February 2005

Introduction

The latest routine international evaluation for dairy production traits took place as scheduled at the Interbull Centre. Data from twenty six (26) countries were included in this evaluation. Results were distributed on February 9, 2005, to designated representatives.

International genetic evaluations for milk, fat and protein yields of bulls from Australia, Austria, Belgium, Canada, Czech Republic, Denmark, Estonia, Finland, France, Germany, Hungary, Ireland, Israel, Italy, Japan, Netherlands, New Zealand, Norway, Poland, Rep. of South Africa, Slovenia, Spain, Sweden, Switzerland, the United Kingdom, and the United States of America were computed. Ayrshire, Brown Swiss, Guernsey, Holstein, Jersey and Simmental breed data were included in this evaluation.

New data (national genetic evaluations) included in this evaluation

• The Netherlands included data from Luxembough. This data comes from a different organisation than the data included in the German evaluation, so there should be no double counting. At the same time genetic parameters and reference base are updated.
• Italy (Jersey) updated the reference base.
• USA modified their genetic evaluation to adjust for past inbreeding and expected future inbreeding, to adjust for differing parity standard deviations, to adjust to 36-month age instead of mature equivalent, and to update the base mean and SD. (Details can be found here: http://www.aipl.arsusda.gov/reference/base2005.htm)
• Hungary separated calculation of breeding values for production and milk somatic cell for both Simmental and Holsteins, respectively. Adjustment of heterogeneous variance is introduced for both breeds.
• Spain updated the reference base, including the base for the adjustment for heterogeneous variances.

Changes in previous test-run NOT introduced:

• ZAF (HOL)
• CHE (HOL, RHOL, BSW, SIM)

Changes in Interbull procedures

• Sires and dams can now have Y as authoritative pedigree code in pedigree. BREED when an "incorrect" bull ID was provided in the 010-file from the authoritative source (incorrect meaning that the ID provided in the 010-file was included in the cross- reference file as an ID not preferred by Interbull, i.e. the bull has code X in the 012 file). Previously such sire and dam codes were set to N per default. This change had an impact on 14, 5, 4, 516, 36 and 17 records in the pedigree. BREED for BREED ays, bsw, gue, hol, jer, sim, respectively. The authoritative source is encouraged to carefully check the pedigrees of bulls with code X and make sure to provide the preferred international ID in the future (or alternatively notify the Interbull Centre and concerned countries about a potential wrong cross reference).
   

Data and method of analysis

Data were national genetic evaluations of AI sampled bulls with daughters in at least 10 herds. Table 1 presents the amount of data included in this Interbull evaluation. The difference between "No. Records" and "No. Bulls" is explained by common bulls with proofs in more than one country. The entry "Publishable Proofs" reflects bulls whose international evaluations were distributed to service customers. The difference between "No. Bulls" and "Publishable Proofs" is explained by bulls not meeting the minimum criterion for official publication in the country of origin.

Table 2 and table 3 presents the current definition of the reference (genetic) base and date of evaluation, respectively, as supplied by each country in the dairy-production proof file.

Estimated genetic parameters are shown in APPENDIX I and the corresponding number of common bulls are listed in APPENDIX II. Parameters are listed by breed, 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. Different breeds were analysed separately. Heritability estimates used in both the de-regression and international evaluation were as in each country's national evaluation (Table 4).

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. Small groups (generally consisting of less than 10 bull) were combined.

Scientific literature

The international genetic evaluation procedure is based on international work described in the following scientific publications:

International genetic evaluation computation:

Schaeffer. 1994. J. Dairy Sci. 77:2671-2678
Klei, 1998. Interbull Bulletin 17:3-7

Verification and Genetic trend validation:

Klei et al., 2002. Interbull Bulletin 29:178-182.
Boichard et al., 1995. J. Dairy Sci. 78:431-437

Weighting factors:

Fikse and Banos, 2001. J. Dairy Sci. 84:1759-1767

De-regression and genetic parameter estimation

Sigurdsson and G. Banos. 1995. Acta Agric. Scand. 45:207-219
Jairath et al. 1998. J. Dairy Sci. Vol. 81:550-562

Genetic parameter estimation:

Sigurdsson et al., 1996. Acta Agric. Scand. 46:129-136
Sullivan, 1999. Interbull Bulletin 22:146-148

Time edits

Weigel and Banos. 1997. J. Dairy Sci. 80:3425-3430

International reliability estimation

Harris and Johnson. 1998. Interbull Bulletin 17:31-36

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 and calving traits (Holsteins) is scheduled for May 2005. New data for the May routine run should reach the Interbull Centre not later than Tuesday April 26, 2005, 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 May 5, 2005. Official release date of the results is targeted to be Monday May 9, 2005.

Next test international evaluation

The next test international evaluation for dairy production, conformation, udder health, longevity and calving traits (Holstein) is scheduled for March 2005. Countries wishing to enter the system for the first time or planning to submit new information (modified national evaluation procedure, newbreeds etc) for following routine evaluations must have their data tested in this test-run.

Deadline for sending data and validation results to the Interbull Centre for the March 2005 test evaluation is March 1, 2005 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.