International and national genetic evaluation of beef cattle
validation of national genetic evaluation models
After a workshop in Kuopio held in June 2006, Interbull decided to go forward with the development of a system for beef international genetic evaluation and a three year project called Interbeef was launched in June 2007. The participating countries are so far limited to Europe and the only trait evaluated at present is adjusted weaning weight (weight at 200 days). The results from a first international genetic evaluation have been shared with the countries but are not yet official. The evaluation is based on data from purebred Charolais and Limousin. To achieve good estimates of proofs in an international context it is important that methods for data validation and model selection are implemented. Here a validation method A is suggested that have been specifically developed to suit beef data. This study was based on data from Sweden, Denmark, the United Kingdom (UK) and Ireland. The French dataset was not investigated due to limited computer capacity. Method A involved calculations of Akaike?s Information Criterion (AIC) of three tests models. An approved model either had the lowest AIC value or differed no more than 5 % from the model with the lowest AIC. The models analyzed in this study were of adequate quality. The results also indicated that interactions had a large impact on the AIC. This study also includes a review of the national genetic evaluations, including research in the genomic area, performed in Sweden, Denmark, the UK, Ireland and France. Comparisons are made between the national genetic evaluations of beef cattle, the international genetic evaluation of dairy cattle and the work performed in Interbeef on beef cattle.