Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: Investigation of An Alternative Approach to International Evaluations

Authors
item Vanraden, Paul
item Powell, Rex
item Emanuelson, Ulf - INBERBULL CENTRE

Submitted to: Interbull Annual Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 14, 2000
Publication Date: N/A

Interpretive Summary: To improve the accuracy of international evaluations of dairy cattle within current computing constraints, a selection index (SI) approach was developed to combine national evaluations with information from foreign relatives. The SI procedure, which includes sire and dam information, was compared with current international methods that use sire and maternal grandsire information with best linear unbiased prediction (BLUP) procedures. Bull evaluations for protein yield from eight countries (Canada, Belgium, Denmark, Estonia, France, Switzerland, The Netherlands, and the United States) were used to investigate differences between SI and BLUP methods. Differences between the two methods were fairly small, and correlations were about .99 for each country's scale. The SI evaluations were more consistent across countries. Accuracy of bull evaluations that included a dam contribution instead of only maternal grandsire information was higher and should agree more closely with accuracy of national evaluations from animal models. The SI approach was fast and also could be used to provide international evaluations for cows as well as bulls, which would provide a closer connection between national and international evaluations. Centralized processing of cow evaluations should be more efficient than two-way exchange of data files between each of the national centers.

Technical Abstract: A selection index (SI) approach was developed to combine national evaluations of cows and bulls with information from foreign relatives. The SI procedure, which includes sire and dam information, was compared with current international methods that use sire and maternal grandsire information with best linear unbiased prediction (BLUP) procedures. Bull evaluations for protein yield from eight countries (Canada, Belgium, Denmark, Estonia, France, Switzerland, The Netherlands, and the United States) were used to investigate differences between SI and BLUP methods. The Interbull Centre (Uppsala, Sweden) supplied national input records for February 2000, and eight national evaluation centers supplied sire and dam information for their bulls. Correlations between SI and BLUP evaluations of bulls ranged from .989 to .993 on the eight country scales. The SI evaluations were more consistent across countries; correlations for all country pairs ranged from .994 to .999 as compared with correlations of .987 to .996 for BLUP evaluations. Accuracy of bull evaluations that included a dam contribution instead of only maternal grandsire information was higher and should agree more closely with accuracy of national evaluations from animal models. The SI approach was fast (1.5 minutes of processing time per trait needed for the eight countries and 36,294 bulls) and also could be used to provide international evaluations for cows as well as bulls.

Last Modified: 10/23/2014
Footer Content Back to Top of Page