wait before harvesting that animal. Failure to abide by this withdrawal time carries penalties - federal inspectors at the harvest facilities we use test for residues, and a violation of the withdrawal period has financial and other implications.

Each of our sheep carries an individual identification tag from the day they are born or bought. Whenever we treat an animal, we record this number. When we sell animals, we check the sale numbers against our list of treated animals. Anything that has not completed its withdrawal time isn't sold.

Since we moved our sheep back to the foothills from a valley alfalfa field in mid December, we've treated a number of ewes for foot infections. The heavy soil in the valley stuck between their toes, causing a sore. This sore invited infection between their hooves - an infection we have not been able to treat with topical products. The pain is severe enough that an infected ewe will spend more time laying down than grazing - causing her to lose weight. We've found that a single injection of LA-200 seems to clear up the infection. I treated several ewes this morning for this condition.

Antibiotics are an important tool in our operation, but they are only a tool - and a costly one at that. The folks who say we only use antibiotics to preserve our income miss this piece of the conversation, in my mind. Prevention, generally, costs less than treatment - good nutrition, solid management, and a thoughtful vaccination program prevent most of our disease problems. Treating a disease with antibiotics costs money - the shots I gave this morning cost me approximately $2.50 per ewe. Our gross margin per ewe is about $100, so this single treatment reduces our profitability by 2.5%.

Consumers have every right to ask about how I produce lamb and wool, but complex issues don't lend themselves to thoughtful discussion on Facebook or Twitter (or perhaps even in a blog post). Responsible use of antibiotics extends to all of us, I think. How many of us have quit taking antibiotics prescribed by our doctors once we're feeling better - rather than complete the entire course of treatment? We all have a role in this system!