Interbull Routine Genetic Evaluation for Female Fertility Traits

May 2007


Introduction

International genetic evaluations for female fertility traits of bulls from Belgium (BEL), Czech Republic (CZE), Ireland (IRL), Israel (ISR), Italy (ITA), The Netherlands (NLD), New Zealand (NZL), Nordic countries (DFS: Denmark, Finland, Sweden), Spain (ESP), Switzerland (CHE and CHR, for Holstein and Red Holstein, respectively), United Kingdom (GBR), and The United States of America (USA) were included in this evaluation. 

Female fertility traits used in this Interbull test evaluation were classified as follows: 

T1 (HC): Maiden (H)eifer's ability to (C)onceive. A measure of confirmed conception, such as conception rate (CR), will be considered for this trait group. In the absence of confirmed conception an alternative measure, such as interval first-last insemination (FL), interval first insemination-conception (FC), number of inseminations (NI), or non-return rate (NR,preferably NR56) can be submitted;
    
T2 (CR): Lactating (C)ow's ability to (R)ecycle after calving. The interval calving-first insemination (CF) is an example for this ability;
 
T3 (C1): Lactating (C)ow's ability to conceive (1). A measure of confirmed conception, such as conception rate (CR), will be considered for this trait group. In the absence of confirmed conception an alternative measure, such as interval first-last insemination (FL), interval first insemination-conception (FC), number of inseminations (NI) can be submitted;
 
T4 (C2): Lactating (C)ow's ability to conceive (2). A measure of confirmed conception, such as conception rate (CR), will be considered for this trait group. In the absence of confirmed conception any measurement with relevance to conception such as interval first-last insemination (FL), interval first insemination-conception (FC), number of inseminations (NI), non-return rate (NR, preferably NR56), days open (DO), or calving interval (CI) can be submitted;
    
T5  (IT): Lactating cow's measurements of (I)nterval (T)raits calving-conception, such as days open (DO) and calving interval (CI).

Changes in national procedures

Changes in the national genetic evaluation of female fertility traits are as follows:

CZE: This is the first routine evaluation for CZE.
DFS: NR was submitted as T1 and T4 (previously submitted traits: FL, NI).
USA: Data from an all-breed evaluation submitted.

Changes in Interbull procedures

There has not been any change in the Interbull procedures since the latest evaluation.

Data and method of analysis

Traits submitted by the participating countries are presented in Table 1.

Data were national genetic evaluations of AI sampled bulls with at least 10 daughters in at least 10 herds. Table 2 presents the amount of data included in this Interbull evaluation for Holstein. 

Information on the expression of national genetic evaluation results, (T)ransmitting abilities or (B)reeding values, and whether higher or lower values are desirable are presented in Table 3.

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 4).

Table 5 presents the date of evaluation as supplied by each country in the 019-proof file.

Estimated genetic parameters are shown in APPENDIX I and the corresponding number of common bulls are listed in APPENDIX II. 

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). Minimum group size was set to 30.

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:

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
http://www.interbull.org/documents/genetic_correlation_estimation_procedure.pdf 

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 evaluation of Interbull for production, conformation, udder health, longevity, calving (Holstein, Red Dairy Cattle breeds, Brown Swiss), and female fertility (Holstein) traits is scheduled for August 2007. 

Deadline for sending data to the Interbull Centre is Tuesday July 31, 2007, 17:00 CET; confidential distribution of results is targeted for Thursday August 9, 2007, with earliest possible official release of results on August 13, 2007.

Next test international evaluation

The next test run for production, conformation, udder health, longevity, calving traits (Holstein, Red Dairy Cattle breeds, Brown Swiss), and female fertility (all breeds) will take place in September 2007. 

Countries planning to introduce changes in their national evaluation procedures and wishing to have them included in the routine Interbull evaluation, should have their data examined in this test run. New data and validation results for the September test-run should be sent to the Interbull Centre no later than September 4, 2007, 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: Freddy.Fikse_at_hgen.slu.se Phone: +46-18-671994
Flavio.Forabosco_at_hgen.slu.se +46-18-671974
  Jette.Jakobsen_at_hgen.slu.se   +46-18-671955
Eva.Hjerpe_at_hgen.slu.se +46-18-672438
Hossein.Jorjani_at_hgen.slu.se +46-18-671964
Jan.Philipsson_at_hgen.slu.se +46-18-671976
Dan.Englund_at_hgen.slu.se +46-18-671968

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