INTERBULL Routine Genetic Evaluation for Conformation Traits

May 2002

Introduction

International genetic evaluations for 18 conformation traits of Holstein and Jersey bulls from Australia, Belgium, Canada, Denmark, France, Finland, Germany, Hungary, Italy, the Netherlands, New Zealand, Poland, Spain, Switzerland, Sweden, the United Kingdom, and the United States of America were computed in this routine evaluation.

New data (national genetic evaluations) included in this evaluation:

• Change in trait definition or evaluation procedure for Australia (Overall udder), and New Zealand (Chest Width).
• Hungary changed their classification scale from a 50 points scale to a 9 points scale and provided two new traits: teat length and overall feet & leg.

Changes in Interbull procedures:

• A weighted bending procedure was implemented to obtain positive difinite correlation matrices (number of common bulls was used as weighting factor).

Data and method of analysis

Data were national genetic evaluations of AI sampled bulls with daughters in at least 10 herds. Table 1 and Table 2 presents the amount of data included in this Interbull evaluation for Holstein and Jersey, respectively. Table 3 gives trait definitions as provided by participating countries.

Estimated genetic parameters are shown in APPENDIX I and APPENDIX II for Holstein and Jersey, respectively. Parameters are listed by trait and country.

National proofs were first de-regressed within country and then analysed jointly with a linear model including the effects of evaluation country, genetic group of bull and bull merit. Heritability estimates used in both the de-regression and international evaluation were as in each country's national evaluation (Table 3).

Ancestor-bulls without own proofs were traced back two generations from the oldest bulls with proofs in order to increase across country connections and account for the effect of selection.

Genetic groups were defined according to unidentified parents by national origin, breed and birth year of the bull and path of selection (sire, maternal grand-sire, maternal grand-dam). Birth year grouping was by 1-5 year periods. Smaller groups (consisting of less than 15 bulls) were combined.


Publication of INTERBULL evaluations

Results were distributed by the Interbull Centre to designated representatives in each country. The international evaluation file comprised international proofs expressed on the base of each country included in the analysis. Such records readily provide more information on bull performance in various countries, thereby minimising the need to resort to conversions.

At the same time, all recipients of Interbull results are expected to honour the agreed code of practice, decided by the Interbull Steering Committee, and only publish international evaluations on their own country scale. Evaluations expressed on another country scale are confidential and may only be used internally for research and review purposes.

Next routine international evaluation

The next routine international evaluation for dairy production, conformation and udder health traits is scheduled for August 2002. New data for that run should reach the Interbull Centre not later than August 2, 2002, 17:00 Central European Time (CET); in any case, the most recently received data will be considered. Results will be distributed on August 12, 2002.

Next test international evaluation

The next test international evaluation for dairy production traits, conformation traits, and milk somatic cell and clinical mastitis is scheduled for September 2002. Countries wishing to enter the system for the first time or planning to submit new information (modified national evaluation procedure, new breeds etc) for following routine evaluations must have their data tested in this test-run.

Deadline for sending data to the Interbull Centre for the next test-run is September 1, 2002.

Means of result distribution from the Interbull Centre

Electronic exchange of data is probably more efficient than anything else. Currently most countries in the service have established internet connections and receive international evaluation results on the day of their release. Subscribers to the service that do not already exercise this option are encouraged to consider it and establish an internet connection and ftp account. When such accounts are available, please provide their specifications to the Interbull Centre. Until then, data will be delivered on CD-ROM's.

For more information about the international genetic evaluation service please contact the INTERBULL Centre: address: SLU Box 7023, 750 07 Uppsala, Sweden;  fax: +46-18-672648;