August 2017
For What It’s Worth

Defining a “Closed Herd”


This photo captures essentials for isolation pen: secure fencing, shade, forages, shelter and water. Supplemental feeding may become necessary.

When it comes to livestock production, many of us have heard or read about the term “closed herd.” Closed herd refers to a system of biosecurity management practices designed to prevent the risk of disease being introduced into a herd and prevent the spread of disease within a herd. Sounds simple, but it is quite complex when trying to plan, implement and monitor. During my years of interaction with experts and small ruminant producers, I have heard this term used many times. And people’s perception of this term varies. It has always surprised me how liberal people are with such a serious issue that controls disease and insures animal health.

What diseases are of concern? Pink eye, sore mouth, internal and external parasites, Caseous lymphadenitis, caprine arthritis encephalitis, Johne’s disease and Q fever. These are the primary diseases, though the latter three do not occur very often. I am sure someone will come up with something like scrapie. (When was the last time there was an outbreak of that?) I am focusing on the more commonly occurring diseases.

What practices are utilized to maintain a closed herd?

Why do practices vary? Practices differ because of varying situations, ability to implement and personal choices. Let’s face reality and recognize that this is a very complicated process. It is challenging to keep a deer or stray animal from jumping the fence and contaminating a herd. Isolation pens require space and ability to sanitize area afterward. Artificial insemination requires expensive equipment and sources and conception rates are low. Heat treating milk and bottle feeding young is time-consuming. Catching every person or piece of equipment before they enter your property is a challenge.

As stated in the first paragraph, the definition and implementation of closed herd as a form of biosecurity varies. I hope this article provides you with some ideas to implement a practical style of biosecurity that works best for your farm. Coming up with a biosecurity plan requires a little bit of time and implementation, but not as much time as treating or euthanizing a herd of sick animals.



Biosecurity on U.S. Goat Operations.” USDA APHIS. Veterinary Services. Centers for Epidemiology and Animal Health. March 2012. Last retrieved June 2017.

Hemenway, Melanie, DVM. NYS Department of Agriculture & Markets. “Biosecurity for Goats (PowerPoint Presentation). Last retrieved June 2017.

Lee, Brenda. “Closed Herd Versus Open Herd.” Kalispell Kinders & More! February 17, 2013. Last retrieved June 2017.


Robert Spencer is an Urban Regional Extension Specialist with the Alabama Cooperative Extension System. You can contact him at This email address is being protected from spambots. You need JavaScript enabled to view it..