Interbull Routine Genetic Evaluation for Dairy Production Traits

August 2008


The latest test international evaluation for dairy production traits took place as scheduled at the Interbull Centre. Data from twenty seven (27) countries were included in this evaluation. Results were distributed on August 14, 2008, 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, Latvia, Netherlands,New Zealand, Norway, Poland, Rep. of South Africa, Slovenia, Spain, Sweden, Switzerland, the United Kingdom, and the United States of America were computed. Brown Swiss, Guernsey, Holstein, Jersey, Red Dairy Cattle and Simmental breed data were included in this evaluation.

New data (national genetic evaluations) included in this evaluation

USA RDC Inluded MSH bulls in the RDC analysis.
NZL ALL New program was used to create the Interbull files
DFS HOL Included Swedish test day data in the evaluation
ITA HOL Tested a new evaluation for yield (new data editing model including single year effect instead of a 5 year class group, data pre-adjusted for days pregnancy)
NOR RDC new criterion to set official status of proof
GBR ALL New genetic parameters estimated for production..Removal of herd-sire effect from the model. Fitting of fixed lactation curves within calving year(groups)-season-age subclasses instead of season-age subclasses. Inclusion of lactatins 4 and 5 as repeats of lactation3
EBV was computed as an average of EBV for lactation 1,2,3  regardless the number of daughters per lactation (previously requirement for at least 20 daughters). The birht (2000) year of cows included in genetic reference base is the same for lactation 1,2,3. (Previously 2000 for lactation 1, 1999 for lacatation 2, 1998 for lactation 3)The number of age classes (lactation 1) and calving interval classes (lactation 2,3) is increased to 15 respectively 12 (Previously 3 resp. 3). Natural services bulls not  included in the evaluation (according to demand of breeding associations).
CAN ALL Change in indication of official publication of proofs: current requirement for "Y" is at least 10 herds. Minor change in the way contemporary groups are assigned.

Changes in Interbull procedures

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


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:

Klei and Weigel, 1998, Interbull Bulletin 17:8-14
Sullivan, 1999. Interbull Bulletin 22:146-148

Post-processing of estimated genetic correlations:

Mark et al., 2003, Interbull Bulletin 30:126-135
Jorjani et al., 2003. J. Dairy Sci. 86:677-679
Genetic correlation estimation procedure

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 ( under "Publications and Documentation/General information".

Next routine international evaluation

The next routine international evaluation for dairy production, udder health conformation, longevity,calving traits (BSW, Holstein, RDC) and female fertility is scheduled for January 2009. New data for the January routine run should reach the Interbull Centre not later than Tuesday December 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, 2008. 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, udder health, longevity and calving traits (Red dairy cattle breed, Brown Swiss, Holstein) and female fertility 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.

Deadline for sending data and validation results to the Interbull Centre for the next test-run 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;

e-mail: Phone: +46-18-671974   +46-18-671955 +46-18-672438 +46-18-671964   +46-18-671975 +46-18-671976 +46-18-671968

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