Submitted to: American Dairy Science Association Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: July 26, 2000
Publication Date: N/A
Technical Abstract: For the August 2000 implementation of the first phase of a test-day model for US genetic evaluations of yield traits of dairy cattle, test-day data have been collected by the Animal Improvement Programs Laboratory (AIPL) for cows that have calved since 1990. The database includes more than 185 million test-day records from 24 million lactations. About 3.5 million observations are added each month. Test-day information is stored on a cow and herd basis. Cow information includes cow identification, herd code, calving date, days in milk, milking frequency, milk yield, fat and protein percentages, and somatic cell score. Herd information includes information on milk recording, such as sampling frequency, supervision received, and averaging of milk weights. Data are subjected to extensive validation. Results of record editing are carefully monitored to allow detection of potential problems with incoming records, such as an unusually high number of records that were replaced, deleted, or rejected. Test-day data are available to industry cooperators at the AIPL web site (http://aipl.arsusda.gov). Authorized users can query by cow or herd identification numbers and obtain test-day information. Error records from rejected test-day data also are available by querying on cow, sire, or herd identification numbers. Although test-day data were acquired for most herds, some gaps remain, particularly for the early 1990s. Some cows with lactation data do not have test-day data. The date for using test-day rather than lactation data in the national genetic evaluation system will be determined for each herd and based on the amount of test-day data available for that herd. For Holsteins, test-day records will be used for 42% of 1990 calvings, 78% of 1995 calvings, and >99% of 1999 calvings.