Dairy Herd Improvement Association (DHIA) is a national association that helps dairy producers create and manage records and data about their cows for use in making management decisions. The associations were originally organized by state, and as with many services, have consolidated into regional services.


The services that DHIA programs offer have also grown over the years. Traditional Milk testing and records services included milk production, milk fat, milk protein, Somatic Cell Count (SCC), as well as animal information on birth date, pregnancy, and number of lactations. Today, in addition to those services, milk testing can be used to determine pregnancy status, to examine nitrogen (N) efficiency as Milk Urea Nitrogen (MUN), and we are on the cusp of being able to diagnose and track Johne’s and Leukosis.

Each producer testing through Dairy One, can choose how often to test, and what information is of greatest value to them. Additionally, most of the data is managed by the DHIA technician or the farm in a computer program. The amount of data collected, and way it is stored and monitored, makes it a very powerful management tool.

Who is using DHIA testing? Nationally, there are 18,173 herds and 4,281,654 cows enrolled in DHIA services. This represents 39% of the herds and 46% of the cows in licensed herds in the U.S. In the Eastern US, there are 7,556 herds (43%) and 1,085,317 cows (55%) enrolled. In NY, 33% of the licensed herds are enrolled in DHIA, representing 58% of the cows.

Are DHIA herds bigger than others? The average herd size in the National DHIA testing system as of July, 2014 was 236 cows, and in the East, the average herd size is 144 cows. The average size of for all licensed herds was 196 cows, and 112 cows per herd in the East. Though DHIA herds might be slightly larger, they are pretty much the same as all licensed herds. “Licensed Herds” are those defines as herds currently shipping milk.

Does DHIA make a difference? The last statistic to look at is milk production. Milk production in all herds in the U.S. averaged 21,799 lbs/lactation, and those herds participating in DHIA testing averaged 23,682 lbs/lactation. Milk production increases are related to better management across the board, including animal health, milking practices, animal comfort, and personnel management.

Making decisions about where to spend money in your herd is always easier with the data to support the change. For more detailed information on DHIA testing, visit National DHIA and Dairy One DHIA Record Services.