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Learn about the significance of international dairy bull evaluations through the Interbull Centre in Uppsala, Sweden. Discover how foreign data improves prediction accuracy and influences breeding decisions worldwide. Explore the impact of minimum reliability requirements on selecting top bulls for genetic improvement.
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Usefulness of international dairy bull evaluations Rex L. Powell Animal Improvement Programs Laboratory Agricultural Research Service, USDA, Beltsville, MD rpowell@aipl.arsusda.gov
Interbull Formed • IDF and EAAP activities • 1982 - Leningrad meeting • 1983 - Interbull formed • 1988 - Became ICAR committee • 1991 - Centre established
Interbull Centre • Site: Uppsala, Sweden • Responsibilities and activities: • Steering committee sets policy • General operations by staff • Global service provider
Interbull Evaluation Process • National evaluations sent to Centre • MACE combines pedigree and national evaluation data • Estimated genetic correlations applied • Evaluations returned to countries on their own scale • Officiality responsibility of countries
Sending Receiving 25 20 15 No. countries 10 5 0 Feb-99 Aug-94 Aug-95 Aug-99 Aug-96 Aug-97 Aug-98 Evaluation date Countries Participating in Service
Numbers of Countries per Bull 100 94.6 80 60 Percentage of Bulls 40 20 3.8 0.8 0.3 0.1 0.1 0.1 0.1 0.1 0 1 2 3 4 5 6 7 8 9+ Number of countries
Question Do foreign data aid in prediction of future national evaluations?
Data Best Predictor? NATIONAL NATIONAL Study Design 1995 1999
NATIONAL NATIONAL Study Design 1995 1999 r SD r SD
Data • February 1995 Interbull evaluations • National 1995 evaluations • National 1999 evaluations • Canada, Germany, Italy, Netherlands, USA
Answers • Foreign data improved prediction • Improvement greatest for imported bulls • Interbull evaluations should be official
Top 100 Bulls for Yield (USA)Based on Official Evaluations Source: Interbull and domestic, February 2001
Top 100 Bulls for Yield (NLD)Based on Official Evaluations Source: Interbull and domestic, February 2001
Top 100 Bulls for Yield (CAN)Based on Official Evaluations Source: Interbull and domestic, February 2001
Top 100 Bulls for Yield (HUN)Based on Official Evaluations Source: Interbull, February 2001
Top 100 Bulls for Yield (CSK)Based on Official Evaluations Source: Interbull, February 2001
Use of Reliability • Measure of accuracy • Guides how much to use a bull, not whether to use a bull • Minimum restricts the number of bulls • Limiting bulls limits progress
Impact of Minimum REL On Number of Bulls & Mean PTAP of Top 50 (USA) Source: Interbull, May 2001
Impact of Minimum REL On Number of Bulls & Mean PTAP of Top 50 (HUN) Source: Interbull, May 2001
Impact of Minimum REL On Number of Bulls & Mean PTAP of Top 50 (CSK) Source: Interbull, May 2001
Websites • interbull.org • Publications & bulletins • Evaluation summaries • aipl.arsusda.gov • Documents • Downloadable files • Access to all evaluations
Conclusions • Interbull Centre young and growing • Rankings differ by country • Foreign data improve prediction of later national evaluations • Most gain is from considering all bulls on one scale • Challenges remain in technical areas and in education
Foreign Bull Options • Top 100 on HGI • HGI as high as 10th HUN bull and • HUN REL 75% for production • HUN REL 70% for conformation • Nominated and approved
Foreign Bulls In & Out • 367 bulls on HGI combined list • Includes 68 of top 200 on US Net Merit • Bulls from all countries eligible for US NM$ list • 6 of top 12 for NM$ not included on HGI list (among them #2) • 3 of top 8 on TPI not included • #1 not included
Foreign Bulls Excluded 1Protein and REL from Hungarian scaled MACE 2Reliability of evaluation in home country of bull