DH-123 • Rev. 1977
animal sciences dairy
COOPERATIVE EXTENSION SERVICE PURDUE UNIVERSITY, WEST LAFAYETTE INDIANA 47907
Dairy Herd Testing Programs
Will Dillon, Animal Sciences Department, Purdue University
Dairy herd testing can mean higher income and greater satisfaction from dairy farming. For more than 70 years, various testing programs have been made available to help dairy farm families improve herd performance. Today, herds of all types and sizes, as well as both registered and grade cattle, are on test.

Dairy herd testing is offered throughout Indiana by joint effort of the Cooperative Extension Service and local Dairy Herd Improvement Associations (DHIA). An association is a group of dairymen who have organized (on a single- or multi-county basis) to obtain production testing service. This service is provided by an employee called a "supervisor." The supervisor’s job is to gather the necessary information from each participating herd, test the milk for fat content and fill out the forms for computer processing, analysis and summarization.

Each DHIA is a member of the Indiana State Dairy Association, Inc. (ISDA), which helps coordinate production testing efforts and represents dairy farmer interests at the state and national level.
TYPES OF TESTING PROGRAMS
Dairy Herd Improvement Program
The Dairy Herd Improvement (DHI) record is the oldest and most popular type of test. Here, the supervisor visits the farm once a month to weigh and sample milk, help identify cows and report detailed information on feeding, breeding and management activities. Both evening and morning milkings are weighed and sampled to estimate the 24 hours of production.
DHI records are authenticated by the supervisor, because it is he who collects and verifies all of the information. Cost of the service varies from association to association and is in proportion to herd size; but generally, the charges range from $1.00 to $1.25 per cow per month.

Dairy farmers use these records to: (1) identify the low producers that are causing extra work and costing money; (2) develop better feeding programs that get more feed converted into milk; (3) help pinpoint mastitis-problem cows and difficult breeders; (4) check the year-to-year progress in development of a balanced dairy operation; (5) identify cows to sell as breeding stock; (6) help sell young sires to other dairymen or AI organizations; (7) establish loss of income and cattle value in case of fire or other disaster; and (8) earn local, state and national recognition for an excellent dairy operation.
DHI records are also used in extension programs, research studies, pedigree and sale publicity, and sire and cow evaluation. They are recognized by the U.S. Department of Agriculture and the dairy cattle breed associations.

Dairy Herd Improvement Registry Program
The Dairy Herd Improvement Registry (DHIR) records, which are also USDA- and breed association- recognized, are made on essentially the same basis as DHI records, but with additional rules relative to enrollment, cow identification and surprise test as specified by the breed associations. The breeder must make arrangements with his breed association to start or stop DHIR.