• Bom Harris, DVM

Why Do Farmers Use Antibiotics?


Alvis Dairy is one of two remaining dairy farms in Goochland County, Virginia. Erin Henley, part of the fourth generation currently working on this family-owned and -operated farm, oversees the health and welfare of their 850 lactating cows, as well as growing calves and dry (non-lactating) cows. Erin works six to seven days a week from dawn till dusk (and in the middle of the night at times) to ensure that her animals are healthy, comfortable and producing a wholesome product for her consumers.


Today, American consumers are very concerned about the use of antibiotics in food-producing animals. Let’s look at a few of the reasons why Erin might use antibiotics on her farm:

  • Calves: navel infections, pneumonia

  • Growing animals: pinkeye

  • Cows: mastitis (infection of the udder), metritis (infection of the uterus)


These conditions account for 99% of the antibiotics used on her farm. Using antibiotics is costly. First, the actual cost of a single antibiotic dose for a 1,500-pound animal is $20-60, depending on the drug used. Second, she must observe an appropriate withholding time (discard milk, do not sell for meat) after administering a drug to prevent residues in the food chain. But the greatest cost to the farm when the need for antibiotics arises is the effect of the disease on the long-term welfare and productivity of the animal. Calves with pneumonia or pinkeye do not grow as well or perform as well once lactating, even when the disease is appropriately treated and cured by an antibiotic. Cows with mastitis do not always recover milk production in the affected quarter. Cows with uterine infection post-calving do not transition into lactation well and are prone to other post-partum diseases such as ketosis and displaced abomasum.


For these reasons, Erin’s goal when managing her cows is to minimize the need for any treatments, including antibiotics, by meticulous management of the environment to maximize cow comfort and cleanliness, a healthy balanced ration designed by her nutritionist, and working closely with her veterinarian to appropriately vaccinate animals and catch problems early.

By ensuring that her calves get a healthy dose of colostrum and appropriate vaccination, she has very little disease in her calves. It is rare to see any kind of sickness in her weaned and growing calves. This year, we dealt with a severe pinkeye outbreak in this group. Adjustments were made, including improving fly control, clipping pasture and using a pinkeye vaccine, to get the outbreak under control and minimize the number of cases that need to be treated with antibiotics. In her lactating cows, she carefully monitors her cows that have recently calved, providing nutritional supplements such as calcium or probiotics when needed, to prevent postpartum problems. When cows develop an udder infection, she cultures the affected milk and only treats after determining if antibiotics will be effective in treating the infection. By performing these cultures, she cuts her antibiotic use to around ⅓ of what she would use if she treated all affected cows. The untreated cows are allowed to self-cure. Milk from both treated and untreated cows is discarded until the milk is clear of infection, inflammation and drug residues.


Prohibiting the use of antibiotics in food-producing animals is a major welfare concern. Food-producing animals are living creatures, and they develop infections just like humans. It would be cruel to allow an animal to suffer or die from treatable conditions to avoid the use of antibiotics. Farmers work hard to prevent disease and minimize the use of antibiotics. When they do use antibiotics, they are careful to observe the required milk and meat withholding to ensure that the food supply is kept safe. Whether you buy organic or not, due to the hard work of America’s farmers, veterinarians and food safety inspectors, you can be sure the food you purchase in the store is free of unsafe residues.

Do you have more questions about the use of antibiotics in farm animals? Contact these veterinary or farm resources for more information:

Virginia Academy of Food Animal Practitioners (VAFAP)

Virginia Veterinary Medical Association

Virginia Cooperative Extension

#dairy #cattle #beef #antibiotics #goochlandveterinarian

© Old Dominion Veterinary Services.

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