+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Improving accuracy of test interval method of calculating dairy herd improvement records



Improving accuracy of test interval method of calculating dairy herd improvement records



Journal of Dairy Science 57(5): 648



Daily milk weights from 1,033 complete 305 day lactations from eight herds were used to determine the filters of estimating actual lactation and test interval yields. Biases in a testing scheme with fixed 30 day intervals were 67.0, 65.8, and 10.3 kg for lactation total, interval to first,test, and interval after las,t test. Lactation number was an important source of variation in these biases, while breed, season of calving, and the two-factor interactions were unimportant. Correction factors for first and last intervals were obtained within parity groups as the ratio of average daily yield in the interval to test day yield. Factors for first interval were fitted by regression on days to first test and those for last interval by regression on square root of days from last test to 305 days. Use of the correction factors reduced biases to - 1 1.4, - 1.3, and - 1.1 kg for lactation and first and last intervals. Variances of the errors of estimation after correction were 94.3, 63.6, and 79.2% of those in the uncollected data.

Please choose payment method:






(PDF emailed within 1 workday: $29.90)

Accession: 026774105

Download citation: RISBibTeXText


Related references

Accuracy of test interval method of calculating Dairy Herd Improvement Association records. J. Dairy Sci, 51: 1936,, 1968

Test interval method of calculating dairy herd improvement association records. J Dairy Sci 51(1): 170-179, 1968

Accuracy of monthly, bimonthly, and trimonthly Dairy Herd Improvement Association records. J Dairy Sci 51(7): 1051-1058, 1968

Using a distribution of gestation lengths to estimate accuracy of breeding records in dairy herd improvement association herds. Journal of Dairy Science 65(Suppl. 1): 109, 1982

Improving your dairy herd through the National Cooperative Dairy Herd Improvement Program. 1980

Relationship of use of dairy herd improvement records to herd performance measures. Journal of Dairy Science 70(12): 2688-2694, 1987

List of sires proved in dairy herd improvement associations, 1943. Compiled by the Division of Dairy Herd Improvement Investigations, Bureau of Dairy Industry, Agricultural Research Administration. Misc. Publ. U.S. Dep. Agric, 522, 97. Price: 15 cents, 1943

List of sires proved in Dairy-Herd-Improvement Associations, 1951. Compiled by Division of Dairy Herd Improvement Investigations, Bureau of Dairy Industry, Agricultural Research Administration. Agric. Handb. U. S. Dep. Agric, 21, 218. Price: 50 cents, 1951

How DHI Dairy Herd Improvement cow records are calculated Milk production management, computerized records. 1982

Milk production records; continued dairy herd improvement possible when breeding program is based on adequate records. California Agric 3(6): 9, 1949

The future of the National Dairy Herd Improvement Association (NDHIA) Dairy cows, records, services. Dairy and food sanitation 3(2): 52-53, 1983

The purebred dairy industry use of Dairy Herd Improvement records. National cooperative dairy herd improvement program handbook Editor J Lee Majeskie, 1986

Computer capabilities through DHIA dairy herd improvement association in the State of Utah Dairy cows, records, health. 1982

Dairy Herd Improvement records: their need and use. Bulletin Cooperative Extension Service University of Georgia College of Agriculture: 84 (897), 1984

Survey of facility and management characteristics of large, Upper Midwest dairy herds clustered by Dairy Herd Improvement records. Journal of Dairy Science 98(11): 8245-8261, 2015