Interbull Routine Genetic Evaluation for Conformation Traits

Augusti 2008

Introduction

International genetic evaluations for conformation traits of Brown Swiss, Guernsey, Holstein, Jersey and Red Dairy Cattle bulls from Australia, Belgium, Canada, Czech Republic, Denmark, Estonia, France, Finland, Germany, Hungary, Italy, Japan, the Netherlands, Norway, New Zealand, Poland, Rep. of South Africa, Spain, Sweden, Switzerland, the United Kingdom, and the United States of America were computed in this evaluation.

New data (national genetic evaluations) included in this evaluation compared to the routine run in January 2008.

• POL: sent rear teat placement for the first time
   
• FRA (RHOL): added overall conformation, and changed from "teat direction" to "teat placement" for RTP trait
   
• DEU (HOL, RDC): Updated formula for calculation of overall conformation score.
   
• NZL: Developed a new program to produce Interbull files. Crossbred animals having the same number of 16ths for two breeds were assigned to the breed of their sire.
   
• DFS (HOL, RDC): Definition for Finnish data for foot angle has been changed from hoof angle to foot angle.
   
• DFS (JER): The pedigree is traced as for HOL and RDC. Composite indexes calculated in the same manner as for HOL and RDC
   
• CHE (BSW): Changed the definition of chest width (now chest width, previously circumference of chest), overall conformation score, overall udder score and overall feet & leg score (new formula for all three scores).
   
• CZE (HOL): Data for two traits are submitted for the first time (Rear legs rear view and Rear teat placement). Proofs in form of relative breeding values (100;12). (Previously (0;3)). Base for relative breeding values is determined by animals born in 1995. New genetic parameters estimated.
   
• CAN: Change in indication of official publication of proofs: current requirement for 'Y' is at least 10 herds
   
• USA: (HOL): Changed genetic evaluation model for the linear traits.
  A. Included more pedigree data and more rounds of iteration (same change as implemented before with overall conformation).
  B. All linear traits are now done in a Multi-Trait model, previously all original linear traits were done in a MT model and new traits (eg. teat length, rear legs rear view, feet & leg score and rear teat placement) were done in a ST model.
  C. New heritablities and Standard deviations were used
   
• ITA (BSW): From the August (2008) evaluation onwards Italy (BSW) has decided not to participate in IGE for angularity.

Changes in the Interbull procedures

• none
   

Data and method of analysis

Data were national genetic evaluations of AI sampled bulls with daughters in at least 10 herds. Table 1, table 2, table 3, table 4 and table 5 presents the amount of data included in this Interbull evaluation for Brown Swiss, Guernsey, Holstein, Jersey and Red Dairy Cattle, respectively. Table 6 gives trait definitions as provided by participating countries.

Estimated genetic parameters are shown in APPENDIX I, APPENDIX II, APPENDIX III, APPENDIX IV and APPENDIX V for Brown Swiss, Guernsey, Holstein, Jersey and Red Dairy Cattle, 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 6).

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.

Analysis followed a similar procedure as Mace for production traits.

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 and unit 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.

All recipients are also expected to follow the agreed guidelines for advertising genetic merit. The guidelines has been distributed to all members and is available on the Interbull homepage (http://www.interbull.org) under "Publications and Documentation/General information".

Next routine international evaluation

The next routine international evaluation for dairy production, udder health, conformation, longevity, calving (Brown Swiss, Holsteins, Red Dairy Cattle) and fertility traits is scheduled for January 2009. New data for the January routine run should reach the Interbull Centre not later than Tuesday Dec 9, 2008, 17:00 Central European Time (CET); in any case, the most recently received data will be considered. The target time for distribution of results for internal review to designated representatives, who have signed a confidentiality agreement with the Centre, is Thursday January 8, 2009. Official release date of the results is targeted to be Tuesday January 13, 2009.

Next test international evaluation

The next test international evaluation for dairy production, conformation (incl. locomotion and BCS), udder health, longevity, calving (Brown Swiss, Holstein, Red Dairy Cattle), female fertility, and workability traits is scheduled for September 2008. 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.

Countries participating in the calving trait evaluation should submit MT-EDC's for calving traits for the September 2008 test run.

Deadline for sending data and validation results to the Interbull Centre for the September 2008 test evaluation is September 9, 2008 at 17:00 CET.

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;

Please use Interbull_at_hgen.slu.se for all communication regarding Interbull services.